Global Warming Producing More Powerful Hurricanes

Hurricanes, Cyclones Gathering Strength

Editor’s Note: This study was published just weeks before Hurricane Michael rearranged the Florida panhandle.

The IPCC AR5 presents a strong body of scientific evidence that most of the global warming observed over the past half century is very likely due to human-caused greenhouse gas emissions. But what does this change mean for hurricane activity? Here, we address these questions, starting with those conclusions where we have relatively more confidence. The main text then gives more background discussion. Detectable change refers to a change that is large enough to be clearly distinguishable from the variability due to natural causes. Our main conclusions are:

  • Sea level rise–which very likely has a substantial human contribution to the global mean observed rise according to IPCC AR5–should be causing higher storm surge levels for tropical cyclones that do occur, all else assumed equal.
  • Tropical cyclone rainfall rates will likely increase in the future due to anthropogenic warming and accompanying increase in atmospheric moisture content. Modeling studies on average project an increase on the order of 10-15 percent for rainfall rates averaged within about 100 km of the storm for a 2 degree Celsius global warming scenario.
  • Tropical cyclone intensities globally will likely increase on average (by 1 to 10 percent according to model projections for a 2 degree Celsius global warming). This change would imply an even larger percentage increase in the destructive potential per storm, assuming no reduction in storm size.  Storm size responses to anthropogenic warming are uncertain.
  • The global proportion of tropical cyclones that reach very intense (Category 4 and 5) levels will likely increase due to anthropogenic warming over the 21st century.  There is less confidence in future projections of the global number of Category 4 and 5 storms, since most modeling studies project a decrease (or little change) in the global frequency of all tropical cyclones combined.
  • In terms of detection and attribution, much less is known about hurricane/tropical cyclone activity changes, compared to global temperature.  In the northwest Pacific basin, there is emerging evidence for a detectable poleward shift in the latitude of maximum intensity of tropical cyclones, with a tentative link to anthropogenic warming.  In the Atlantic, it is premature to conclude that human activities–and particularly greenhouse gas emissions that cause global warming–have already had a detectable impact on hurricane activity. Reduced aerosol forcing since the 1970s probably contributed to the increased Atlantic hurricane activity since then, but the amount of contribution, relative to natural variability, remains uncertain. There is some evidence for a slowing of tropical cyclone propagation speeds globally over the past half century, but these observed changes have not yet been confidently linked to anthropogenic climate change.  Human activities may have already caused other changes in tropical cyclone activity that are not yet detectable due to the small magnitude of these changes compared to estimated natural variability, or due to observational limitations.

climate change and hurricanes

Global Warming and Atlantic Hurricanes

A. Statistical relationships between SSTs and hurricanes

Observed records of Atlantic hurricane activity show some correlation, on multi-year time-scales, between local tropical Atlantic sea surface temperatures (SSTs) and the Power Dissipation Index (PDI) —see for example Fig. 3 on this EPA Climate Indicators site. PDI is an aggregate measure of Atlantic hurricane activity, combining frequency, intensity, and duration of hurricanes in a single index. Both Atlantic SSTs and PDI have risen sharply since the 1970s, and there is some evidence that PDI levels in recent years are higher than in the previous active Atlantic hurricane era in the 1950s and 60s.

Model-based climate change detection/attribution studies have linked increasing tropical Atlantic SSTs to increasing greenhouse gases, but proposed links between increasing greenhouse gases and hurricane PDI or frequency has been based on statistical correlations. The statistical linkage of Atlantic hurricane PDI to Atlantic SST suggests at least the possibility of a large anthropogenic influence on Atlantic hurricanes.

If this statistical relation between tropical Atlantic SSTs and hurricane activity is used to infer future changes in Atlantic hurricane activity, the implications are sobering.

The large increases in tropical Atlantic SSTs projected for the late 21st century would imply very substantial increases in hurricane destructive potential–roughly a 300 percent increase in the PDI by 2100.

On the other hand, Swanson (2008) and others noted that Atlantic hurricane power dissipation is also well-correlated with other SST indices besides tropical Atlantic SST alone, and in particular with indices of Atlantic SST relative to tropical mean SST. This is in fact a crucial distinction, because while the statistical relationship between Atlantic hurricanes and local Atlantic SST shown in the upper panel of Figure 1 would imply a very large increases in Atlantic hurricane activity (PDI) due to 21st century greenhouse warming, the alternative statistical relationship between the PDI and the relative SST measure shown in the lower panel of Figure 1 would imply only modest future long-term trends of Atlantic hurricane activity (PDI) with greenhouse warming. In the latter case, the alternative relative SST measure in the lower panel does not change very much over the 21st century, even with substantial Atlantic warming projections from climate models, because, crucially, the warming projected for the tropical Atlantic in the models is not very different from that projected for the tropics as a whole.

A key question then is: Which of the two future Atlantic hurricane scenarios inferred from the statistical relations in Figure 1 is more likely? To try to gain insight on this question, we have first attempted to go beyond the ~50 year historical record of Atlantic hurricanes and SST to examine even longer records of Atlantic tropical storm activity and second to examine dynamical models of Atlantic hurricane activity under global warming conditions. These separate approaches are discussed below.

B. Analysis of century-scale Atlantic tropical storm and hurricane records

To gain more insight on this problem, we have attempted to analyze much longer (> 100 yr) records of Atlantic hurricane activity. If greenhouse warming causes a substantial increase in Atlantic hurricane activity, then the century scale increase in tropical Atlantic SSTs since the late 1800s should have produced a long-term rise in measures of Atlantic hurricanes activity, similar to that seen for global temperature, for example.

Existing records of past Atlantic tropical storm or hurricane numbers (1878 to present) in fact do show a pronounced upward trend, which is also correlated with rising SSTs (e.g., see blue curve in Fig. 4 or Vecchi and Knutson 2008). However, the density of reporting ship traffic over the Atlantic was relatively sparse during the early decades of this record, such that if storms from the modern era (post 1965) had hypothetically occurred during those earlier decades, a substantial number of storms would likely not have been directly observed by the ship-based “observing network of opportunity.” We find that, after adjusting for such an estimated number of missing storms, there remains just a small nominally positive upward trend in tropical storm occurrence from 1878-2006. Statistical tests indicate that this trend is not significantly distinguishable from zero (Figure 2). In addition, Landsea et al. (2010) note that the rising trend in Atlantic tropical storm counts is almost entirely due to increases in short-duration (<2 day) storms alone. Such short-lived storms were particularly likely to have been overlooked in the earlier parts of the record, as they would have had less opportunity for chance encounters with ship traffic.

If we instead consider Atlantic basin hurricanes, rather than all Atlantic tropical storms, the result is similar: the reported numbers of hurricanes were sufficiently high during the 1860s-1880s that again there is no significant positive trend in numbers beginning from that era (Figure 3, black curve, from CCSP 3.3 (2008)). This is without any adjustment for “missing hurricanes”.

The evidence for an upward trend is even weaker if we look at U.S. landfalling hurricanes, which even show a slight negative trend beginning from 1900 or from the late 1800s (Figure 3, blue curve). Hurricane landfalling frequency is much less common than basin-wide occurrence, meaning that the U.S. landfalling hurricane record, while more reliable than the basin-wide record, suffers from degraded signal-to-noise characteristics for assessing trends.

While major hurricanes (Figure 3, red curve) show more evidence of a rising trend from the late 1800s, the major hurricane data are considered even less reliable than the other two records in the early parts of the record. Category 4-5 hurricanes show a pronounced increase since the mid-1940s (Bender et al., 2010) but again, we consider that these data need to be carefully assessed for data inhomogeneity problems before such trends can be accepted as reliable.

The situation for various long-term Atlantic hurricane records and related indices is summarized in Figure 4. While global mean temperature and tropical Atlantic SSTs show pronounced and statistically significant warming trends (green curves), the U.S. landfalling hurricane record (orange curve) shows no significant increase or decrease. The unadjusted hurricane count record (blue curve) shows a significant increase in Atlantic hurricanes since the early 1900s. However, when adjusted with an estimate of storms that stayed at sea and were likely “missed” in the pre-satellite era, there is no longer any significant increase in Atlantic hurricanes since the late 1800s (red curve). While there have been increases in U.S. landfalling hurricanes and basin-wide hurricane counts since the since the early 1970s, Figure 4 shows that these recent increases are not representative of the behavior seen in the century long records. In short, the historical Atlantic hurricane record does not provide compelling evidence for a substantial greenhouse warming-induced long-term increase.

There is medium confidence for a detectable human contribution to past observed increases in heavy precipitation in general over global land regions with adequate coverage for analysis (e.g., IPCC AR5) and over the United States (Easterling et al. 2017), although an anthropogenic influence has not been formally detected for hurricane precipitation alone.  Several recent studies (e.g., van Oldenborgh et al. 2017; Risser and Wehner 2017) have concluded that Hurricane Harvey’s (2017) extreme rainfall totals, though primarily due to the storm’s slow movement over eastern Texas, were likely enhanced by anthropogenic warming.  Physically, a warmer atmosphere holds more water vapor that can enhance moisture convergence and rainfall rates in storm systems such as hurricanes.  The statistical analyses in these Hurricane Harvey studies focused on extreme precipitation in general, to which hurricanes contributed, but were not analyses of extreme rainfall only from hurricanes.

C. Model simulations of greenhouse warming influence on Atlantic hurricanes

Direct model simulations of hurricane activity under climate change scenarios offer another perspective on the problem. We have developed a regional dynamical downscaling model for Atlantic hurricanes and tested it by comparing with observed hurricane activity since 1980. This model, when forced with observed sea surface temperatures and atmospheric conditions, can reproduce the observed rise in hurricane counts between 1980 and 2012, along with much of the interannual variability (Figure 5). Animations showing the development and evolution of hurricane activity in the model are available here.

Turning to future climate projections, current climate models suggest that tropical Atlantic SSTs will warm dramatically during the 21st century, and that upper tropospheric temperatures will warm even more than SSTs. Furthermore, most of the CMIP3 models project increasing levels of vertical wind shear over parts of the western tropical Atlantic (see Vecchi and Soden 2007). Both the increased warming of the upper troposphere relative to the surface and the increased vertical wind shear are detrimental factors for hurricane development and intensification, while warmer SSTs favor development and intensification. To explore which effect of these effects might “win out”, we can run experiments with our regional downscaling model.

Our regional model projects that Atlantic hurricane and tropical storms are substantially reduced in number, for the average 21st century climate change projected by current models, but have higher rainfall rates, particularly near the storm center. The average intensity of the storms that do occur increases by a few percent (Figure 6), in general agreement with previous studies using other relatively high resolution models, as well as with hurricane potential intensity theory (Emanuel 1987).

Knutson and Tuleya (2004) estimated the rough order of magnitude of the sensitivity of hurricanes to climate warming to be about 4 percent per deg C SST warming for maximum intensities and about 12 percent per deg C for near-storm (100 km radius) rainfall rates (see also Knutson and Tuleya (2008) abstract here). Such sensitivity estimates have considerable uncertainty, as a subsequent assessment of multiple studies (Knutson et al. 2010) projected total increases by 2100 of about 2-11 percent for tropical cyclone intensity, and roughly 20 percent for near-storm rainfall rates.  Our more recent late 21st century projections of hurricane activity continue to support the notion of increased intensity (~ 4 percent) and near-storm rainfall rates (~ 10 to 15 percent) for the Atlantic basin (Knutson et al. 2013)  as well as for most other tropical cyclone  basins (Knutson et al. 2015). Wright et al. (2015) found model-projected increases in rainfall rates for U.S. landfalling tropical cyclones using this modeling system.

A review of existing studies, including the ones cited above, lead us to conclude that:

“It is likely that greenhouse warming will cause hurricanes in the coming century to be more intense globally and have higher rainfall rates than present-day hurricanes.”

climate change policy

Turning now to the question of the frequency of very intense hurricanes, the regional model of Knutson et al. (2008) has an important limitation in that it does not simulate such very intense hurricanes. For example, the maximum surface wind in the simulated hurricanes from that model is less than 50 m/s (which is borderline category 3 hurricane intensity). Furthermore, the idealized study of Knutson and Tuleya (2004) assumed the existence of hurricanes and then simulated how intense they would become. Thus, that study could not address the important question of the frequency of intense hurricanes.

In a series of Atlantic basin-specific dynamical downscaling studies (Bender et al. 2010Knutson et al. 2013), we attempted to address both of these limitations by letting the Atlantic basin regional model of Knutson et al. (2008) provide the overall storm frequency information, and then downscaling each individual storm from the regional model study into the GFDL hurricane prediction system. The GFDL hurricane model (with a grid spacing as fine as 9 km) is able to simulate the frequency, intensity, and structure of the more intense hurricanes, such as category 3-5 storms, much more realistically than the regional (18 km grid) model.

Using this additional downscaling step, the GFDL hurricane model reproduces some important historical characteristics of very intense Atlantic hurricanes, including the wind speed distribution and the change of this distribution between active and inactive decadal periods of hurricane activity (Fig. 1 of Bender et al. 2010). The model also supports the notion of a substantial decrease (~25 percent) in the overall number of Atlantic hurricanes and tropical storms with projected 21st century climate warming. However, using the CMIP3 and CMIP5 multi-model climate projections, the hurricane model also projects that the lifetime maximum intensity of Atlantic hurricanes will increase by about 5 percent during the 21st century in general agreement with previous studies.

The Bender et al. (2010) study projected a significant increase (+90 percent) in the frequency of very intense (category 4 and 5) hurricanes using the CMIP3/A1B 18-model average climate change projection. Subsequent downscaled projections using CMIP5 multi-model scenarios (RCP4.5) as input (Knutson et al. 2013) still showed increases in category 4 and 5 storm frequency. However, these increases were only marginally significant for the early 21st century (+45%) or the late 21st century (+39 percent) CMIP5 scenarios (based on model versions GFDl and GFDN combined). That study also downscaled ten individual CMIP3 models in addition to the multi-model ensemble, and found that three of ten models produced a significant increase in category 4 and 5 storms, and four of the ten models produced at least a nominal decrease. While multi-model ensemble results are probably more reliable than individual model results, each of the individual model results can be viewed as at least plausible at this time.  Based on Knutson et al. (2013) and a survey of subsequent results by other modeling groups, at present we have only low confidence for an increase in category 4 and 5 storms in the Atlantic; confidence in an increase in category 4 and 5 storms is higher at the global scale (see below).

Returning to the issue of future projections of aggregate activity (PDI, as in Fig. 1), while there remains a lack of consensus among various studies on how Atlantic hurricane PDI will change, no model we have analyzed shows a sensitivity of Atlantic hurricane PDI to greenhouse warming as large as that implied by the observed Atlantic PDI/local SST relationship shown in Figures 1 (top panel). In other words, there is little evidence from current dynamical models that 21st century climate warming will lead to large (~300 percent) increases in tropical storm numbers, hurricane numbers, or PDI in the Atlantic. As noted above, there is some indication from high resolution models of substantial increases in the numbers of the most intense hurricanes even if the overall number of tropical storms or hurricanes decreases.

Finally, one can ask when a large increase in Category 4-5 hurricanes, as projected by our earlier Bender et al. (2010) study, would be expected to be detectable in the Atlantic hurricane records, if it occurred in the real world. Owing to the large interannual to decadal variability of SST and hurricane activity in the basin, Bender et al (2010) estimate that detection of an anthropogenic influence on intense hurricanes would not be expected for a number of decades, even assuming a large underlying increasing trend (+10 percent per decade) occurs. While there is a large rising trend since the mid 1940s in observed category 4-5 numbers in the Atlantic, our view is that these data are not reliable for trend calculations, until they have been further assessed for data homogeneity problems, such as those due to changing observing practices.

D. Other possible human influences on Atlantic hurricane climate

Apart from greenhouse warming, other human influences conceivably could have contributed to recent observed increases in Atlantic hurricanes. For example, Mann and Emanuel (2006) hypothesize that a reduction in aerosol-induced cooling over the Atlantic in recent decades may have contributed to the enhanced warming of the tropical North Atlantic, relative to global mean temperature. However, the cause or causes of the recent enhanced warming of the Atlantic, relative to other tropical basins, and its effect on Atlantic tropical cyclones, remains highly uncertain (e.g., Booth et al. 2012Zhang et al. 2013;Dunstone et al. 2013Villarini and Vecchi 2013). A number of anthropogenic and natural factors (e.g., aerosols, greenhouse gases, volcanic activity, solar variability, and internal climate variability) must be considered as potential contributors, and the science remains highly uncertain in these areas. IPCC AR5 concluded that there is medium confidence that reduced aerosol forcing contributed to the observed increase in Atlantic tropical cyclone activity since the 1970s, but does not state any estimate of the magnitude of contribution.  They also conclude that it remains uncertain whether there are any detectable changes in past tropical cyclone activity.

Sea level rise must also be considered as a way in which human-caused climate change can impact Atlantic hurricane climate–or at least the impacts of the hurricanes at the coast. The vulnerability of coastal regions to storm-surge flooding is expected to increase with future sea-level rise and coastal development, although this vulnerability will also depend upon future storm characteristics, as discussed above. All else equal, tropical cyclone surge levels should increase with sea level rise.  There are large ranges in the 21st century projections for both Atlantic hurricane characteristics and for the magnitude of regional sea level rise along the U.S. coastlines. However, according to the IPCC AR5, the average rate of global sea level rise over the 21st Century will very likely exceed that observed during 1971-2010 for a range of future emission scenarios.

E. Summary for Atlantic Hurricanes and Global Warming

In summary, neither our model projections for the 21st century nor our analyses of trends in Atlantic hurricane and tropical storm counts over the past 120+ yr support the notion that greenhouse gas-induced warming leads to large increases in either tropical storm or overall hurricane numbers in the Atlantic. While one of our modeling studies projects a large (~100 percent) increase in Atlantic category 4-5 hurricanes over the 21st century, we estimate that such an increase would not be detectable until the latter half of the century, and we still have only low confidence that such an increase will occur in the Atlantic basin, based on an updated survey of subsequent modeling studies by our and other groups.

Therefore, we conclude that despite statistical correlations between SST and Atlantic hurricane activity in recent decades, it is premature to conclude that human activity–and particularly greenhouse warming–has already caused a detectable change in Atlantic hurricane activity. (“Detectable” here means the change is large enough to be distinguishable from the variability due to natural causes.) However, human activity may have already caused some some changes that are not yet detectable due to the small magnitude of the changes or observation limitations, or are not yet confidently modeled (e.g., aerosol effects on regional climate).

We also conclude that it is likely that climate warming will cause Atlantic hurricanes in the coming century have higher rainfall rates than present-day hurricanes, and medium confidence that they will be more intense (higher peak winds and lower central pressures) on average. In our view, it is uncertain how the annual number of Atlantic tropical storms will change over the 21st century. All else equal, tropical cyclone surge levels should increase with sea level rise as projected for example by IPCC AR5. These assessment statements are intended to apply to climate warming of the type projected for the 21st century by prototype IPCC mid-range warming scenarios.

The relatively conservative confidence levels attached to our tropical cyclone projections, and the lack of a claim of detectable anthropogenic influence on tropical cyclones at this time contrasts with the situation for other climate metrics, such as global mean temperature. In the case of global mean surface temperature, the IPCC AR5 presents a strong body of scientific evidence that most of the global warming observed over the past half century is very likely due to human-caused greenhouse gas emissions.

Greener Cities

Global Tropical Cyclone Activity and Climate Warming

The main focus of this web page is on Atlantic hurricane activity and global warming. However, an important question concerns whether global warming has or will substantially affect tropical cyclone activity in other basins.

In terms of historical tropical cyclone activity, recent work (Kossin et al. 2014; see GFDL Research Highlight; Kossin et al. 2016) indicates that the latitude at which the maximum intensity of tropical cyclones occurs has expanded poleward globally in recent decades.  The poleward shift in the Northwest Pacific they conclude is unusual compared to expected variability from natural causes but consistent with general expectations of such a shift due to anthropogenic warming seen in climate model experiments.  The poleward shift has been found in both hemispheres, but is not seen in the Atlantic basin.  Human activities may have already caused other changes in tropical cyclone activity that are not yet detectable due to the small magnitude of these changes compared to estimated natural variability, or due to observational limitations.

For future projections, GFDL atmospheric modelers have developed global models capable of simulating many aspects of the seasonal and year-to-year variability of tropical cyclone frequency in a number of basins, using only historical sea surface temperatures as input. Examples of the performance of these models on historical data are provided on this web page.

Our 2015 study examines the impact of 21st-century projected climate changes (CMIP5, RCP4.5 scenario) on a number of tropical cyclone metrics, using the GFDL hurricane model to downscale storms in all basins from one of the lower resolution global atmospheric models mentioned above. Key findings from these experiments include: fewer tropical cyclones globally in a warmer late-twenty-first-century climate (Figure 8), but also an increase in average cyclone intensity, the number and occurrence days of very intense category 4 and 5 storms in most basins (Figure 9) and in tropical cyclone precipitation rates (Figure 10).

Based on our published results and as well as those of other modeling groups, we conclude that at the global scale:  a future increase in tropical cyclone precipitation rates is likely; an increase in tropical cyclone intensity is likely; an increase in very intense (category 4 and 5) tropical cyclones is more likely than not; and there is medium confidence in a decrease in the frequency of weaker tropical cyclones.  Existing studies suggest a tropical cyclone windspeed increase of about 1-10% and a tropical cyclone precipitation rate increase of about 10-15 percent for a moderate (2 degree Celsius) global warming scenario. These global projections are similar to the consensus findings from a review of earlier studies in the 2010 WMO assessment.  [There is already medium confidence for a detectable human contribution to past observed increases in heavy precipitation in general over global land regions and for the United States, although this increase has not been formally detected for hurricane precipitation alone.]

These global-scale changes are not necessarily projected to occur in all tropical cyclone basins. For example, our 2015 study projects an increase in tropical storm frequency in the Northeast Pacific and near Hawaii, and a decrease in category 4-5 storm days over much of the southern hemisphere basins and parts of the northwest Pacific basin–both at variance with the global-scale projected changes. These differences in responses between basins seem to be linked to how much SSTs increase in a given region compared to the tropical mean increase in SST. Basins that warm more than the tropical average tend to show larger increases in tropical cyclone activity for a number of metrics.

Our 2015 study simulations also project little change in the median size of tropical cyclones globally; the model  shows some skill at simulating the differences in average storm size between various basins in the present-day climate, lending some credibility to its future climate change projections of tropical cyclone size.

WMO Expert Team 2010 Assessment of Tropical Cyclones and Climate Change

Tropical Cyclones and Climate Change“, an assessment by a World Meteorological Organization Expert Team on Climate Change Impacts on Tropical Cyclones is now available. This assessment was published in Nature Geoscience (March 2010). For more information on the expert team, see this WMO web page.

This report assesses published research on “Tropical Cyclones and Climate Change” from the international scientific literature.

Early GFDL Research on Global Warming and Hurricanes

The strongest hurricanes in the present climate may be upstaged by even more intense hurricanes over the next century as the earth’s climate is warmed by increasing levels of greenhouse gases in the atmosphere. Although we cannot say at present whether more or fewer hurricanes will occur in the future with global warming, the hurricanes that do occur near the end of the 21st century are expected to be stronger and have significantly more intense rainfall than under present day climate conditions. This expectation (Figure 11) is based on an anticipated enhancement of energy available to the storms due to higher tropical sea surface temperatures.

The results shown in Figure 11 are based on a simulation study carried out by Thomas R. Knutson and Robert E. Tuleya at NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL). In this study hurricanes were simulated for a climate warming as projected to occur with a substantial build-up of atmospheric CO2. An increase of intensity of about one-half category on the Saffir-Simpson scale was simulated for an 80 year build-up of atmospheric CO2 at 1 percent/yr (compounded). For hurricane wind speeds, our model shows a sensitivity of about 4 percent per degree Celsius increase in tropical sea surface temperatures, with a larger percentage increase in near-storm rainfall.

Read The Full Story About Global Warming And Hurricanes

public affairs and public relations firm

Crossbow is an award-winning and record-setting communications firm. We are public affairs and public relations experts who influence public opinion, public policy and business decisions around the world. We’re helping stakeholders tackle some of the most urgent issues of our time. Our headquarters are in Denver, Colorado. We’re opening a new office in Phoenix, Arizona.

Insurance Companies Not Ignoring Climate Change

Climate Change Risks Spark New Types Of Insurance Policies

Coral reefs, mangroves and even some fish could soon have their own insurance policies as the industry seeks new ways to boost protection for those affected by the ocean changes wrought by climate change.

Warmer sea temperatures have led to more intense storms in the Atlantic Ocean, contributing to $320 billion in disaster losses from weather and climate-related events last year, according to the World Meteorological Organization. Only about a quarter of these were insured.

climate change and extreme weather

But despite high payouts, industry experts speaking at the Ocean Risk Summit in reinsurance hub Bermuda said so-called “ocean risk” – which encompasses storms and hurricanes as well as marine diseases and declines in fish stocks – can present opportunities for insurers if the risks are modeled correctly.

One way to increase coverage is to devise new financial instruments to insure “green infrastructure” – such as coral reefs, mangroves and salt marshes that act as natural barriers against storms and can reduce devastating losses on land.

“There is a new role for insurance companies in the context of development strategies for countries most vulnerable to ocean risk,” said Falk Niehörster, director of Climate Risk Innovations, a risk management consultancy.

Niehörster has urged the creation of new insurance products to cover the $1.5 trillion global “blue economy” including fisheries, marine transport and other sectors.

Mark Way, a former reinsurance official who helped Swiss Re implement a policy for dozens of kilometers of coral reef and beach in Mexico this year – a world first – said his charity was inundated with calls from other insurers after the concept was announced.

sustainable cities and climate change

“There’s a lot of capital looking for investment opportunities so there are incentives to find innovative new ways to provide cover,” Way, head of global coastal risk and resilience for The Nature Conservancy, told the Thomson Reuters Foundation on the sidelines of the summit last week.

Governments also have a keen interest in such insurance policies since they can reduce the human and infrastructure losses on land that devastated parts of the Caribbean last year. Kedrick Pickering, deputy premier of the British Virgin Islands, which was hit by Hurricane Irma last year, said reef insurance was something the country would consider.

The Mexican reef insurance model works by automatically triggering payouts once storm-force winds hit a certain level. The same concept theoretically could be applied to damage to fish stocks causes by El Niño, based on changes to water current. Payouts would go to fishermen in that case.

“There is a whole host of ideas and we are just scraping the surface,” Way said.

However, some risks – such as pollution and overfishing, which scientists say could contribute to the loss of as much as 90 percent of global reefs by 2050 – are not covered under the novel Mexican insurance model.

And many species that have an enormous value to ocean ecosystems, such as crucial oxygen-generating bacteria, do not have easily quantifiable benefits to humanity, so are difficult to insure.

“Insurance can’t solve all the problems and we need to be mindful of the blindspots,” said Rashid Sumaila, director of the fisheries economics research unit at the University of British Columbia Fisheries Centre.

But so far even clearly identified threats to established markets remain largely uninsured. The nearly $23 billion a year northeastern US fisheries market, which includes high-value species such as lobster, scallops and cod, is expected to suffer from rising sea temperatures but so far remains largely uninsured, for instance.

Experts say more data and research on the oceans, such as plans to map the ocean’s resources as well as an ambitious project to create an ocean risk index by the end of this year, may help provide the missing pieces for insurers.

“Insurers are already developing products in response to ocean risk but an index could accelerate and deepen their engagement,” said Robert Powell, a senior consultant with the Economist Intelligence Unit, which is formulating the risk index.

Creating insurance products for marine assets could also build incentives to protect them against threats, or at least the ones local communities can control, Way said.

“If you can make the case successfully that it’s worth investing in an insurance policy then why spend that money if you are going to kill the reef through nutrient run off or pollution?” he asked.

Still, conservationists say there is a limit to what insurance can do and other protection will have to come from regulation, such as reducing illegal fishing and implementing a UN goal to transform 10 percent of the world’s oceans into protected areas by 2020.

Another shortcoming is that insurers, who tend to offer policies on short time horizons, are only likely to be interested in providing coverage against ocean risks in milder global warming scenarios.

Under the Paris Agreement on climate change, countries aim to hold average global temperature risk to “well below” two degrees Celsius, with an aim of one and a half degrees. So far, however, inadequate global plans to cut emissions suggest temperatures could rise three degrees or more.

“At three-degrees [temperature increase] you are looking at a structural challenge for billions of people that creates a whole new level of economic and social challenges for which insurance may not have all the answers,” said Rowan Douglas, head of capital, science and policy practice at global advisory firm Willis Towers Watson.

public affairs and public relations firm

Crossbow Communications specializes in issue management and public affairs. It specializes in health and environmental issues, including deforestation, sustainable agriculture, and wildlife conservation. Greener Cities is our global initiative to promote sustainable, resilient and responsible cities of the future. 

White House Approves Report On Climate Change

Human Activities Causing Global Warming

The climate of the United States is strongly connected to the changing global climate. The statements below highlight past, current, and projected climate changes for the United States and the globe.

Global annually averaged surface air temperature has increased by about 1.8°F (1.0°C) over the last 115 years (1901–2016). This period is now the warmest in the history of modern civilization. The last few years have also seen record-breaking, climate-related weather extremes, and the last three years have been the warmest years on record for the globe. These trends are expected to continue over climate timescales.

trees a climate change solution

This assessment concludes, based on extensive evidence, that it is extremely likely that human activities, especially emissions of greenhouse gases and deforestation, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.

In addition to warming, many other aspects of global climate are changing, primarily in response to human activities. Thousands of studies conducted by researchers around the world have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; diminishing snow cover; shrinking sea ice; rising sea levels; ocean acidification; and increasing atmospheric water vapor.

climate change policy

For example, global average sea level has risen by about 7–8 inches since 1900, with almost half (about 3 inches) of that rise occurring since 1993. Human-caused climate change has made a substantial contribution to this rise since 1900, contributing to a rate of rise that is greater than during any preceding century in at least 2,800 years. Global sea level rise has already affected the United States; the incidence of daily tidal flooding is accelerating in more than 25 Atlantic and Gulf Coast cities.

Global average sea levels are expected to continue to rise—by at least several inches in the next 15 years and by 1–4 feet by 2100. A rise of as much as 8 feet by 2100 cannot be ruled out. Sea level rise will be higher than the global average on the East and Gulf Coasts of the United States.

Changes in the characteristics of extreme events are particularly important for human safety, infrastructure, agriculture, water quality and quantity, and natural ecosystems. Heavy rainfall is increasing in intensity and frequency across the United States and globally and is expected to continue to increase. The largest observed changes in the United States have occurred in the Northeast.

Heatwaves have become more frequent in the United States since the 1960s, while extreme cold temperatures and cold waves are less frequent. Recent record-setting hot years are projected to become common in the near future for the United States, as annual average temperatures continue to rise. Annual average temperature over the contiguous United States has increased by 1.8°F (1.0°C) for the period 1901–2016; over the next few decades (2021–2050), annual average temperatures are expected to rise by about 2.5°F for the United States, relative to the recent past (average from 1976–2005), under all plausible future climate scenarios.

The incidence of large forest fires in the western United States and Alaska has increased since the early 1980s and is projected to further increase in those regions as the climate changes, with profound changes to regional ecosystems.

water shortages and drought

Annual trends toward earlier spring melt and reduced snowpack are already affecting water resources in the western United States and these trends are expected to continue. Under higher scenarios, and assuming no change to current water resources management, chronic, long-duration hydrological drought is increasingly possible before the end of this century.

The magnitude of climate change beyond the next few decades will depend primarily on the amount of greenhouse gases (especially carbon dioxide) emitted globally. Without major reductions in emissions, the increase in annual average global temperature relative to preindustrial times could reach 9°F (5°C) or more by the end of this century. With significant reductions in emissions, the increase in annual average global temperature could be limited to 3.6°F (2°C) or less.

The global atmospheric carbon dioxide (CO2) concentration has now passed 400 parts per million (ppm), a level that last occurred about 3 million years ago, when both global average temperature and sea level were significantly higher than today. Continued growth in CO2 emissions over this century and beyond would lead to an atmospheric concentration not experienced in tens to hundreds of millions of years. There is broad consensus that the further and the faster the Earth system is pushed towards warming, the greater the risk of unanticipated changes and impacts, some of which are potentially large and irreversible.

The observed increase in carbon emissions over the past 15–20 years has been consistent with higher emissions pathways. In 2014 and 2015, emission growth rates slowed as economic growth became less carbon-intensive. Even if this slowing trend continues, however, it is not yet at a rate that would limit global average temperature change to well below 3.6°F (2°C) above pre-industrial levels.

New observations and new research have increased our understanding of past, current, and future climate change since the Third U.S. National Climate Assessment (NCA3) was published in May 2014. This Climate Science Special Report (CSSR) is designed to capture that new information and build on the existing body of science in order to summarize the current state of knowledge and provide the scientific foundation for the Fourth National Climate Assessment (NCA4).Since NCA3, stronger evidence has emerged for continuing, rapid, human-caused warming of the global atmosphere and ocean. This report concludes that “it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”The last few years have also seen record-breaking, climate-related weather extremes, the three warmest years on record for the globe, and continued decline in arctic sea ice. These trends are expected to continue in the future over climate (multidecadal) timescales. Significant advances have also been made in our understanding of extreme weather events and how they relate to increasing global temperatures and associated climate changes. Since 1980, the cost of extreme events for the United States has exceeded $1.1 trillion; therefore, better understanding of the frequency and severity of these events in the context of a changing climate is warranted.

climate change and extreme weather

Periodically taking stock of the current state of knowledge about climate change and putting new weather extremes, changes in sea ice, increases in ocean temperatures, and ocean acidification into context ensures that rigorous, scientifically-based information is available to inform dialogue and decisions at every level. This climate science report serves as the climate science foundation of the NCA4 and is generally intended for those who have a technical background in climate science.

This report discusses climate trends and findings at several scales: global, nationwide for the United States, and for ten specific U.S. regions (shown in Figure 1 in the Guide to the Report). A statement of scientific confidence also follows each point in the Executive Summary. The confidence scale is described in the Guide to the Report. At the end of the Executive Summary and in Chapter 1: Our Globally Changing Climate, there is also a summary box highlighting the most notable advances and topics since NCA3 and since the 2013 Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report.

Global and U.S. Temperatures Rising

Long-term temperature observations are among the most consistent and widespread evidence of a warming planet. Temperature (and, above all, its local averages and extremes) affects agricultural productivity, energy use, human health, water resources, infrastructure, natural ecosystems, and many other essential aspects of society and the natural environment. Recent data add to the weight of evidence for rapid global-scale warming, the dominance of human causes, and the expected continuation of increasing temperatures, including more record-setting extremes.

Click Here For The Entire Report On Global Warming

public affairs and public relations firm

Crossbow Communications is an international marketing and public affairs firm. It specializes in issue management and public affairs. It’s also promoting sustainable, resilient and livable cities. Please contact Gary Chandler at gary@crossbow1.com to join our network.

Hurricanes Add Momentum To Climate Conversation

Tensions Rising With Tides and Temperatures

Hurricanes Harvey, Irma and Maria have poured new fuel on the debate over man-made climate change. It’s unfortunate that there is even a debate at all. We are wasting critical time and resources as we seek to justify our overconsumption and our fascination with capitalizing on the misfortunes of others.

Houston will never be the same. Islands across the Florida Keys have been reduced to rubble. Puerto Rico is largely uninhabitable with lack of power, water and food. Residents of New York and New Jersey still haven’t recovered from hurricane Sandy. New Orleans is still suffering from the impacts of Katrina in 2005. Meanwhile, in the wake of each disaster comes the fraud and fleecing of innocent citizens in the danger zone and beyond.

climate change and extreme weather

Since global warming and climate change are beyond the grasp of the special interests and their disciples, let’s dissect the issue from a different perspective.

The issue really boils down to energy waste and air pollution. Those who deny global warming are blowing smoke up your skirt. They want you to think that air pollution is fertilizer. Without taxpayer subsidies of billions of dollars annually, free-market capitalism would drive energy policies and innovation vs. costly policies that promote inefficiency and waste (not to mention favoritism/fascism, which isn’t capitalism). Does that waste and market manipulation contribute to global warming?

Conduct an experiment. Turn on your car and close the garage. CO2 builds up in the atmosphere just like it does in your garage. CO2 kills people and the planet.

Add global deforestation to the equation and we are staring at an ecological disaster and a public health disaster (deforestation is like turning off the exhaust fan in your garage). So, is it a good idea to waste energy and our only God-given home? It’s simple math and common sense. Reverence might even offer us a compass.public affairs and public relations firm

Crossbow Communications specializes in issue management and public affairs. It specializes in health and environmental issues, including sustainable cities and communities. Please contact Gary Chandler at gary@crossbow1.com to join our network.

Climate Change The Top Threat In Chile

Climate Change Now Taught In Public Schools

Fernando Rojas is holding up a photograph of a pocket of countryside, between the Pacific Ocean and the Andes mountains, that has been his home, his livelihood, and his passion for all of his 74 years.

His picture shows a lake, brimming with water, in front of a range of hills that are silhouetted by the sun. In the foreground, by the water’s edge, there’s a small boat, ready to set sail. Next to that, there’s a wooden jetty, jutting out into the waves.

Chile drought and climate change

You would hardly know that this image, taken in Chile just a few years ago, is of the same depleted landscape on which Rojas is now standing, grim-faced, puzzled and — he says — full of sadness.

Most of the water has gone. The jetty is marooned in a sea of mud and grass. Beside it, there is a new wire fence, erected to keep out horses and cattle that are grazing on the lake’s bed. Some boats are still there, stored away under canvas.

What water is left in the lake is in the hazy distance — about half of a mile away, a languid puddle, less than 3 feet deep, fringed by weeds and white egrets.

The Laguna de Aculeo — as this lake’s known — used to be a favorite retreat for many of the 7 million citizens of Chile’s capital, Santiago, 45 miles to the north.

On weekends, they came to windsurf, sail and Jet Ski, and to enjoy the tranquility of a valley with almond orchards, vineyards, poplar groves and wood cabins. Before the water suddenly receded, lakeside villas sold for more than $500,000.

For much of his life, Rojas farmed around the lake, growing melons and corn. He says the lake, which depends entirely on rainfall, began to shrink about seven years ago, and “got lower and lower and lower.”

The lake was roughly four times the size of New York’s Central Park. Rojas used to motor across it in a small boat to buy groceries. That same journey is now a walk. Lakeside villa prices collapsed — “no one wants to buy them, if they are not beside the water,” he remarks — and so have parts of the local economy.

Local people are “suffering [because] they depend on the water,” says Claudio Mella, an orthopedic surgeon in Santiago, who owns one of the villas and has been coming to the lake with his family for 15 years. “We have a lot of good friends here, and many of them have some depression, some family problems.”

Among those dependent on the lake is Oriana Lopez, who’s 55. Her once-thriving windsurfing business has received no clients for about five years, she says. Her family is left “in penury,” and must survive on her 97-year-old father’s pension, plus whatever money her son can earn doing casual labor.

“It is pitiful to see the lake like this,” Lopez says, as her dogs romp across what used to be the lake’s bed. Many people have had to leave the area, because of the lack of jobs. She, however, will stay and struggle on.

“I was born and raised here,” she says tearfully, “I love this land.”

Chile has been through an unusually severe seven-year drought that hit the central and southern areas where most of its population of 17 million lives. The affected zone includes the Laguna de Aculeo.

“We have been calling it the mega-drought because it has been very extended in space and in time,” says Maisa Rojas, a climatologist from the University of Chile. “We have seen this before, but never so widespread.” Although there has been a recent increase in precipitation, scientists are not yet sure if the drought’s over.

climate change policy

Studies are now underway investigating ways of saving the lake. “If nothing is done, it is possible the lake will dry out in a couple of years. It’s on the edge,” says Felipe Martin, a leading hydrologist who used to head the commission that develops Chile’s water resource policy.

Martin is among those working on rescue plans. He says the lake lost some water after its aquifers were disrupted by Chile’s 2010 earthquake. But drought is a major factor, and he blames that on climate change.

For Chile, the possible impact of climate change has now become an issue of profound concern on numerous fronts, from melting glaciers to conflicts over water rights between big agricultural businesses and small farmers.

“There is nobody who has not been affected by climate change, directly or indirectly, here in Chile,” says Matias Asun, director of Greenpeace Chile.

Chile’s Environment Minister, Marcelo Mena, cites “temperature anomalies” of 2 degrees Celsius in parts of Chile, and says there is “no space for climate denial because we see climate change threatening us in multiple shapes.”

Mena points to a wave of disasters that has hit Chile recently, including deadly floods and landslides, and a giant “red tide” — when an algae bloom, fueled by unusually warm sea temperatures, wiped out millions of fish, including 20 percent of the salmon production.

Sao Palo drought and water crisis

In January — fed by drought conditions — the worst wildfires in Chile’s history ripped across the landscape, destroying more than 2,300 square miles, including large areas of forests, and threatening some of the country’s famous vineyards.

“When you see the desperation in people’s eyes, and when you see things that you haven’t seen before, that really makes you worry that this is really getting out of hand,” Mena says.

“And when you see that some people are trying to deny the climate science, then … you have to take your gloves off, and you have to be very blunt about the fact that we are facing a challenge that is like something we have never seen before.”

Mena says most Chileans now regard climate change as their greatest external threat.

Proving that Chile’s wave of catastrophes was caused by climate change is highly complex. You have to use modelling studies to show any given event would have not have happened, were it not for climate change, says climatologist Maisa Rojas.

“We haven’t done any attribution studies for this, so I cannot say event[s] wouldn’t have happened, if it weren’t for climate change,” she says. “But the climate context in which these events have occurred are very much what we’d expect from climate change.”

Chile’s government is introducing a range of measures to help the country adapt to hotter, drier conditions — for example, better water conservation and fire prevention methods, and creating green spaces to help cool urban areas. To further raise awareness, there will be mandatory climate change classes in Chile’s schools, from next year onward.

Chile’s also rapidly expanding its use of renewable sources, which are expected to generate at least 80 percent of its energy by 2050. More than half the electricity used to power Santiago’s subway system will soon come from the sun and the wind. The lion’s share of this will be generated by a giant solar plant in Chile’s Atacama Desert, using hundreds of thousands of solar panels covering an area the size of 370 football fields.

At the Laguna de Aculeo — the shrinking lake — residents wonder what they will do if the water never comes back.

Paulo Gutierrez quit a high-pressure job in information technology and telecoms in Santiago to move to the lake with his family in search of a more tranquil way of life. He set up a cafe and a bakery around the time the lake’s water levels first began to drop. He is now is considering buying land further south, and moving there.

Gutierrez has moved beyond the debate over whether climate change is real; he believes Chile must now focus on figuring out how to adapt to it.

“We already know this thing is true, because we are suffering,” he says. “Twenty years ago, it was a possibility. Right now, it’s a reality.”

Read the full story at Climate Change News

public affairs and public relations firm

Crossbow Communications is an international marketing and public affairs firm. It specializes in issue management and public affairs. It’s also promoting sustainable, resilient and livable cities. Please contact Gary Chandler at gary@crossbow1.com to join our network.

UNDP Launches Program For Green Cities

Cities A Massive Problem, Opportunity

By Helen Clark, Administrator of the United Nations Development Programme

On behalf of UNDP, welcome to the launch of the UNDP Sustainable Urbanization Strategy. As we meet here in Quito today for the Habitat III conference, we are also celebrating the International Day for Poverty Eradication.

greener cities conference

Many of the world’s poor now live in cities where the most pressing development challenges are found. In order to achieve the Sustainable Development Goals, we need to ensure that the urban poor are not left behind.

The New Urban Agenda, which is due to be adopted here at Habitat III, aims to ensure that the cities of today and tomorrow offer an inclusive and sustainable future for all. The UNDP Sustainable Urbanization Strategy lays out the support which UNDP as a global development organization can provide to help achieve that.

Around our world, people are moving to cities in very large numbers.  Cities are seen as places of opportunity and hope, where hard work and determination can transform lives.

UNDP has developed its sustainable urbanization strategy to support cities to deliver on the hopes of their citizens and to implement the New Urban Agenda.  Many people in cities, particularly young people, lack work and say they currently feel excluded from opportunities. For women and girls, cities can be dangerous places where they cannot walk in safety and may risk exploitation in dangerous and demeaning jobs.  Natural disasters – including those exacerbated by climate change – and conflict and citizen insecurity can turn back the clock on hard won development gains.

UNDP’s experiences of working in towns and cities around the world have shaped this first UNDP sustainable urbanization strategy, and will guide our efforts beyond Quito.  Allow me to share three of our lessons learned:

  1. For cities to be succeed, they need to meet the needs of all their residents. Truly dynamic cities make space for all, and serve the needs of all.  Inclusivity is one of the main principles of the 2030 Agenda for Sustainable Development in which UN Member States pledged to leave no one behind. The needs and aspirations of poor and marginalized people in the world’s cities must be addressed to fulfill that ambition.
  2. Cities must be resilient to natural and man-made disasters and crises. Urban areas are now home to more than half the world’s people, and they also host most of the world’s critical infrastructure, key development assets, political institutions, and major socio-economic architecture. If disasters and crises rock cities, the spillover effects are great. In the first half of 2016 alone, natural disasters caused US$71 billion in damages worldwide, with most economic loss concentrated in cities. Political instability and conflict also have major costs.
  3. Cities are at the forefront of the battle against climate change and environmental degradation. They produce more than seventy percent of the world’s greenhouse gas emissions, and use eighty per cent of the world’s energy. How cities grow and develop in the coming decades will play a significant part in determining whether the world can live within its planetary boundaries.

climate change policy

Delivering the sustainable, inclusive, and resilient cities of the future requires that we work together in partnership, as UNDP is committed to doing. Our partnerships are diverse:

  • Here in Ecuador, we have been part of the efforts to help local communities recover and rebuild in Manabí province following the 16 April earthquake this year.
  • In Soacha, Colombia, a town close to Bogota, UNDP and UNCHR have been working together on a programme called Building Sustainable Solutions. It supports the local municipality with land registration and title, promoting economic development with the support of the private sector, and with community and institutional strengthening.
  • In Ulaanbaatar, Mongolia, UNDP has worked with local community groups to improve access to municipal services.
  • In Bangladesh, UNDP has supported municipal leaders to improve the livelihoods of millions of urban dwellers through our large scale Urban Partnerships for Poverty Reduction programme.
  • Initiatives like these, taken to scale through partnerships and strong urban leadership, will be critical to implementing the New Urban Agenda and achieving the Sustainable Development Goals.

Helen Clark is the Administrator of the United Nations Development Programme. She also chairs the United Nations Development Group.

Are Cities Ready For The Next Major Hurricane

Coastal Cities Unprepared For Extreme Storms

By Nick Stockton, Wired

After the storm, after the flooding, after the investigations, the US came to realize that what happened to New Orleans on August 29, 2005 was not a natural disaster. The levee system built by the US Army Corps of Engineers had structural flaws, and those flaws were awaiting the right circumstances. In that way, what happened was all but inevitable.

sustainable cities and climate change

And just as the storm is not to blame, New Orleans is not unique in its vulnerability. The city endured a lot of scolding in the aftermath of Katrina, as if the storm was the climax to a parable about poor urban planning. Sure, the city sits below sea level, at the end of hurricane alley, and relies heavily on an elaborate (and delicate) system of infrastructure. But where the city’s geography is unique, its vulnerability is anything but. Just about every coastal city, state, or region is sitting on a similar confluence of catastrophic conditions. The seas are rising, a storm is coming, and critical infrastructure is dangerously exposed.

The basic math of carbon dioxide is pretty simple: Generally, as CO2 levels rise, the air will warm. Warmer air melts glaciers, which drip into the sea—even as the water itself warms, too. Both cause the oceans to rise. Even if the entire planet stopped emitting carbon dioxide, Earth would continue to suffer the effects of past emissions.

“We’ve got at least 30 years of inertia in terms of sea level rise,” says Trevor Houser, a Rhodium Group economist who studies climate risk. And even if the sea weren’t rising, the rate of urban growth will more than double the area of urban land at high flood risk, according to a study Global Environmental Change published earlier this year.

But the sea is rising, at about .13 of an inch per year, for the past 20 years. (It was rising before then, too, but at about half the rate for the preceding 80 years.) Another recent study calculated that the world should expect about 4 feet of sea level rise for every degree Fahrenheit the global average temperature rises. This puts nearly every coastal city, in every coastal state, in danger of floods. Climate Central has an extensive project looking at sea level risk, if you’re curious about your city’s risk.

Warm air also holds more moisture, and moisture holds more energy, hence stronger (though not necessarily more frequent) storms. Those storms combine with high sea levels to create a danger greater than the sum of their parts. In a combined flooding event, a severe storm traps a city between rainfall and surging seas. Higher sea levels cause rivers to back up, water tables to saturate, shorelines to shorten. Storms—which are likely to be stronger than before—have fewer options to run off, so they pool and flood. And America built its coastal civilization oblivious to their threat.

hurricane Katrina

Take Florida, the most climate-threatened swath of American soil. It’s low, flat, built on porous limestone, and hurricane prone. According to a new analysis by disaster insurance agency Karen Clark and Co., Florida has four of the 10 US cities most vulnerable to combined flooding events.

Florida, knowing its place in the world, has copious levees and seawalls. But the levees are there mostly to protect against the Everglades. The seawalls are about as good at breaking a hurricane as a hood ornament is at breaking the wind. And all of that infrastructure is of little use in the face of combined flooding events—the sea will simply come up from below. Miami flooded last year when the storm sewers backed up because the water table was too high to drain them.

The Sunshine State’s geography makes it an easy target for blame (not to mention hurricanes). But if there’s anything the US should have learned in the decade since Katrina, it’s that storms don’t always hit where you expect them—because, you know, Sandy. “Florida is definitely the most vulnerable place, but you also have places like Norfolk that are built on the coastal floodplain, and parts of New England where there is a lot of sunk infrastructure very close to the increasingly vulnerable coast,” says Houser. The pattern repeats itself all along the Atlantic coastal plain: Physical protections are largely insufficient to protect against a new class of climate threats.

And then, sometimes, that infrastructure falls apart entirely. Louisiana’s levees couldn’t have held off Katrina entirely, but it was their collapse, not the hurricane itself, that turned the Big Easy into a bathtub. “Some were improperly designed, some were improperly constructed, the rest were improperly maintained,” says Sandy Rosenthal, the director of Levees.org, an infrastructure watchdog group.

That same sentence could apply to key infrastructure nationwide. A lot of the country’s infrastructure—its bridges, transportation corridors, airports, seaports, water supply systems, electrical grids, flood control, and so one—were built poorly, hastily, or both. A lot of it is old and neglected. In a 2013 survey, the American Society of Civil Engineers gave US infrastructure a D+ grade.

“A lot of infrastructure went up in the midcentury,” says Solomon Hsiang, a UC Berkeley economist who studies public policy. “Now we’re reaching the end of the natural lifetime of that infrastructure, and we need to decide that we can no longer ride on all the investment that occurred 50 or 60 years ago.” Much of this stuff is directly vulnerable to climate change. Earlier this year, the Army Corps of Engineers released two surveys describing hundreds of dams and thousands of levees vulnerable to rising seas and stronger storms. Threats identified—but not yet remedied.

Sustainable City News via http://climatedesk.org/2015/08/no-one-is-ready-for-the-next-katrina/

Sao Paulo Water Crisis A Symptom Of Deforestation In Amazon

Another Symptom Of Amazon Destruction, Privatization

In Brazil’s biggest city, a record dry season and rising demand for water has led to a punishing drought. It has actually been raining quite heavily over the last few days around Sao Paulo but it has barely made a drop of difference because of climate change.

The main reservoir system that feeds this immense city is dangerously low, and it would take months of heavy rainfall for water levels to return to normal.

Sao Palo drought and water crisis
Is the Sao Palo drought and water crisis caused by Amazon deforestation? This is Sao Paulo’s supply of drinking water.

So how does a country that produces an estimated 12 percent of the world’s fresh water end up with a chronic shortage of this most essential resource – in its biggest and most economically important city?

It’s interesting to note that both the local state government and the federal government have been slow to acknowledge there is a crisis, despite overwhelming evidence to the contrary. That might have been a politically expedient position to take during the recent election campaign, when the shortage of water in Sao Paulo was a thorny political issue, but the apparent lack of urgency in the city and wider state now is worrying many.

At the main Cantareira reservoir system, which feeds much of this city’s insatiable demand for water, things have almost reached rock bottom. Huge pipes suck out what water remains as the reservoir dips below 10 percent of its usual capacity. The odd local villager wanders around the dry bed of the lake hoping for a temporary windfall as fish flounder in the few pools that remain.

Deforestation and drought in Brazil
Deforestation kills more than trees.

In the town of Itu, not far from the slowly diminishing reservoir, Gilberto Rodriguez and several of his neighbours wait patiently in line. All of them are carrying as many jerry cans, empty plastic drinks bottles or buckets as they can muster. For weeks now they’ve been filling up with water from this emergency well. Twice a day Gilberto heaves the full containers into his car and heads home.

Every other house on the short drive seems to have a homemade poster pinned to the gate or doorframe. The same message, or plea, is written on each one; “Itu pede Socorro” – “Itu needs help.” Gilberto and his wife almost break into a laugh when I suggest to them that, according to Sao Paulo’s state government, the situation is manageable and there’s no need for water rationing.

“There’s been no water in our pipes now for a month,” says Soraya. “It’s not as bad as this in every community but we’ve had water rationing here since February.”

The car-crash scenario of a record dry season coupled with the ever-increasing demand for resources from South America’s biggest city seems almost to have caught the state water authority, Sabesp, by surprise. The authority, in turn, is being widely criticized for failing to plan and is now trying to manage a crisis.

Deforestation kills entire  ecosystems
Deforestation kills entire ecosystems.

Home to some 20 million people, the sprawling city of Sao Paulo continues to grow. But the failure of city services and basic infrastructure to keep pace merely exacerbates the problems, in particular the dwindling supplies of clean water.

Open sewers mean that Sao Paulo’s rivers are completely polluted. They’re now part of the problem rather than, as should be in times of drought, part of the solution.

Maria Cecilia Brito is part of the umbrella organization Alliance for Waters, which is belatedly trying to raise public awareness about the chronic shortages.

“People here were brought up to believe that water was a resource that would never end,” Maria Cedilla explains. “We were taking more water from the sources than those sources were able to replenish through natural means.”

But now one of Brazil’s leading scientists is suggesting that the causes of the drought may be even more worrying for Brazil in the long run. Antonio Nobre is one of country’s most respected Earth scientists and climatologists. He argues there is enough evidence to say that continued deforestation in the Amazon and the almost complete disappearance of the Atlantic forest has drastically altered the climate.

“There is a hot dry air mass sitting down here [in Sao Paulo] like an elephant and nothing can move it,” says the eminent scientist, who divides his time between the southern city of Sao Jose dos Campos and the Amazon city of Manaus.

reforestation and climate change solution
Reforestation can help turn the tides of climate change. Our sister company is ready to help.

“That’s what we have learned – that the forests have an innate ability to import moisture and to cool down and to favor rain. If deforestation in the Amazon continues, Sao Paulo will probably dry up. If we don’t act now, we’re lost,” adds Mr Nobre, whose recent report on the plight of the Amazon caused a huge stir in scientific and political circles.

Water shortages have the potential to harm the economy too, and that’s where the politicians in Sao Paulo and Brasilia just might start to act. Sao Paulo is by far Brazil’s richest state – the engine of the country’s economic growth – but if water and electricity, generated by hydroelectric dams, start running out the consequences for the economy could be dire. At a car parts factory in the north of the city I meet businessman Mauricio Colin. His aluminium plant needs about 15,000 litres of water a day to operate at normal capacity. Mauricio is already having to buy in extra water. He is worried about future supplies.

“The authorities know exactly what’s needed,” says Mauricio, above the din of his round-the-clock operation. “They have to invest in basic infrastructure because, without water, there are companies here who won’t be able to produce anything.”

Thus far public protests against the water shortages have been small – but the potential for frustration and disruption is there. Sao Paulo’s Water Authority has now acknowledged that unless water levels recover there may be power cuts and more water rationing. Everyone is praying for more rain, hoping that it’s not too late to reverse the effects of climate change and drought.

Source: http://www.bbc.com/news/world-latin-america-29947965

Rising Temperatures Ahead In Cities Around The Globe

Thermal Momentum Will Change Life In Many Cities

If it feels hot to you now in the dog days of this summer, imagine a time when summertime Boston starts feeling like Miami and even Montana sizzles. Thanks to climate change, that day is coming by the end of the century, making it harder to avoid simmering temperatures.

climate change city temperatures
Climate changing city temperatures.

Summers in most of the U.S. are already warmer than they were in the 1970s. And climate models tell us that summers are going to keep getting hotter as greenhouse gas emissions continue. What will this warming feel like? Our new analysis of future summers illustrates just how dramatic warming is going to be by the end of this century if current emissions trends continue unabated.

For our Blistering Future Summers interactive we have projected summer high temperatures for the end of this century for 1,001 cities, and then showed which city in the U.S. — or elsewhere in the world, if we couldn’t find one here — is experiencing those temperatures today. We’ve highlighted several striking examples on the interactive, but make sure to explore and find how much hotter summers will likely be in your city.

By the end of the century, assuming the current emissions trends, Boston’s average summer high temperatures will be more than 10°F hotter than they are now, making it feel as balmy as North Miami Beach is today. Summers in Helena, Mont., will warm by nearly 12°F, making it feel like Riverside, Calif.

In fact, by the end of this century, summers in most of the 1,001 cities we analyzed will feel like summers now in Texas and Florida (in temperatures only, not humidity). And in Texas, most cities are going to feel like the hottest cities now in the Lone Star State, or will feel more like Phoenix and Gilbert in Arizona, among the hottest summer cities in the U.S. today.

In some cases, summers will warm so dramatically that their best comparison is to cities in the Middle East. Take Las Vegas, for example. Summer highs there are projected to average a scorching 111°F, which is what summer temperatures are like today in Riyadh, Saudi Arabia. And at 114°F°, living in Phoenix will feel like summering in sweltering Kuwait City.

On average, summer heat is projected to warm 7-10°F, though some cities will have summers 12°F warmer than they are now. As you explore the interactive, you’ll find that for cities in the Northwest, the Great Plains, the Midwest, and the Northeast, warming is best illustrated by a southward shift. In some cases, however, the shift is slightly northward and inland — for example, warming in coastal San Diego will make it feel like Lexington, Ky., — and represents more than a 6°F temperature increase.

This analysis only accounts for daytime summer heat — the hottest temperatures of the day, on average between June-August — and doesn’t incorporate humidity or dewpoint, both of which contribute to how uncomfortable summer heat can feel. This projected warming also assumes greenhouse gas emissions keep increasing through 2080, just as they have been for the past several decades.

Source: http://www.climatecentral.org/news/summer-temperatures-co2-emissions-1001-cities-16583

Climate Change Talks Convene In Yokohama

IPCC Preparing Report On Climate Change Impacts

Government representatives and scientists on Tuesday opened a five-day meeting of the Intergovernmental Panel on Climate Change (IPCC) to finalize a report assessing the impacts of climate change on human and natural systems, options for adaptation, and the interactions among climate changes, other stresses on societies, and opportunities for the future.

IPCC meeting in Yokohama
If today’s floods are just a warning shot, many cities and nations might need a bigger boat.

The meeting, the culmination of four years’ work by hundreds of experts who have volunteered their time and expertise to produce a comprehensive assessment, will approve the Summary for Policymakers of the second part of the IPCC’s Fifth Assessment Report, checking the text line by line. The meeting will also accept the full report, which besides the Summary for Policymakers consists of a Technical Summary and 30 chapters in two volumes.

This report, produced by the IPCC’s Working Group II, deals with impacts, adaptation, and vulnerability. It is part two of a four-part assessment. The first part, by Working Group I, dealing with the physical science basis of climate change, was finalized in September 2013. The Working Group III contribution, assessing mitigation of climate change, will be finalized in April. The Fifth Assessment Report will be completed by a Synthesis Report in October.

“The Working Group II author team assessed thousands of papers to produce a definitive report of the state of knowledge concerning climate-change impacts, adaptation, and vulnerability. Many hundreds of volunteers, in and beyond the author team, approached this work with dedication and deep expertise,” said Vicente Barros, Co-Chair of Working Group II.

The meeting, hosted by the Government of Japan, runs from 25 to 29 March 2014. The Summary for Policymakers is due to be released on Monday 31 March. The draft full report will also be released at the same time, with final publication online and as a two-book series a few months later. Volume I will cover issues sector by sector. Volume II will consider continental-scale regions.

“This report considers consequences of climate changes that have already occurred and the risks across a range of possible futures. It considers every region and many sectors, ranging from oceans to human security. The focus is as much on identifying effective responses as on understanding challenges,” said Chris Field, the other Co-Chair of Working Group II.

The report builds on the four previous assessment reports produced by the IPCC since it was established in 1988. Compared to past Working Group II reports, the Working Group II contribution to the Fifth Assessment Report assesses a substantially larger knowledge base of relevant scientific, technical and socio-economic literature, facilitating a comprehensive assessment across a broader set of topics and sectors.

Source: http://www.ipcc.ch/