you’re planning to build that dream beach house along the East Coast of the United States, or would like to relocate to the Caribbean, a new study by economists and climate
scientists suggests you may want to reconsider.
from the Massachusetts Institute of Technology (MIT) and Yale University have
found that coastal regions of North America and the Caribbean, as well as East
Asia, are most at risk for hurricane damage—a finding that may not surprise
residents of such hurricane-prone communities. However, the researchers say by
the year 2100, two factors could more than quadruple the economic damages
caused by tropical storms in such regions and around the world: Growing income
and global warming.
a paper published in Nature Climate Change, researchers developed a model
to predict hurricanes around the world, looking at how hurricane activity might
change in the next 100 years both with and without climate change.
in a world without climate change, where rates of greenhouse gas emissions
remain stable, the researchers found that annual economic damages from
hurricanes could double in the next century: Global population is expected to
reach 9 billion by 2100, likely leading to more development along
hurricane-prone coastlines. Given such growth, the researchers projected that
worldwide annual damage from hurricanes—currently $26 billion—could increase to
$56 billion in the next century.
a similar economic scenario, but with the added factor of climate change, the
team found that annual hurricane damage could quadruple to $109 billion by
2100. According to the researchers’ model, proliferating greenhouse gases would
likely increase the incidence of severe tropical cyclones and hurricanes, which
would increase storm-related damage.
the researchers found that the distribution of damage is not even across the
world. Their model indicates that climate change would cause the most
hurricane-related damage in North America, followed by East Asia, Central
America, and the Caribbean. The rest of the world—particularly
the Middle East, Europ,e and South America—would remain relatively unscathed,
experiencing little to no hurricane activity.
Treading new territory
Kerry Emanuel, the Cecil and Ida Green Professor of Atmospheric Science at MIT,
says results from the model developed by the team may have wide-ranging
implications for regional planning and emergency preparedness.
could be used by lots of different people … to understand what resources to put
into certain countries to mitigate or adapt to tropical cyclone changes
resulting from climate change,” says Emanuel, a co-author of the paper. “For
example, urban planners in cities might want to know how high to make the flood
barriers if sea levels go up.”
worked with researchers at Yale to develop the hurricane prediction model, an
effort that combined two disparate disciplines: atmospheric modeling and
economics. Emanuel describes the work as “treading new territory,” and the
researchers had to “do a lot of back and forth to understand each other’s
sorting out semantics, the group set out to predict tropical cyclone and
hurricane activity around the world. The researchers relied on four existing
climate models commonly used by the Intergovernmental Panel on Climate Change
to assess climate risks. Each of the models track and forecast certain climate
variables such as wind, temperature, large-scale ocean currents, and ocean
temperatures. However, the models only track these variables at a relatively
coarse resolution of 100 to 200 km. Since a tropical cyclone that may whip into
a massive hurricane under certain weather conditions requires resolutions of a
few kilometers, using climate models to simulate storms is highly problematic.
Seeds of a cyclone
Instead, Emanuel and his colleagues embedded a tropical-cyclone model within
each climate model. The combination allowed the team to see where storms may
develop around the world, based on regional weather systems. The researchers
randomly scattered hundreds of thousands of “seeds,” or potential tropical
cyclones, throughout each of the four models, then ran the models to see where
the seeds developed into significant storms. There was some variation between
models, but in general, they revealed that 95% of storms simply dissipate,
leaving 5% that were likely to turn into hurricanes under favorable conditions
such as warm ocean water and high winds. They used enough seeds to generate
17,000 surviving storms in each simulation.
team also looked at each country’s hurricane-related damage after adjusting for
its gross domestic product (GDP). The researchers found that wealthier nations
like the United States are
able to absorb economic losses from a hurricane better than many others, such
as island nations in the Caribbean.
are all small islands, and most of their GDPs are exposed,” Emanuel says. “In
the United States,
you take all this damage and divide it by the GDP of the whole country, and you
get a smaller relative impact.”
researchers stress that there was a fair amount of uncertainty in predictions
made among the four climate models. For example, in estimating the effect of
climate change on tropical-cyclone damage, the models’ predictions ranged from $14
billion to $80 billion a year.
also points out that “looking at natural disasters strictly through an economic
lens doesn’t tell you the whole story.” For example, despite a growing economy
and population, if severe tropical cyclones become more frequent, people may
choose to build elsewhere—a phenomenon Emanuel says an improved model will have
to take into account.