Climate Change Will Force Us to Abandon Coastal Cities.
We'd Better Start Preparing Right Now
former climate chief for NASA warns that future sea
level rises could leave many if not all of the world's
coastal cities "dysfunctional."
Hansen, in a paper set for publication in the journal
Atmospheric Chemistry and Physics Discussion, says that
even if the world manages to attain the goal of limiting
global warming to 2 degrees Celsius, sea level rises
could still be dangerous for humanity.
shows average temperatures just a single degree warmer
than today caused extreme storms thousands of years ago
and caused sea level rises as high as 16 to 30 feet,
Hansen and his study co-authors say.
is the biggest threat the planet faces," Hansen
says. "If we get sea level rise of several meters,
all coastal cities become dysfunctional. The
implications of this are just incalculable."
the last major interglacial period 120,000 years ago,
global temperatures were also 2 degrees warmer than our
preindustrial climate levels and sea levels reached
levels that could wreak havoc today, he says.
cities threatened by sea level rises would be major U.S.
cities including Boston, New York, Seattle and Miami,
the researchers say. They also note it would be
difficult to protect low-lying areas such as Bangladesh,
European lowlands, and large portions of the United
States' eastern coast and northeast China plains against
such large increases in the sea level.
say they base their projection of sea level rise on an
expected acceleration in the melting of ice sheet
coverings in Antarctica and Greenland, driven by warming
resulting in increased concentration of atmospheric
greenhouse gases from ongoing burning of fossil fuels.
from the melting ice sheets flowing into the world's
oceans could change their circulation patterns, which in
turn could result in even faster melting and a rise in
sea levels greater than has been put forward in previous
forecasts, the study authors say.
"We conclude that continued high emissions
will make multimeter sea level rise practically
unavoidable and likely to occur this century," they
wrote. "Social disruption and economic consequences
of such large sea level rise could be devastating."
Hansen headed NASA's Goddard Institute for Space Studies
until 2013 and is now with Columbia University's
Department of Earth and Environmental Sciences.
social and economic cost of the world's coastal cities
becoming dysfunctional as a result of sea level rise
would be devastating, he says. It is a possible future
if we don't manage to mitigate the effects of climate
change, he warns.
think that the major implication of that will be that we
hand young people a climate system where it's not
possible to avoid a large sea level rise," he says.