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| Cyclone Phailin makes landfall in India earlier this month. Photo courtesy Save the Children, via European Commission/flickr. |
By Jane Lubchenco and
Thomas E. Lovejoy in The Daily Climate
We have been given a sobering glimpse into the speed of our changing climate and the vulnerabilities of our world. It turns out we must focus greater attention to the tropics, where so much of humanity and wildlife live, and to our oceans.
We have been given a sobering glimpse into the speed of our changing climate and the vulnerabilities of our world. It turns out we must focus greater attention to the tropics, where so much of humanity and wildlife live, and to our oceans.
A sophisticated analysis,
published in the premier scientific journal Nature by a team
of young scientists at the University of Hawaii, Manoa, shows that impacts of
climate change are already dramatic, with much more to come. While policymakers
posture, dither and deny, the unraveling has already begun.
Many changes will
continue in the years ahead, but we can slow them and buffer some of their
impacts – if we act.
Using as a baseline the observed temperatures our world has known since 1860, when records first became reliable, biologist Camilo Mora and his co-authors sought to determine when future temperatures will move beyond the bounds of historical ranges. Others have examined how average temperatures will change; the Mora team examined how the full range of temperatures is changing, compared to historic ranges.
They come to the
surprising conclusion that the tropics are particularly vulnerable. A shift out
of the observed range of temperatures is expected as soon as 2020. When that
happens, the coldest temperatures will be warmer than the hottest in the past.
The implications for people, food supplies and biodiversity are tremendous.
Into the unknown
Over the next three
decades, many of the rest of the world's ecosystems – the deserts and jungles,
the temperate zones, the polar regions – will likely move outside of
temperature ranges that have nurtured life as we know it.
Within 35 years or so,
most cities on earth will be living in a climate different from that upon which
we have built our societies and civilization.
Examining changes
other than temperature, the University of Hawaii team found that the oceans are
already outside the historic range of variability for acidity. Oceans today are
30 percent more acidic than 150 years ago. And life in oceans is already
showing signs of this stress.
Power to slow the changes
These findings and
forecasts are startling, but there is some good news: This analysis found that
if we reduce the amount of climate-altering emissions over the next few decades,
we have the power to slow these changes significantly.
These results do not
mean polar regions won't see significant shifts. Or that ecosystems won't prove
flexible or resilient. But we have every reason to expect these climate changes
will radically reorganize ecosystems, with unknown consequences to humanity.
As a professor of
marine biology at Oregon State University and former administrator of the
National Oceanic and Atmospheric Administration, and a professor of science and
public policy at George Mason University, we see in this study a powerful
message to citizens and policymakers alike: It's time to take action.
From debating to documenting
A year ago, James
Hansen, formerly of NASA, and his co-authors added a significant measure of
understanding by looking at observed weather extremes over the last 30 years,
particularly heat waves, compared to historical records. They found that we had
lived through an exponential increase in outside-the-norm heat waves globally.
This study by Mora and
his co-authors adds an important measure to our knowledge. We're beyond
debating the existence of climate change, and onto documenting and forecasting
how quickly it takes shape around us. Shouldn't we also be acting to slow the
changes and to be prepared for what has been set in motion?
Jane Lubchenco is former National Oceanic and Atmospheric
Administration Administrator and a professor of marine biology at Oregon State
University. Thomas E. Lovejoy is professor of science and public policy at
George Mason University. The Daily Climate is an independent news service covering
energy, the environment and climate change. Find us on Twitter @TheDailyClimate or email editor
Douglas Fischer at dfischer [at] DailyClimate.org
