By: weather.com
Published: March 31,2014
A planet warmed by human-produced greenhouse gases poses significant
risks already to people, cities and nations today and not just in the
far-off future, according to a report the
Intergovernmental Panel on Climate Change released Monday.
And those risks could mean "
abrupt or drastic changes"
that could lead to unstoppable and irreversible climate shifts like the
runaway melting of Greenland's glacial ice or the rapid drying out of
South America's Amazon rainforest, the Christian Science Monitor
reports.
The dangers of a warming Earth aren't limited to animals like polar bears. They're immediate and very human, the report says.
"The
polar bear is us," says Patricia Romero Lankao of the federally
financed National Center for Atmospheric Research in Boulder, Colo.,
referring to the first species to be listed as threatened by global
warming due to melting sea ice.
She was among the more than 60 scientists in Japan who wrote the
massive and authoritative report on the impacts of global warming, the
second of three installments in the IPCC's latest assessment on the
world's climate.
Another author offer of the report offered this
assessment Monday: "We're all sitting ducks," said Princeton University
professor Michael Oppenheimer.
After several days of late-night
wrangling, more than 100 governments unanimously approved the
scientist-written 49-page summary — which is aimed at world political
leaders. The summary mentions the word "risk" an average of about 5 1/2
times per page.
(MORE: Climate Change Threatens Food Supply)
If climate change continues, the panel's larger report predicts these harms:
Violence: For
the first time, the panel is emphasizing the nuanced link between
conflict and warming temperatures. Participating scientists say warming
won't cause wars, but it will add a destabilizing factor that will make
existing threats worse.
Food: Global food prices
will rise between 3 and 84 percent by 2050 because of warmer
temperatures and changes in rain patterns. Hotspots of hunger may emerge
in cities.
Water: About one-third of the world's
population will see groundwater supplies drop by more than 10 percent
by 2080, when compared with 1980 levels. For every degree of warming,
more of the world will have significantly less water available.
Health:
Major increases in health problems are likely, with more illnesses and
injury from heat waves and fires and more food and water-borne diseases.
But the report also notes that warming's effects on health is
relatively small compared with other problems, like poverty.
Wealth: Many
of the poor will get poorer. Economic growth and poverty reduction will
slow down. If temperatures rise high enough, the world's overall income
may start to go down, by as much as 2 percent, but that's difficult to
forecast.
The report says scientists have already observed many
changes from warming, such as an increase in heat waves in North
America, Europe, Africa and Asia. Severe floods, such as the one that
displaced 90,000 people in Mozambique in 2008, are now more common in
Africa and Australia.
(MORE: Scientists: Let's Change How We Talk About Climate Change)
Europe
and North America are getting more intense downpours that can be
damaging. Melting ice in the Arctic is not only affecting the polar
bear, but already changing the culture and livelihoods of indigenous
people in northern Canada.
Past panel reports have been ignored
because global warming's effects seemed too distant in time and
location, says Pennsylvania State University scientist Michael Mann.
This
report finds "It's not far-off in the future and it's not exotic
creatures — it's us and now," says Mann, who didn't work on this latest
report.
The United Nations established the climate change panel in
1988 and its work is done by three groups. One looks at the science
behind global warming. The group meeting in Japan beginning Tuesday
studies its impacts. And a third looks at ways to slow warming.
Its
reports have reiterated what nearly every major scientific organization
has said: The burning of coal, oil and gas is producing an increasing
amount of heat-trapping greenhouse gases, such as carbon dioxide. Those
gases change Earth's climate, bringing warmer temperatures and more
extreme weather, and the problem is worsening.
The panel won the Nobel Peace Prize in 2007, months after it issued its last report.
Since
then, the impact group has been reviewing the latest research and
writing 30 chapters on warming's effects and regional impacts. Those
chapters haven't been officially released but were posted on a skeptical
website.
(MORE: Feel Like Spring Arrives Earlier Than It Used To?)
The key message can be summed up in one word that the overall report uses more than 5,000 times: risk.
"Climate
change really is a challenge in managing risks," says the report's
chief author, Chris Field of the Carnegie Institution of Science in
California. "It's very clear that we are not prepared for the kind of
events we're seeing."
Already the effects of global warming are
"widespread and consequential," says one part of the larger report,
noting that science has compiled more evidence and done much more
research since the last report in 2007.
According to the report,
risks from warming-related extreme weather, now at a moderate level, are
likely to get worse with just a bit more warming. While it doesn't say
climate change caused the events, the report cites droughts in northern
Mexico and the south-central United States, and hurricanes such as
2012's Sandy, as illustrations of how vulnerable people are to weather
extremes. It does say the deadly European heat wave in 2003 was made
more likely because of global warming.
Texas Tech University
climate scientist Katharine Hayhoe, who was not part of this report
team, says the important nuance is how climate change interacts with
other human problems: "It's interacting and exacerbating problems we
already have today."
University of Colorado science policy
professor Roger Pielke Jr., a past critic of the panel's impact reports,
said after reading the draft summary, "it's a lot of important work ...
They made vast improvements to the quality of their assessments."
(MORE: Earth's Carbon Dioxide Levels Reach New Heights)
Another
critic, University of Alabama Huntsville professor John Christy,
accepts man-made global warming but thinks its risks are overblown when
compared with something like poverty. Climate change is not among the
developing world's main problems, he says.
But other scientists
say Christy is misguided. Earlier this month, the world's largest
scientific organization, the American Association for the Advancement of
Science, published a new fact sheet on global warming.
It said:
"Climate change is already happening. More heat waves, greater sea level
rise and other changes with consequences for human health, natural
ecosystems and agriculture are already occurring in the United States
and worldwide. These problems are very likely to become worse over the
next 10 to 20 years and beyond."
Texas Tech's Hayhoe says
scientists in the past may have created the impression that the main
reason to care about climate change was its impact on the environment.
"We care about it because it's going to affect nearly every aspect of human life on this planet," she says.
Information from the Associated Press was used in this report.
MORE: The World's Most Historic Places in 2,000 Years
Above, we used Google Earth to visualize what
15 of the sites in the study might look like in the future, if its sea
level rise projections come to pass. Thanks to Andrew David Thaler's
DrownYourTown for the template to create these visualizations. (Photo by
Bob Collowân/Wikimedia Commons)
