An
international scientific panel has found that climate change will
pose sharp risks to the world’s food supply in coming decades,
potentially reducing output and sending prices higher in a period
when global food demand is expected to
soar.
That finding is by far the starkest
warning that the United Nations-appointed group, the Intergovernmental Panel on Climate
Change, has ever issued regarding the food supply. Its
last report, in 2007, was more sanguine, essentially finding that
climatic warming and the rising level of carbon dioxide in the air
would boost agricultural production across large areas, though that
report did cite some risks.
The warning is
contained in a draft report that leaked on Friday. The document is
not final and not scheduled for release until after an editing
session in Yokohama, Japan in
March.
The draft report warns that sweeping
impacts from climate change are already being seen across the
planet, and that these are likely to intensify as human emissions
of greenhouse gases continue to
rise.
Echoing past findings, the draft report
points out that land ice is melting worldwide, leading to a rise of
the sea that is putting coastal communities at increased risk of
flooding. It describes a natural world in turmoil as plants and
animals attempt to migrate to escape rising temperatures, and warns
that many could go extinct. Saving a significant fraction of the
world’s biological diversity may require far more aggressive human
management of natural systems, the report
declares.
Efforts to adapt to climate change have
already begun in many countries, the report found; President Obama
on Friday signed an
executive order to step up such efforts in the United
States. But these efforts remain inadequate compared with the
risks, the report says, and far more intensive — and expensive —
adaptation plans are likely to be required in the
future.
The report found that it is not too
late for cuts in emissions to have a strong impact on the future
risks of climate change, though the costs would be incurred in the
next few decades and the main benefits would likely be seen in the
late 21st century and beyond.
The
Intergovernmental Panel on Climate Change is the principal
scientific body charged with reviewing and assessing climate
science, then issuing reports about the risks to the world’s
governments. Its main reports come out every five to six years. The
group won
the Nobel Peace Prize, along with Al Gore, in 2007 for
its efforts to alert the world to the
risks.
Hundreds of billions of dollars are
being spent every year to reduce emissions, in direct response to
past findings from the group, though many analysts have said these
efforts are so far inadequate to head off drastic climatic changes
later in the century.
On the food
supply, the new report finds that benefits from global warming may
be seen in some areas, such as northern lands that are now marginal
for food production. But it added that over all, climate change
could reduce agricultural output by as much as 2 percent per decade
for the rest of this century, compared with what output would be
without climate change.
During that
period, demand is expected to rise as much as 14 percent each
decade, the report found, as billions of people in developing
countries acquire the money to eat richer diets. Rising food prices
would likely hit the world’s poor hardest, as has already occurred
from sharp price increases of recent years — spikes caused to a
large extent by certain types of weather extremes, like severe heat
waves, that have been linked to climate
change.
The agricultural risks “are greatest
for tropical countries, given projected impacts that exceed
adaptive capacity and higher poverty rates compared with temperate
regions,” the draft report finds.
If the report
proves to be correct, global food demand might have to be met – if
it can be met – by putting new land into production. That could
entail chopping down large areas of forest, an action that would
only accelerate climate change by sending substantial amounts of
carbon dioxide into the air from the destruction of
trees.
The leak of the new draft occurred on a
blog hostile to the scientific
panel.
“It’s a work in progress,” said
Jonathan Lynn, a spokesman for the intergovernmental panel. “We
don’t have anything to say about the contents. It’s likely to
change.”
But in a brief interview, Mr. Lynn did
not dispute the authenticity of the document. In the Internet era,
the group’s efforts to keep its drafts secret are proving to be a
failure, and some of the scientists involved have called for a
drafting process open to the
public.
A report about the physical science of
climate change leaked in August, then underwent only modest changes
before its final release in Stockholm in late September. The new
report covers the impacts of climate change, efforts to adapt to
it, and the vulnerability of human and natural
systems.
A third report, analyzing potential
ways to limit the rise of greenhouse gases, is due for release in
Berlin in April.