[D66] NYT: Climate Change Threatens the World’s Food Supply, United Nations Warns

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Climate Change Threatens the World’s Food Supply, United Nations Warns
By
Christopher Flavelle
nytimes.com
7 min
View Original

The world’s land and water resources are being exploited at
“unprecedented rates,” a new United Nations report warns, which combined
with climate change is putting dire pressure on the ability of humanity
to feed itself.

The report, prepared by more than 100 experts from 52 countries and
released in summary form in Geneva on Thursday, found that the window to
address the threat is closing rapidly. A half-billion people already
live in places turning into desert, and soil is being lost between 10
and 100 times faster than it is forming, according to the report.

Climate change will make those threats even worse, as floods, drought,
storms and other types of extreme weather threaten to disrupt, and over
time shrink, the global food supply. Already, more than 10 percent of
the world’s population remains undernourished, and some authors of the
report warned in interviews that food shortages could lead to an
increase in cross-border migration.

A particular danger is that food crises could develop on several
continents at once, said Cynthia Rosenzweig, a senior research scientist
at the NASA Goddard Institute for Space Studies and one of the lead
authors of the report. “The potential risk of multi-breadbasket failure
is increasing,” she said. “All of these things are happening at the same
time.”

The report also offered a measure of hope, laying out pathways to
addressing the looming food crisis, though they would require a major
re-evaluation of land use and agriculture worldwide as well as consumer
behavior. Proposals include increasing the productivity of land, wasting
less food and persuading more people to shift their diets away from
cattle and other types of meat.

“One of the important findings of our work is that there are a lot of
actions that we can take now. They’re available to us,” Dr. Rosenzweig
said. “But what some of these solutions do require is attention,
financial support, enabling environments.”

The summary was released Thursday by the Intergovernmental Panel on
Climate Change, an international group of scientists convened by the
United Nations that pulls together a wide range of existing research to
help governments understand climate change and make policy decisions.
The I.P.C.C. is writing a series of climate reports, including one last
year on the disastrous consequences if the planet’s temperature rises
just 1.5 degrees Celsius above its preindustrial levels, as well as an
upcoming report on the state of the world’s oceans.

Some authors also suggested that food shortages are likely to affect
poorer parts of the world far more than richer ones. That could increase
a flow of immigration that is already redefining politics in North
America, Europe and other parts of the world.

“People’s lives will be affected by a massive pressure for migration,”
said Pete Smith, a professor of plant and soil science at the University
of Aberdeen and one of the report’s lead authors. “People don’t stay and
die where they are. People migrate.”

Between 2010 and 2015 the number of migrants from El Salvador, Guatemala
and Honduras showing up at the United States’ border with Mexico
increased fivefold, coinciding with a dry period that left many with not
enough food and was so unusual that scientists suggested it bears the
signal of climate change.

Barring action on a sweeping scale, the report said, climate change will
accelerate the danger of severe food shortages. As a warming atmosphere
intensifies the world’s droughts, flooding, heat waves, wildfires and
other weather patterns, it is speeding up the rate of soil loss and land
degradation, the report concludes.

Higher concentrations of carbon dioxide in the atmosphere — a greenhouse
gas put there mainly by the burning of fossil fuels — will also reduce
food’s nutritional quality, even as rising temperatures cut crop yields
and harm livestock.

Those changes threaten to exceed the ability of the agriculture industry
to adapt.

In some cases, the report says, a changing climate is boosting food
production because, for example, warmer temperatures will mean greater
yields of some crops at higher latitudes. But on the whole, the report
finds that climate change is already hurting the availability of food
because of decreased yields and lost land from erosion, desertification
and rising seas, among other things.

Overall if emissions of greenhouse gases continue to rise, so will food
costs, according to the report, affecting people around the world.

“You’re sort of reaching a breaking point with land itself and its
ability to grow food and sustain us,” said Aditi Sen, a senior policy
adviser on climate change at Oxfam America, an antipoverty advocacy
organization.

In addition, the researchers said, even as climate change makes
agriculture more difficult, agriculture itself is also exacerbating
climate change.

The report said that activities such as draining wetlands — as has
happened in Indonesia and Malaysia to create palm oil plantations, for
example — is particularly damaging. When drained, peatlands, which store
between 530 and 694 billion tons of carbon dioxide globally, release
that carbon dioxide back into the atmosphere. Carbon dioxide is a major
greenhouse gas, trapping the sun’s heat and warming the planet. Every
2.5 acres of peatlands release the carbon dioxide equivalent of burning
6,000 gallons of gasoline.

And the emission of carbon dioxide continues long after the peatlands
are drained. Of the five gigatons of greenhouse gas emissions that are
released each year from deforestation and other land-use changes, “One
gigaton comes from the ongoing degradation of peatlands that are already
drained,” said Tim Searchinger, a senior fellow at the World Resources
Institute, an environmental think tank, who is familiar with the report.
(By comparison, the fossil fuel industry emitted about 37 gigatons of
carbon dioxide last year, according to the institute.)


Similarly, cattle are significant producers of methane, another powerful
greenhouse gas, and an increase in global demand for beef and other
meats has fueled their numbers and increased deforestation in critical
forest systems like the Amazon.

Since 1961 methane emissions from ruminant livestock, which includes
cows as well as sheep, buffalo and goats, have significantly increased,
according to the report. And each year, the amount of forested land that
is cleared — much of that propelled by demand for pasture land for
cattle — releases the emissions equivalent of driving 600 million cars.

Overall, the report says there is still time to address the threats by
making the food system more efficient. The authors urge changes in how
food is produced and distributed, including better soil management, crop
diversification and fewer restrictions on trade. They also call for
shifts in consumer behavior, noting that at least one-quarter of all
food worldwide is wasted.

But protecting the food supply and cutting greenhouse emissions can also
come into conflict with each other, forcing hard choices.

For instance, the widespread use of strategies such as bioenergy — like
growing corn to produce ethanol — could lead to the creation of new
deserts or other land degradation, the authors said. The same is true
for planting large numbers of trees (something often cited as a powerful
strategy to pull carbon dioxide out of the atmosphere), which can push
crops and livestock onto less productive land.

Planting as many trees as possible would reduce the amount of greenhouse
gases in the atmosphere by about nine gigatons each year, according to
Pamela McElwee, a professor of human ecology at Rutgers University and
one of the report’s lead authors. But it would also increase food prices
as much as 80 percent by 2050.

“We cannot plant trees to get ourselves out of the problem that we’re
in,” Dr. McElwee said. “The trade-offs that would keep us below 1.5
degrees, we’re not talking about them. We’re not ready to confront them
yet.”

Preventing global temperatures from rising more than 1.5 degrees Celsius
is likely to require both the widespread planting of trees as well as
“substantial” bioenergy to help reduce the use of fossil fuels, the
report finds. And if temperatures increase more than that, the pressure
on food production will increase as well, creating a vicious circle.

“Above 2 degrees of global warming there could be an increase of 100
million or more of the population at risk of hunger,” Edouard Davin, a
researcher at ETH Zurich and an author of the report, said by email. “We
need to act quickly.”
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The report also calls for institutional changes, including better access
to credit for farmers in developing countries and stronger property
rights. And for the first time, the I.P.C.C. cited indigenous people and
their knowledge of land stewardship as resources to be tapped.
“Agricultural practices that include indigenous and local knowledge can
contribute to overcoming the combined challenges of climate change, food
security, biodiversity conservation, and combating desertification and
land degradation,” the report’s authors wrote.

It comes at a time when indigenous people are currently under threat.
According to a report released this year by the nonprofit organization
Global Witness, which looks at the links between conflicts and
environmental resources, an average of three people were killed per week
defending their land in 2018, with more than half of them killed in
Latin America.

Overall, the report said that the longer policymakers wait, the harder
it will be to prevent a global crisis. “Acting now may avert or reduce
risks and losses, and generate benefits to society,” the authors wrote.
Waiting to cut emissions, on the other hand, risks “irreversible loss in
land ecosystem functions and services required for food, health,
habitable settlements and production.”