Washington Post
- Annabelle Timsit | Sarah Kaplan
Researchers used machine learning to analyze more than 100,000 studies of
weather events and found four-fifths of the world’s land area has suffered
impacts linked to global warming
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People ride in a cart pulled by zebus near Amboasary
Atsimo in Madagascar, an area that is suffering a food
crisis because of intense drought.
(Rijasolo/AFP/Getty Images)
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At least 85 percent of the global population has experienced
weather events made worse by climate change, according to
research published Monday in the journal Nature Climate Change.
After using machine learning to analyze and map more than 100,000
studies of events that could be linked to global warming,
researchers paired the analysis with a well-established data set of
temperature and precipitation shifts caused by fossil fuel use and
other sources of carbon emissions.
These combined findings — which focused on events such as crop
failures, floods and heat waves — allowed scientists to make a solid
link between
escalating extremes
and human activities. They concluded that global warming has
affected 80 percent of the world’s land area.
“We have a huge evidence base now that documents how climate change
is affecting our societies and our ecosystems,” said lead author Max
Callaghan, a researcher at the Mercator Research Institute on Global
Commons and Climate Change in Germany.
The study provides hard numbers to back up the lived experiences of
people from New York City to South Sudan. “Climate change,”
Callaghan said, “is visible and noticeable almost everywhere in the
world.”
The findings come amid a major push to get countries to commit to
more ambitious climate goals ahead of a United Nations summit in
Glasgow, Scotland, next month.
Research shows
that existing pledges will put the planet on track to heat up about
2.7 degrees Celsius (4.9 degrees Fahrenheit) by the end of the
century — a level of warming that would lead to drastic food and
water shortages, deadly weather disasters, and catastrophic
ecosystem collapse.
Some of the world’s top emitters, including China and India, have
yet to formally commit to a new 2030 emissions reduction target.
Activists worry that an emerging
energy crisis, which has raised prices and triggered blackouts, could imperil
efforts to get developing economies to phase out polluting fuels.
In the United States, climate disasters have already caused at least
388 deaths and more than $100 billion in damage this year, according
to analyses from
The Washington Post and the
National Oceanic and Atmospheric Administration.
Yet despite a pledge to halve emissions by the end of the decade,
congressional Democrats are struggling to pass a pair of bills that
would provide hundreds of billions of dollars for renewable energy,
electric vehicles and programs that would help communities adapt to
a changing climate.
The contrast between the scope of climate disasters and the scale of
global ambition is top of mind for
hundreds of protesters
who have descended on Washington this week to demand an end to
fossil fuel use.
“How can you say that we are in this climate emergency and be going
around and saying we’re at this red point … and at the same time be
giving away land for additional oil and gas infrastructure?” said
Joye Braun, a community organizer with the Indigenous Environmental
Network and a member of the Cheyenne River Sioux Tribe
who
rallied in Washington this week.
The activists, many of them from Indigenous communities that have
been harmed by global warming, risked arrest as they remained on the
sidewalk outside the White House after police ordered them to clear
the area.
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A U.S. Park Police officer looks on as people take part
in a climate change protest outside the White House on
Oct. 11. (Evelyn Hockstein/Reuters)
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The new research in Nature adds to a growing body of evidence that
climate change is already disrupting human life on a global scale.
Scientists are increasingly able to attribute events like heat waves
and hurricanes to human actions. In August, the U.N.
Intergovernmental Panel on Climate Change devoted an entire chapter
to the extreme weather consequences of a warming world.
The study’s conclusion that 85 percent of humanity is experiencing
climate impacts may sound high. But it’s “probably an
underestimation,” said Friederike Otto, a senior lecturer at the
Grantham Institute for Climate Change and the Environment at
Imperial College London, who was not involved in the study.
The study looked at average temperature and precipitation changes,
rather than the most extreme impacts, for which Otto says there is
even more evidence of climate change’s role.
“It is likely that nearly everyone in the world now experiences
changes in extreme weather as a result of human greenhouse gas
emissions,” she said.
The human toll of these events has become impossible to ignore. This
summer, hundreds of people in the Pacific Northwest died after
unprecedented heat
baked the usually temperate region. More than 1 million people in
Madagascar are at risk of starvation as a historic drought morphs
into a climate-induced famine. Catastrophic flooding caused New
Yorkers to drown in their own homes, while flash flooding has
inundated refugee camps in South Sudan.
In a letter released Monday, some 450 organizations representing 45
million health-care workers called attention to the way rising
temperatures have increased the risk of many health issues,
including breathing problems, mental illness and insect-borne
diseases. One of the papers analyzed for the Nature study, for
example, found that deaths from heart disease had risen in areas
experiencing hotter conditions.
“The climate crisis is the single biggest health threat facing
humanity,” the health organizations’
letter
said.
Yet in many of the places that stand to suffer most from climate
change, Callaghan and his colleagues found a deficit of research on
what temperature and precipitation shifts could mean for people’s
daily lives.
The researchers identified fewer than
10,000 studies looking at climate change’s effect on Africa, and
about half as many focused on South America. By contrast, roughly
30,000 published papers examined climate impacts in North America.
In poorer countries, the researchers say, roughly a quarter of
people live in areas where there have been few impact studies,
despite strong evidence that they are experiencing changes in
temperature and precipitation patterns. In wealthier countries, that
figure stands at only 3 percent.
“But it indicates that we’re not studying enough,” Callaghan said,
“not that there isn’t anything happening.”
Otto attributes this discrepancy, known as an “attribution gap,” to
a lack of capacity and funding for research in poor countries, as
well as researchers’ tendency to reflect the priorities of wealthy
nations.
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A protective wall is erected with reclaimed sand in
Guraidhoo, Maldives, on Oct. 10. The Maldives is one of
the world's lowest-lying countries, making it extremely
vulnerable to climate change.
(Allison Joyce/Getty Images)
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In South Sudan, for example, efforts to understand flooding have
been stymied by conflict and the difficulty of collecting weather
data in the world’s youngest country.
Liz Stephens, an associate professor in climate risks and resilience
at the University of Reading, wrote in an email that the Global
Flood Awareness System from the Copernicus Emergency Management
Service is “notoriously bad” at forecasting flooding in the White
Nile and Blue Nile river basins.
Without good data,
scientists can’t easily say what places are likely to be deluged or
warn when a disaster is about to hit. Officials may be caught off
guard by weather events. Vulnerable people are less able to get out
of harm’s way.
South Sudanese officials say half a million people — about 4 percent
of the country’s population — have been displaced by the floods.
But the “attribution gap” makes machine-learning-based analyses like
Callaghan’s all the more valuable, Otto said. These programs can
help identify climate impacts even in places where there are not
enough scientists studying them.
“It seems a very useful way … to understand better what climate
change is costing us today in a global way that is more bottom-up,”
Otto said.
Here in the nation’s capital, policymakers are still debating the
costs of moving away from fossil fuels.
While members of both parties back a
nearly $1 trillion infrastructure bill that has passed the Senate and would provide $7.5 billion to build
out a national network of electric-vehicle charging stations and
several other measures to cut carbon emissions, the White House is
struggling to muster enough support for a $3.5 trillion bill that
would provide incentives for utilities that get an increasing share
of their power from solar, wind and other carbon-free sources and
penalize those that don’t move swiftly enough.
According to a
recent analysis
by the Rhodium Group, an independent research firm, the
larger spending bill would curb U.S. greenhouse gas emissions
by as much as a gigaton — but would probably get the country only
halfway to its 2030 goals.
A September
study
in Nature found that 60 percent of Earth’s oil and fossil methane
gas and 90 percent of coal must remain in the ground for the world
to have a chance of limiting warming to 1.5 degrees Celsius (2.7
degrees Fahrenheit) — a threshold that scientists say would spare
humanity the most disastrous climate impacts.
Increasingly, groups are calling on President Biden to restrict
fossil fuel production outright.
On Wednesday, a coalition of more than 380 groups filed
a legal petition
demanding that the U.S. Army Corps of Engineers stop issuing permits
for new fossil fuel infrastructure projects. Two days later,
hundreds of scientists submitted an
open letter
asking Biden to do the same.
“The reality of our situation is now so dire that only a rapid
phase-out of fossil fuel extraction and combustion can fend off the
worst consequences of the climate crisis,” they wrote.
In response to Monday’s protests, however, American Petroleum
Institute spokeswoman Megan Bloomgren said curbing the country’s
energy options would harm the economy and national security.
“American energy is produced under some of the highest environmental
standards in the world,” she said.
Pledging to reduce greenhouse gas emissions without cutting back on
fossil fuel extraction, activists say, is like a person promising to
lose weight while continuing to consume french fries and doughnuts.
“It’s the only way the pledges make sense,” said Dharini
Parthasarathy, senior communications officer for policy at the
Climate Action Network. “Otherwise, they’re just promises.”
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