New York Times - John Schwartz
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| A seaside neighborhood in Mexico Beach, Fla., devastated by Hurricane Michael this year. Credit Scott Olson/Getty Images |
Global warming is posing such
wide-ranging risks to humanity, involving so many types of phenomena,
that by the end of this century some parts of the world could face as
many as six climate-related crises at the same time, researchers say.
This chilling prospect is described in a paper
published Monday in Nature Climate Change, a respected academic journal, that shows the effects of climate change across a broad spectrum of problems, including heat waves, wildfires, sea level rise, hurricanes, flooding, drought and shortages of clean water.
Such
problems are already coming in combination, said the lead author,
Camilo Mora of the University of Hawaii at Manoa. He noted that Florida
had recently experienced extreme drought, record high temperatures and
wildfires — and also Hurricane Michael, the powerful Category 4 storm
that
slammed into the Panhandle last month. Similarly, California is suffering through
the worst wildfires the state has ever seen, as well as drought, extreme heat waves and degraded air quality that
threatens the health of residents.
Things will get worse, the authors wrote. The paper projects future trends
and suggests that, by 2100, unless humanity takes forceful action to
curb the greenhouse gas emissions that drive climate change, some
tropical coastal areas of the planet, like the Atlantic coast of South
and Central America, could be hit by as many as six crises at a time.
That prospect is “like a terror movie that is real,” Dr. Mora said.
The
authors include a list of caveats about the research: Since it is a
review of papers, it will reflect some of the potential biases of
science in this area, which include the possibility that scientists
might focus on negative effects more than positive ones; there is also a
margin of uncertainty involved in discerning the imprint of climate
change from natural variability.
New York can expect to be hit by four climate crises at a time by 2100 if carbon emissions continue at their current pace, the study says, but if emissions are cut significantly that number could be reduced to one. The troubled regions of the coastal tropics could see their number of concurrent hazards reduced from six to three.
The
paper explores the ways that climate change intensifies hazards and
describes the interconnected nature of such crises. Greenhouse gas
emissions, by warming the atmosphere, can enhance drought in places that
are normally dry, “ripening conditions for wildfires and heat waves,”
the researchers say. In wetter areas, a warmer atmosphere retains more
moisture and strengthens downpours, while higher sea levels increase
storm surge and warmer ocean waters can contribute to the overall
destructiveness of storms.
New York can expect to be hit by four climate crises at a time by 2100 if carbon emissions continue at their current pace, the study says, but if emissions are cut significantly that number could be reduced to one. The troubled regions of the coastal tropics could see their number of concurrent hazards reduced from six to three.
The
paper explores the ways that climate change intensifies hazards and
describes the interconnected nature of such crises. Greenhouse gas
emissions, by warming the atmosphere, can enhance drought in places that
are normally dry, “ripening conditions for wildfires and heat waves,”
the researchers say. In wetter areas, a warmer atmosphere retains more
moisture and strengthens downpours, while higher sea levels increase
storm surge and warmer ocean waters can contribute to the overall
destructiveness of storms.
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| A
search-and-rescue team looking for human remains in the aftermath of
the recent Camp Fire in Paradise, Calif. The state is also suffering
from drought, extreme heat waves and degraded air quality. Credit Eric Thayer for The New York Times |
In a scientific world marked by specialization and siloed research, this
multidisciplinary effort by 23 authors reviewed more than 3,000 papers
on various effects of climate change. The authors determined 467 ways in
which those changes in climate affect human physical and mental health,
food security, water availability, infrastructure and other facets of
life on Earth.
The paper
concludes that traditional research into one element of climate change
and its effects can miss the bigger picture of interrelation and risk.
Climate
change also has different ramifications for the world’s haves and
have-nots, the authors found: “The largest losses of human life during
extreme climatic events occurred in developing nations, whereas
developed nations commonly face a high economic burden of damages and
requirements for adaptation.”
People
are not generally attuned to dealing with problems like climate change,
Dr. Mora said. “We as humans don’t feel the pain of people who are far
away or far into the future,” he said. “We normally care about people
who are close to us or that are impacting us, or things that will happen
tomorrow.”
And so, he said, people
tend to look at events far in the future and tell themselves, “We can
deal with these things later, we have more pressing problems now.” But,
he added, this research “documented how bad this already is.”
The paper includes an
interactive map
of the various hazards under different emissions scenarios for any
location in the world, produced by Esri, which develops geographic
information systems. “We see that climate change is literally redrawing
the lines on the map, and revealing the threats that our world faces at
every level,” said Dawn Wright, the company’s chief scientist.
Michael
E. Mann, a climate scientist at Pennsylvania State University who was
not involved in the paper, said it underscored the urgency for action to
curb the effects of climate change and showed that “the costs of
inaction greatly outweigh the costs of taking action.”
Dr. Mann published
a recent paper
suggesting that climate change effects on the jet stream are
contributing to a range of extreme summer weather events, such as heat
waves in North America, Europe and Asia, wildfires in California and
flooding in Japan. The new study, he said, dovetails with that research,
and “is, if anything, overly conservative” — that is, it may
underestimate the threats and costs associated with human-caused climate
change.
A co-author of the new paper, Kerry
Emanuel of the Massachusetts Institute of Technology, hailed its
interdisciplinary approach. “There’s more than one kind of risk out
there,” he said, but scientists tend to focus on their area of research.
“Nations, societies in general, have to deal with multiple hazards, and
it’s important to put the whole picture together.”
Like
military leaders developing the capability to fight wars on more than
one front, governments have to be ready to face more than one climate
crisis at a time, Dr. Emanuel said.
Dr.
Mora said he had considered writing a book or a movie that would
reflect the frightening results of the research. His working title,
which describes how dire the situation is for humanity, is unprintable here. His alternate title, he said, is “We Told You So.”
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