From left:
Lake Mead, Nevada, reached historically low levels, remains from New Mexico’s
wildfire, part of road swept away by floods in Yellowstone. Composite: AP,
Reuters, Getty Images
‘Historic’ weather: why a cocktail of natural
disasters is battering the US
As the world heats up, weather events will increase
and overlap, testing the limits of nation’s resiliency and recovery
Gabrielle
Canon in Oakland
@GabrielleCanon
Sat 18 Jun
2022 06.00 BST
https://www.theguardian.com/us-news/2022/jun/17/compound-extremes-natural-disasters-us-west
Summer in
the American west is off to an explosive start, with extreme weather events
ravaging multiple states in recent weeks. In Montana, historic flooding
devastated communities and infrastructure in and around Yellowstone national
park and forced a rare closure. Further south, reservoirs sank to new lows,
triple-digit heatwaves left millions sweltering, and wildfires ripped through
Arizona, New Mexico, Alaska and California.
These
layered disasters offer a glimpse of what’s to come. As temperatures continue
to climb, extreme events will not just increase – they’re more likely to
overlap, causing more calamity and testing the limits of the nation’s
resilience and recovery.
“The US has
a certain amount of capacity to cope with extreme events,” said Dr Andrew
Hoell, a meteorologist for the National Oceanic and Atmospheric
Administration’s (Noaa) physical sciences laboratory, adding that capacity is
stretched when these events build on one another, either regionally or
sequentially.
Natural
disasters, from floods to droughts to wildfires, have always occurred in areas
across the west, and it will take time for scientists to study the precise
connections between events like the destruction in Yellowstone and the climate
crisis. But it is clear that, in a warming world, combinations of factors are
increasingly likely to align and turn routine events into a catastrophe.
So-called “compound extremes”, where a combination of contributing factors come
together, are on the rise, Hoell said.
With increasing global surface temperatures the
possibility of more droughts and increased intensity of storms will likely
occur,
US Geological Survey
A layering of dangerous realities
The flood
in Yellowstone was one such “compound extreme”.
Warming
weather flushed melting snow into the waterways as a deluge pelted the region,
dropping up to three months-worth of summer rain over the span of just a few
days, according to an accounting done by CNN. Researchers with the US
Geological Survey (USGS) and two universities had already sounded the alarm
that an event like this was increasingly likely, publishing a report last year
on how the climate crisis could threaten the park. Noting that average
temperatures could increase by up to 10 degrees in the coming decades, they
concluded that the region should expect intense dry conditions peppered with
dangerous downpours.
“With
increasing global surface temperatures the possibility of more droughts and
increased intensity of storms will likely occur,” USGS scientists wrote. “As
more water vapor is evaporated into the atmosphere it becomes fuel for more
powerful storms to develop.”
The moment
a house collapses into a river as major floods close Yellowstone national park
– video
The
unprecedented and sudden flooding earlier this week toppled telephone poles,
knocked over fences, wiped out roads and bridges, and threatened to cut off fresh
drinking water supplies to the state’s largest city, after officials in
Billings, Montana, were forced to shut down its water treatment plant.
“None of us
planned a 500-year flood event on the Yellowstone when we designed these
facilities,” said Debi Meling, the city’s public works director. Remarkably no
one was reported hurt or killed, but the damage has been possibly permanent and
recovery could take years.
“We
certainly know that climate change is causing more natural disasters, more
fires, bigger fires and more floods and bigger floods,” said Robert Manning, a
retired University of Vermont professor of environment and natural resources.
“These things are going to happen, and they’re going to happen probably a lot
more intensely.”
Loading the
dice for heatwaves and fire
Now in the
third year of deeply dry conditions, roughly 44% of the American west has been
categorized in extreme drought, according to the US drought monitor. Once-lush
hillsides have grown brown, waterways have receded into the cracked earth and
the agricultural, ecological and industrial impacts are expected to mount, and
swaths of the west will go without hope of precipitation through the summer and
into autumn.
That’s also
loaded the dice for wildfires, as blazes behave more erratically and grow
harder to battle. States in the south-west have been hammered by dozens of
conflagrations this spring, including a ferocious fire in New Mexico that
became the worst in the state’s history.
The number
of square miles burned so far this year is more than double the 10-year
national average, and wildfires have already set records and destroyed hundreds
of homes.
Destructive
fires, a devastating drought, and torrential floods are each catastrophes in
their own right – but when they overlap they are even more capable of causing
calamity. Scientists say these events are happening more frequently, and that
the climate crisis is a key culprit.
“These are
three events that are all extremely consistent with our baseline
well-understood expectations of climate change,” said Dr Karen McKinnon, a
climate scientist and professor at University of California Los Angeles. She
explains how, when the atmosphere warms, it holds on to more moisture. That
deepens drought conditions and sets the stage for stronger storms.
“The most basic
influence of us putting more greenhouse gasses in the atmosphere is
temperatures warming,” she said. “We can pretty confidently say going forward
that these types of events are just going to be more likely because
temperatures keep going up and up.”
What we are seeing is we are just going to be getting
more and more of these heatwaves breaking records because we are moving
temperatures toward warmer conditions
Karen McKinnon
While
extreme heat makes other weather events more dangerous, it’s also a deadly
threat on its own. Heatwaves have already taken a serious toll this year.
Millions of people across the US have faced sweltering springtime temperatures
that fail to drop at night, increasing the potential for harm to health. An
investigation by the LA Times published last year found that fatalities from
heat are abysmally undercounted in California, and that related deaths could be
as much as six times higher than the official tally.
“What we
are seeing is we are just going to be getting more and more of these heatwaves
breaking records because we are moving temperatures toward warmer conditions,”
McKinnon said. Scientists say heatwaves are also growing in size, affecting
entire regions with greater frequency. Roughly a third of Americans – more than
100 million people – had to grapple with dangerous temperatures as a heatwave
covered large swaths of the country last week.
‘Biggest
crisis facing our nation’, but can resources keep up?
Compounding
catastrophes have put strain on resources. From a severe shortage in
firefighters ahead of peak risk periods to difficulty reining in water-use,
agencies struggle to prepare for the worst effects. Patrick Roberts, a senior
political scientist at the Rand Corporation who studies disasters, says many
systems have gotten better at contending with simultaneous events but there’s
more work to be done.
“Covid gave
us the experience of a national emergency,” he said, noting that although the
pandemic has been dire, it helped streamline national systems that never had to
respond simultaneously to an event not confined to a geographical region.
Not
preparing comes at a high cost, both financially and in the devastation wreaked
on communities.
Every
dollar spent on hazard mitigation saves the US $6 in future disaster costs,
according to a study released in 2019 by the National Institute of Building
Sciences. Last year, the US spent an alarming $145bn on natural disasters – the
third highest amount on record – and grappled with 20 extreme events that cost
more than $1bn each, close to triple the average since 1980.
The fire is
still burning in the hills above the areas scorched by Sheep Fire in
California. Photograph: Étienne Laurent/EPA
The Federal
Emergency Management Agency (Fema) is already bracing for an escalation in need
this year and for the ones that follow, requesting $19.7bn for its 2023
disaster relief fund.
“The field
of emergency management is at a pivotal moment in its history,” Fema
administrator Deanne Criswell said during a hearing of the House homeland
security subcommittee on emergency preparedness, response and recovery. The
agency is managing more than triple the amount of disasters this year as it did
a decade ago.
“The
changing climate is the biggest crisis facing our nation and makes natural
disasters more frequent and more destructive,” Criswell said. “While our
mission itself has not changed, our operating environment has.”


Sem comentários:
Enviar um comentário