— Is it just freakish weather or something more? Climate scientists suggest
that if you want a glimpse of some of the worst of global warming, take a
look at U.S. weather in recent weeks.
wildfires. Oppressive heat waves. Devastating droughts. Flooding from giant
deluges. And a powerful freak wind storm called a derecho.
These are the
kinds of extremes experts have predicted will come with climate change,
although it's far too early to say that is the cause. Nor will they say
global warming is the reason 3,215 daily high temperature records were set
in the month of June.
linking individual weather events to climate change takes intensive study,
complicated mathematics, computer models and lots of time. Sometimes it
isn't caused by global warming. Weather is always variable; freak things
And this weather
has been local. Europe, Asia and Africa aren't having similar disasters now,
although they've had their own extreme events in recent years.
But since at
least 1988, climate scientists have warned that climate change would bring,
in general, increased heat waves, more droughts, more sudden downpours, more
widespread wildfires and worsening storms. In the United States, those
extremes are happening here and now.
So far this
year, more than 2.1 million acres have burned in wildfires, more than 113
million people in the U.S. were in areas under extreme heat advisories last
Friday, two-thirds of the country is experiencing drought, and earlier in
June, deluges flooded Minnesota and Florida.
"This is what
global warming looks like at the regional or personal level," said Jonathan
Overpeck, professor of geosciences and atmospheric sciences at the
University of Arizona. "The extra heat increases the odds of worse heat
waves, droughts, storms and wildfire. This is certainly what I and many
other climate scientists have been warning about."
head of climate analysis at the National Center for Atmospheric Research in
fire-charred Colorado, said these are the very record-breaking conditions he
has said would happen, but many people wouldn't listen. So it's I
told-you-so time, he said.
As recently as
March, a special report an extreme events and disasters by the Nobel
Prize-winning Intergovernmental Panel on Climate Change warned of
"unprecedented extreme weather and climate events." Its lead author, Chris
Field of the Carnegie Institution and Stanford University, said Monday,
"It's really dramatic how many of the patterns that we've talked about as
the expression of the extremes are hitting the U.S. right now."
seeing really is a window into what global warming really looks like," said
Princeton University geosciences and international affairs professor Michael
Oppenheimer. "It looks like heat. It looks like fires. It looks like this
kind of environmental disasters."
that on Thursday. That was before the East Coast was hit with triple-digit
temperatures and before a derecho — a large, powerful and long-lasting
straight-line wind storm — blew from Chicago to Washington. The storm and
its aftermath killed more than 20 people and left millions without
electricity. Experts say it had energy readings five times that of normal
Fueled by the
record high heat, this was among the strongest of this type of storm in the
region in recent history, said research meteorologist Harold Brooks of the
National Severe Storm Laboratory in Norman, Okla. Scientists expect "non-tornadic
wind events" like this one and other thunderstorms to increase with climate
change because of the heat and instability, he said.
haven't happened only in the past week or two. The spring and winter in the
U.S. were the warmest on record and among the least snowy, setting the stage
for the weather extremes to come, scientists say.
Since Jan. 1,
the United States has set more than 40,000 hot temperature records, but
fewer than 6,000 cold temperature records, according to the National Oceanic
and Atmospheric Administration. Through most of last century, the U.S. used
to set cold and hot records evenly, but in the first decade of this century
America set two hot records for every cold one, said Jerry Meehl, a climate
extreme expert at the National Center for Atmospheric Research. This year
the ratio is about 7 hot to 1 cold. Some computer models say that ratio will
hit 20-to-1 by midcentury, Meehl said.
"In the future
you would expect larger, longer more intense heat waves and we've seen that
in the last few summers," NOAA Climate Monitoring chief Derek Arndt said.
heat, drought, early snowpack melt and beetles waking from hibernation early
to strip trees all combined to set the stage for the current unusual spread
of wildfires in the West, said University of Montana ecosystems professor
Steven Running, an expert on wildfires.
While at least
15 climate scientists told The Associated Press that this long hot U.S.
summer is consistent with what is to be expected in global warming, history
is full of such extremes, said John Christy at the University of Alabama in
Huntsville. He's a global warming skeptic who says, "The guilty party in my
view is Mother Nature."
But the vast
majority of mainstream climate scientists, such as Meehl, disagree: "This is
what global warming is like, and we'll see more of this as we go into the
Intergovernmental Panel on Climate Change report on extreme weather: