Shared from the 2018-06-18 The Denver Post eEdition
“A different world” with global warming
By Seth Borenstein The Associated Press
David Goldman, The Associated Press
SALIDA» We were warned. ¶ On June 23, 1988, a sultry day in Washington, James Hansen told Congress and the world that global warming wasn’t approaching — it had already arrived. The testimony of the top NASA scientist, said Rice University historian Douglas Brinkley, was “the opening salvo of the age of climate change.”
Thirty years later, it’s clear that Hansen and other doomsayers were right. And the change has been sweeping.
Earth is noticeably hotter, the weather stormier and more extreme. Polar regions have lost billions of tons of ice; sea levels have been raised by trillions of gallons of water. Far more wildfires rage.
Over 30 years — the time period climate scientists often use in their studies in order to minimize natural weather variations — the world’s annual temperature has warmed nearly 1 degree F (0.54 degrees C), according to the National Oceanic and Atmospheric Administration. And the temperature in the United States has gone up even more — nearly 1.6 degrees.
“The biggest change over the last 30 years, which is most of my life, is that we’re no longer thinking just about the future,” said Kathie Dello, a climate scientist at Oregon State University in Corvallis. “Climate change is here, it’s now and it’s hitting us hard from all sides.”
Warming hasn’t been just global, it’s been all too local. According to an Associated Press statistical analysis of 30 years of weather, ice, fire, ocean, biological and other data, every single one of the 344 climate divisions in the Lower 48 states — NOAA groupings of counties with similar weather — has warmed significantly, as has each of 188 cities examined.
South central Colorado, which includes Salida, has warmed 2.3 degrees on average since 1988, among the warmest divisions in the contiguous United States.
When she was a little girl 30 years ago, winery marketing chief Jessica Shook used to cross country ski from her Salida doorstep in winter. It was that cold and there was that much snow. Now, she has to drive about 50 miles for snow that’s not on mountaintops, she said.
“T-shirt weather in January, that never used to happen when I was a child,” Shook said. When Buel Mattix bought his heating and cooling system company 15 years ago in Salida, he had maybe four air conditioning jobs a year. Now, he’s got a waiting list of 10 to 15 air conditioning jobs long and may not get to all of them.
And then there’s the effect on wildfires. Veteran Salida firefighter Mike Sugaski used to think a fire of 10,000 acres was big. Now, he fights fires 10 times as large.
“You kind of keep saying, ‘How can they get much worse?’ But they do,” said Sugaski, who was riding his mountain bike on what usually are ski trails in January this year.
In fact, wildfires in the United States now consume more than twice the acreage they did 30 years ago.
The statistics tracking climate change since 1988 are almost numbing. Since 1988, daily heat records have been broken more than 2.3 million times at weather stations across the nation, half a million times more than cold records were broken.
The AP interviewed more than 50 scientists who confirmed the depth and spread of warming.
Clara Deser, climate analysis chief at the National Center for Atmospheric Research, said that when dealing with 30-year time periods in smaller regions than continents or the globe as a whole, it would be unwise to say all the warming is man-made. Her studies show that in some places in North American local — though not most — natural weather variability could account for as much as half of warming.
But when you look at the globe as a whole, especially since 1970, nearly all the warming is man-made, said Zeke Hausfather of the independent science group Berkeley Earth. Without extra carbon dioxide and other greenhouse gases, he said, the Earth would be slightly cooling from a weakening sun. Numerous scientific studies and government reports calculate that greenhouse gases in the big picture account for more than 90 percent of post-industrial Earth’s warming.
Others cautioned that what might seem to be small increases in temperature should not be taken lightly.
“One or two degrees may not sound like much, but raising your thermostat by just that amount will make a noticeable effect on your comfort,” said Deke Arndt, NOAA’s climate monitoring chief in Asheville, N.C., which has warmed nearly 1.8 degrees in 30 years.
Arndt said average temperatures don’t tell the entire story: “It’s the extremes that these changes bring.”The nation’s extreme weather — flood-inducing downpours, extended droughts, heat waves and bitter cold and snow — has doubled in 30 years, according to a federal index.
The 14 costliest hurricanes in American history, adjusted for inflation, have hit since 1988, reflecting both growing coastal development and a span that included the most intense Atlantic storms on record.
Climate scientists point to the Arctic as the place where climate change is most noticeable with dramatic sea ice loss, a melting Greenland ice sheet, receding glaciers and thawing permafrost. The amount of Arctic sea ice in September, when it shrinks the most, fell by nearly one third since 1988.
“There is a new Arctic now because the Arctic ocean is now navigable” at times in the summer, said Mark Serreze, director of the National Snow and Ice Data Center.
The vast majority of glaciers around the world have shrunk. A NASA satellite that measures shifts in gravity calculated that Earth’s glaciers lost 279 billion tons of ice — nearly 67 trillion gallons of water — from 2002 to 2017. Ice sheets in Greenland and West Antarctica have also have shriveled, melting about 455 billion tons of ice into water, according to the NASA satellite.
And it is enough — coupled with all the other melting ice — to raise the level of the seas. Overall, NASA satellites have shown three inches of sea level rise (75 millimeters) in just the past 25 years.
With more than 70 percent of the Earth is covered by oceans, a 3-inch increase means about 6,500 cubic miles (27,150 cubic km) of extra water. That’s enough to cover the entire United States with water about 9 feet deep.
It’s a fitting metaphor for climate change, say scientists: We’re in deep, and getting deeper.
“Thirty years ago, we may have seen this coming as a train in the distance,” NOAA’s Arndt said. “The train is in our living room now.”