UM climate expert says triple-digit Julys will be norm

UM climate expert says triple-digit Julys will be norm


HELENA - The blistering heat of this past July will be the norm in less than 50 years if global warming continues as expected, a University of Montana ecologist and climate expert predicts.

Steve Running, a UM forestry professor who was one of the authors of a seminal international paper on climate change released this spring, said forecasts predict an average July in 2050 will be like the withering, record-breaking July of 2007 - with triple digit temperatures common.

"You can imagine that, little by little, over the next five decades it will become more and more common to have months like we had in July," he said. "That doesn't mean we're not going to have some colder months and some wetter months in July. But it's going to be more common to have those kinds of temperatures and in 50 years it will be the average."

Fires to be more common

In addition to the heat, Running said another factor of this summer will likely become more common: forest fires.

Running said climate change is driving forest fires in a number of ways and urged both federal and state lawmakers to set aside money to battle wildfire as big, summertime burns are likely to be with us for a long time.

July was a record-breaking month all over the state: Miles City set four record highs and hit 110 degrees twice. Glendive reported 111 degrees twice - the hottest temperature ever recorded in Montana on those dates, according to the National Weather Service. Temperatures soared above 100 degrees for almost two solid weeks in Glendive.

Billings slugged through 22 days of above-90 degree temperatures, with eight days above 100 degrees. Temperatures there broke two records: a record high for July 6 of 104 degrees and for 10 straight days the nighttime lows did not dip below 65 degrees.

In Helena, July 2007 ranks as the hottest July on record, according to the National Weather Service. The mercury climbed above 90 for 28 days in July and inched above 100 degrees on eight days, both setting records for sustained heat.

Missoula also set a record high, 107 degrees, and endured a record-setting 11 days above 100 degrees.

All told, July 6 was likely the hottest day in Montana history, according to the National Weather Service, with highs in the state's largest cities averaging 102 degrees that day. Some sort of heat-related record was set on 23 days in July, the agency reports.

The climate forecasts are based on the presumption that global warming doesn't occur faster than is happening right now, he said, and there's some indication that the world's output of carbon dioxide - the main ingredient behind global warming - is increasing, rather than staying the same. More carbon dioxide could accelerate the warming, he said.

On the flip side, the warming is not set in stone. If humanity could cut its output of carbon dioxide, the warming could be remarkably slowed, he said.

"We think that if we could cut the top off of carbon emissions in the next couple of decades, temperatures that we'll see 50 years from now will be measurably different" than the dire forecasts of today, he said.

Burning fossil fuels like coal, oil and gasoline will create carbon dioxide.

Even if all carbon emissions stopped today, Running said, it is not likely that global warming would be reversed. Climate is tied to the temperature of the oceans and the earth's oceans now have already absorbed enough heat to throw off climate for another 20 years or so, Running said.

He said global warming is driving the wildfires that have blackened hundreds of thousands of acres in Montana this year.

"We used to have a bad fire year maybe once every ten or 20 years," he said. "We've now had four of them since 2000."

In addition to hotter, drier conditions, global warming also creates longer, drier summers which leads to worsening infestations of pine bark beetles, Running said. Beetle infestations only add to the wildfire danger.

It's not just global warming driving the fire seasons, he said. Decades of putting out wildfires has resulted in thicker forests which burn more easily. But fire suppression alone doesn't explain the explosive fire seasons of late and it doesn't negate the role that global warming plays.

Running said some logging could improve things. Right now, logging is less common than it used to be and forests are growing more timber than the land can support. Careful selective thinning would reduce those trees and make the forests healthier, thus reducing the threat of wildfire.

"Clear cutting is a different story," he said. "But thinning and selective logging has kept forests within the carrying capacity."

He said it's "crazy" not to set money aside for battling wildfires. Neither the state nor the federal government specifically budget for wildfire.

"Year in and year out, we're probably going to have expenses in the 30 to 40 to 50 million a year range," he said. "There's more houses built in the woods and it is getting warmer and drier."


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