Warming threatens West, study says

A warming planet means a longer forest growing season for the Inland Northwest, but the timber industry won’t likely see much benefit.

The gains in tree growth are being accompanied by increasing drought and much, much bigger wildfires, said Steven Running, a University of Montana scientist and one of the lead authors of a detailed assessment on climate change released Monday.

The 67-page report presents the most close-up picture yet of how changes to the planet are altering the West, Running said, in an interview Tuesday from Missoula.

The report points to profound impacts on everything from tourism to salmon runs to hydropower.

“There’s very little idle speculation. This is really a very sober, conservative assessment of the latest science,” Running said. “Every sentence has been closely scrutinized.”

Earlier this month, the U.N. Intergovernmental Panel on Climate Change released a summary of global warming’s impacts. The panel includes some 2,500 scientists and experts from across the world. Monday’s report was issued by the same group but zeroes in on North America.

Running is one of eight lead authors for the North American chapter of the report. His focus was on ecological impacts of global warming.

To compile the report, Running reviewed an estimated 500 scientific papers. From these, he selected 50 studies that presented the most important evidence of changes under way. The resulting document was then reviewed three times by other scientists. Running joked that the process felt more like a legal cross-examination than science.

Some of the most dramatic impacts from the warming planet are being felt in mountainous regions of the West, Running said. These are the places where only a small bump in temperature can have huge reverberations downstream.

“The spring snowmelt starts two to four weeks earlier,” Running said. “The whole season is pushed forward. That really comes back to bite us by the end of summer when wildfires explode and rivers run dry.”

Below are some highlights from the summary:

Forests: Warmer winters are killing off fewer insect pests, including beetles, leading to increases in tree-killing epidemics. Along with losses from wildfire, the North American timber industry could lose between $1 billion and $2 billion by the end of the century.

Wildfires: The forested area that burned in the West from 1987 to 2003 is nearly seven times greater than the acreage burned during the previous 16 years. Last summer, the Idaho Panhandle saw its most severe fire season in a generation. According to the report: “A warming climate encourages wildfires through a longer summer period that dries fuels, promoting easier ignition and faster spread.”

Tourism: Unless snow-making equipment is used, “the ski season in western North America will likely shorten substantially,” according to the report. The snowmobiling industry, worth $27 billion, “is more vulnerable to climate change because it relies on natural snowfall.”

Fish: Salmon and trout, which need clean, cold water, will be among the species hardest hit. Pacific salmon stocks are already in steep decline and are expected to face more problems with less snowmelt flowing into rivers in late summer, according to the report.

Rivers: Stream flows across the Rockies have been declining at a rate of 2 percent per decade over the past 60 years, and this trend is only expected to worsen. Over the same period, increases in rain and declines in snow have been measured at 74 percent of weather stations in Western mountains, according to the report. Peak stream flows are also occurring from one week to a month earlier on average. Managing the already complicated Columbia River system will become tougher with less summer snowmelt, according to the report.

Running said interest has been high in the latest report. He’s currently in the midst of a weeklong, three-state speaking tour. His main hope is that politicians take the report seriously.

“The scientists will have done all we can do for society on this topic,” Running said. “Now it becomes the politicians’ turn.”

Running is so convinced the changes are taking place, he’s planning to invest in another apricot tree for his backyard in Missoula.

He first tried growing an apricot tree when he moved to the city 27 years ago.

“One tough winter took it out,” he said. “We don’t get tough winters anymore.”