WASHINGTON — In November, just after winning re-election, President Barack Obama identified dealing with climate change as one of the top three priorities for his second term, which begins today.

“I am a firm believer that climate change is real, that it is impacted by human behavior and carbon emissions. And as a consequence, I think we’ve got an obligation to future generations to do something about it,” he said at a Nov. 14 news conference.

Tackling the issue will involve making some tough political choices, he said, because climate change will affect different parts of the country in different ways. “I don’t know what either Democrats or Republicans are prepared to do at this point, because this is one of those issues that’s not just a partisan issue; I also think there are regional differences,” he said.

Since Obama’s comments, a handful of reports have bolstered his claim that “what we do know is the temperature around the globe is increasing faster than was predicted even 10 years ago.”

Taken together, they also provide a glimpse into what a hotter future could mean for the Pacific Northwest.

In December, the U.S. Forest Service published “Future of America’s Forest and Rangelands,” the resources-planning assessment the agency compiles every 10 years.

The report noted that steep elevation gradients in the Intermountain West — like those found in Central Oregon — will be some of the areas in the country most exposed to habitat stress caused by climate change.

“For example, although wildfires are a natural process that structures ecosystems, recent analyses suggest that climate is altering historical fire dynamics and may alter the patterns beyond that to which the (region’s plants and animals are) adapted,” the report states. “(They) will thus be affected directly by the changes in climate and indirectly by changes to natural disturbances such as fire, insect outbreaks, and disease.”

Not only will the size of the forests shrink, but the composition of trees will also change, according to a draft report by the National Climate Assessment Development Advisory Committee, an interagency government panel of scientists published earlier this month.

Within 70 years, subalpine forests will virtually disappear from the region, the report projects.

By the 2080s, the median annual area burned in the Northwest would project to 2 million acres, a 400 percent increase from the 1916-2007 period, and the probability of a very large fire year would increase from 1 in 20 to 1 in 2.

And last week, the National Oceanic and Atmospheric Administration declared 2012 the hottest year on record for the continental U.S., 3.25 degrees hotter than the average temperature during the 20th century. Worldwide, 2012 was the 10th-warmest year recorded since 1880. All 12 years of the 21st century rank in the top 14 hottest, and only one year in the 20th century (1998) was hotter than 2012.

Snow and water

“A lot of the consequences of climate change are connected to the fact that much of the water we use in the Northwest is snowmelt,” said Phil Mote, director of the Oregon Climate Change Research Institute and a professor at Oregon State University’s College of Earth, Ocean and Atmospheric Sciences. “It trickles through a lot of aspects of life in the Northwest.”

By 2050, the snowmelt will come three to four weeks earlier, according to the National Climate Assessment Development Advisory Committee report’s chapter on the Pacific Northwest, which included Mote as one of two convening lead authors. Eventually, the amount of hydroelectric power the region produces — currently enough to export up to 6 million megawatt-hours a month — will go down as more water has to be diverted to accommodate salmon and steelhead, the report projects.

By changing the times of year when rivers and streams are running at their fullest, climate change puts strain on various parts of the ecosystem, said Stephen Fitzgerald, a professor at Oregon State University’s College of Forestry.

“It warms up sooner in the spring, which means you have a longer growing season. So you’re using more water over the year, and perhaps there’s less water for streams,” he said. This means less water is available for irrigation and fish habitat, he said.

Forests and resources

The makeup of Central Oregon’s forests could gradually change, Fitzgerald said. Ponderosa pine may move upslope, crowding out mixed conifer forests at higher elevations.

With less moisture in the ground and atmosphere, trees compete and become stressed. Bark beetles hone in on trees under stress, he said.

But we can stave off some of these changes in the forest by thinning them a little wider and creating more space between trees, he said. “Thinning does triple duty,” he said: It reduces competition and helps keep bark beetles at bay; it frees up more water; and it reduces fuel for fires.

Climate change is going to play a major role in resources planning for the foreseeable future, Fitzgerald said. “There’s a lot of research going on right now. As we move forward, I think there will be more information available to help us tweak our management style in the face of climate change.”

Foresters are already considering what species to plant now based on the likely future conditions, Mote added.

“We’re changing our environment, and we need to figure out how to live with those changes,” Mote said.

2012: Hottest on record

The National Oceanic and Atmospheric Administration declared last year the hottest ever for the continental U.S., registering 3.25 degrees above the 20th-century average. Oregon east of the Cascades saw temperatures above or far above normal, while only one region in the contiguous 48 states, a sliver along the Oregon Coast, witnessed temps below normal.

Source: NOAA/NASA 2012 report on global temperatures