It's unlikely that Seattle's 605-foot Space Needle will be under water any time soon, or that Alaska will become as famous for its fruit trees and berries as Oregon is.
But there are growing indications that the Pacific Northwest, from Oregon to British Columbia to Alaska, is warming up faster than elsewhere on the planet - a trend that's likely to accelerate, according to scientists at the University of Washington in Seattle.
Glaciers and snowpacks in the Cascade and Olympic Mountains are shrinking. So is Arctic sea ice in Alaska, where the permafrost in some areas is turning mushy. Record- setting temperatures in Anchorage this summer reached a balmy 79 degrees F. Water levels in Puget Sound are rising. Annual patters of stream flow are changing in ways that could adversely impact irrigation, domestic water supplies, fish runs, and hydropower production, while increasing the risk of forest fires and tree-killing insects.
In Seattle and Victoria, British Columbia, this week, agency officials, scientists, tribal leaders, and others are participating in major conferences addressing climate change.
"Even the most conservative scenarios show the climate of the Pacific Northwest warming significantly more than was experienced during the 20th century," the University of Washington's Climate Impacts Group reported last week. The Puget Sound region warmed at a rate "substantially greater" than that of Earth's average surface air temperature, the scientists found.
Brad Ack, director of the Puget Sound Action Team, a partnership of federal, state, and tribal agencies that commissioned the report, likens what's happening to a "slow-motion natural disaster."
"This is often talked about as something that's going to happen," says Mr. Ack. "But what this shows is that this is already happening. We're well into climate change."
Economists in the region warn that this could come with a big price tag. Global warming "is likely to impose significant economic costs," 52 leading economists from around the country warned in a recent letter to government and business officials in Oregon.
"The adjustments that businesses, households, and communities will have to make are without precedent," the economists wrote. "Many changes seem largely unavoidable, and some are clearly imminent."
That's mainly because of diminishing snowpacks due to warmer winter temperatures. Snowpacks act as water "banks" throughout the region, but smaller snowpacks mean reduced river and stream flows in the summer, which negatively affect agriculture, forestry, tourism, and hydropower - major portions of Oregon's $121 billion economy.
Changes in nature from global warming also can exacerbate environmental problems, especially the natural balance in ecosystems and the wildlife they include.
"Climate change is an additional stress to systems that have already been affected and changed by human activities," says Amy Snover, a research scientist and member of the University of Washington's Climate Impacts Group.
Politically, the region - sometimes referred to as "Cascadia" - appears to have heard the message.
Since February, Seattle Mayor Greg Nickels has been pushing his colleagues in city halls around the country to sign the Mayors Climate Protection Agreement.
That pact commits them to meet or exceed the Kyoto Protocol standards, reducing greenhouse gas emissions 7 percent below 1990 levels by 2012. So far, 186 US mayors - from Issaquah, Wash. to Laredo, Texas to Schenectady, N.Y. - have signed on.
While it still relies heavily on hydropower dams for electricity (which have environmental problems of a different sort - mainly profound damage to ecosystems that support endangered salmon and other wildlife), Washington State has been building wind farms in its wide-open spaces east of the Cascade Mountains.
In Oregon, Gov. Ted Kulongoski (D) is pushing state lawmakers and reluctant auto dealers to adopt California's tougher emission standards for motor vehicles, enacted last year. If Oregon takes that step, Washington State, which shares the market for cars and trucks with its neighbor to the south, will do so also.
Portland, Ore. and surrounding Multnomah County have nudged carbon dioxide emissions to a level below 1990, a first for any major American city.
With help from two new light-rail public transit lines, the planting of some 750,000 carbon-absorbing trees, financial incentives for energy-efficient "green" buildings, and weatherization of more than 10,000 apartments and houses, per capita emissions in Portland dropped 13 percent over the past 10 years. Nationally, there's been an increase of about 1 percent per capita.
Mayor Tom Potter, the city's former police chief, drives a Prius hybrid and promotes Portland as a bike-friendly city with 750 miles of bicycle paths.
Still, officials and scientists around the region agree that more needs to be done.
"We can no longer stop this," says Ack. "We can hope to ameliorate it by mitigating greenhouse gas emissions, but we cannot stop this. So either we ignore it and suffer, or we prepare for it and suffer less."
Urged on by the group of economists, the region's elected officials and agencies now address climate change here on the basis of the "precautionary principle" - acknowledging that they do not know everything about the long-range effects of global warming, but are taking steps now before it's too late.
"It's about hedging," says Dr. Snover. "It's about risk management. It's about acknowledging that uncertainty is not going to go away, expecting to meet surprises, being prepared for that change and designing flexibility right in."