For Seattle residents, rain - and lots of it - is a fact of life. But they'd never seen a month quite like November 2006. With 15.59 inches of rain - including snowfall and hail - it set the record for wettest month, according to the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center. It was the most rain the Emerald City had ever seen in a one-month span, in 115 years of record keeping.
If that weren't enough, mid-December brought supercharged winds of 60 to 90 mph that cut power to about 1 million people, some of whom lived in the dark for prolonged periods.
"It wasn't just for a couple of hours, a couple of days," said Eric Holdeman, former director of the King County, Wash., Office of Emergency Management. "There were folks without power for 10 days in isolated areas, or even longer than that."
That same month, drought plagued parts of Minnesota, Wyoming, Nebraska, Texas and Oklahoma; thunderstorms and tornadoes whipped through the South; a cyclone lashed the Eastern coastline from South Carolina to Virginia; and the earliest snowfall on record fell on Charleston, S.C., and Savannah, Ga., according to the National Climatic Data Center.
Worldwide patterns show an increase in heavy precipitation and intense droughts caused by a warmer atmosphere, increases in water vapor and a rising sea-surface temperature - all results of global warming.
Holdeman, now principal at ICF International's Emergency Management and Homeland Security team, holds last winter's unusually hazardous weather events as anecdotal evidence that our weather reality is shifting.
"Whatever the cause is, the weather is changing," Holdeman said. "There's been any number of extreme weather events happening."
Scientists may not agree on some of the possible effects of global warming, but most do agree that it's happening, said Gabriel Vecchi, research scientist at the NOAA Geophysical Fluid Dynamics Laboratory in Princeton, N.J.
According to a February report by the Intergovernmental Panel on Climate Change (IPCC), the nation is already seeing warming effects in the Western mountains and melting of the snow pack; with increased winter flooding and summer warming; through pests and wildfires plaguing forest environments; with the intensifying of heat waves; and in hurricanes pounding coastal cities.
Unfortunately any changes related to the planet's increased temperature will be magnified in developing countries, where resources won't be available to delay or minimize effects. But in richer nations, like the United States, where the resources are forthcoming, it's time to adapt and plan for changes we might see, or are seeing now.
The most egregious global warming effects will occur on global warming's frontlines - at the poles, where there's damage to ecosystems and thawing of glaciers and ice sheets, and on small islands, where beach erosion and storm surges are expected to further deteriorate coastlines, according to the IPCC.
Though most scientists agree that global warming is happening, the question of how exactly it will manifest remains. Many believe, however, that warming oceans may be contributing to more devastating hurricane seasons.
The 2004-2005 period was one of the most active 24 months ever witnessed in the Atlantic basin, setting records for number of hurricanes and tying the 1950-1951 record for most major hurricanes with 13.
But hurricanes don't just endanger lives; they also threaten people's livelihoods, businesses and homes, and cities' economies. And because tropical storms tend to hit the United States in its sweet spot - expensive and growing coastal stretches from Texas to Maine - they represent one of the country's gravest storm challenges.
Hurricanes that hit the Gulf Coast region during the 2004 and 2005 storm seasons produced seven of the 13 costliest hurricanes to hit the United States since 1900 (after adjusting for inflation), according to an April 2007 report