Torrential rain in parts of Vermont, New York and Connecticut caused dramatic flash flooding last week that washed out roads, suspended rail service and swamped homes, shops and downtowns. Hundreds of motorists were rescued from cars and some residents were evacuated. A few weeks earlier, deadly heat waves engulfed parts of Texas, Louisiana and other Southern states. Heat index levels up to 112 degrees affected some Floridians, and south-central Arizona began this month with temperatures of 107 to 115. Extreme weather such as this summer's likely will increase, experts say, without more action to combat the rising global temperate trend known as climate change.

Individual weather events and long-term climate patterns are separate things, but specialists see a link. "Catastrophic flooding, in more and more places, is a clear indicator of a rapidly intensifying climate," warns Peter Gleick, author and founder of the Pacific Institute research center in Oakland, Calif. In one week last summer, the United States saw three 1-in-1,000-year downpours: 8 to 12 inches in Southern Illinois in just 12 hours, 6 to 10 inches of rain in the St. Louis area and a 14-inch deluge in eastern Kentucky that killed about three dozen people.

Climate change, which stems mainly from burning fossil fuels such as oil, gas and coal, raises the frequency of severe storms in two ways, experts say. "A warmer atmosphere holds more moisture, so when it rains there's potential for much more of it," according to Michael Mann, director of the Center for Science and Sustainability and the Media at the University of Pennsylvania. "And the pattern of warming is impacting the jet stream in such a way that we get more of these very stagnant or 'stuck,' wavy patterns which are associated with persistent weather extremes -- both heat/drought/wildfire and flooding, depending on your location."

At New York's Capitol in Albany, Gov. Kathy Hochul said last week: "Our first responders are being asked to manage more weather events than ever before. . . . . Make no mistake: This is our new normal. We are the first generation to feel the impacts of climate change and the last generation with a shot at doing anything about it."

Climate scientist says: "Arizona already understands heat to a certain extent, but it’s getting hotter for us too. That means a lot of people will continue to die." – Joellen Russell of the University of Arizona in Tucson

TV meteorologist says: "We've seen an increase in extreme weather. This without a doubt is happening. We are going to see stuff happen this year around Earth that we have not seen in modern history." -- Jeff Berardelli, climate specialist at WFLA News in Tampa, Fla.

Researcher says: "It's getting harder and harder to adapt to these changing conditions. It’s just everywhere, all the time.." – Rachel Cleetus, climate and energy policy director at the Union of Concerned Scientists in Arlington, Mass.