Evidence of warming found in Ohio -- and I thought it was hot when I was growing up there!

Science Daily: Summer nights in Ohio aren't cooling off as much as they used to -- and it's likely a sign of climatic warming across the state, researchers say. Jeffrey Rogers, professor of geography at Ohio State University, led the new study, which found that average summer nighttime low temperatures in Ohio have risen by about 1.7 degrees Celsius (about 3 degrees Fahrenheit) since the 1960s. Why the change? It's not just the heat, it's the humidity, the researchers concluded -- coupled with increased cloudiness at night.

Three degrees Fahrenheit might not sound like much of an increase, but it is -- even though daytime highs have remained mostly the same, said Rogers, who is also the state climatologist for Ohio.

"A lot of Americans might expect that global climate change would cause extremely high daytime temperatures in the summer," he said. "But in Ohio at least, the high temperatures haven't been changing -- it's the overnight low temperatures that have been creeping up. That means the average temperature over the 24-hour period is creeping up as well."

And this is exactly how Rogers believes that climate change would manifest itself in this region of the Midwest -- nighttime lows are rising, so that over time there would be less difference between them and the daytime highs. That would mean a big change for Ohio, where a typical summer night is 20 degrees Fahrenheit cooler than the day.

In fact, stronger evidence of climate change would be hard to come by here, Rogers said: "In Ohio, we don't have a clear signal of global change, like you have in the Arctic, where sea ice is melting. But these rising nighttime lows are the next closest thing."…