In increasing numbers, scientists are in agreement that the earth’s climate is changing, and human carbon dioxide emissions are contributing to those changes. A NASA climate scientist was in Louisville this weekend to talk about the growing evidence.

Gavin Schmidt is a climate scientist at NASA’s Goddard Institute for Space Studies. He says scientists have exhaustively studied the numerous signs of climate change—like warming oceans, melting glaciers—and then compared them to the fingerprints of different things. Like, are all these events being caused by sun brightness? Or volcanoes? He says they’ve narrowed it down, and the only culprit left is increases in carbon dioxide emissions.

“It’s like we’re CSI Planet Earth, and we’ve looked at all the different suspects and matched their DNA, and there’s only one suspect that’s still in the picture,” he said.

Schmidt says it’s disturbing that scientific results—even ones that could affect policy—are being attacked in political arenas.

“The scientists here are really just messengers,” he said. “If your only response to the science is to shoot the messenger, then nature is going to give you a very clear wake up call.”

Schmidt says science is already in unknown territory, because the climate and carbon dioxide levels have never been quite what they are now. He says the damage is likely irreversible, but with careful policy decisions, over the next few generations people will be able to slow the warming.

The way climate change will affect coastal towns like New York and Miami is obvious—there will be flooding. In the Ohio River Valley, Schmidt says the future will likely be a continuation of the past year: hot, dry summers and short but very intense rainfalls, which will increase flooding.

Erica Peterson is WFPL's News Director.