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Ingrid asks:
Heavy snows like we had last winter proved to me that global warming is not reality. But I have to admit that the heat waves and droughts a lot of the country got this summer make me a little less sure. What do blizzards and heat waves say about climate change??

Answer:
A region’s climate consists of that area’s typical seasonal weather averaged over many years. Earth’s climate consists of all the world’s regional climates averaged together. If you live in an area like the American Midwest, you can typically expect to see cold and snow in the winter and heat — sometimes extreme — in the summer. While anthropogenic (man-made) global warming is causing Earth’s climate to change rapidly, it’s not changing so rapidly that we’ve seen our last Midwestern snow fall. Imagine Minnesota without snow or cold in the winter — that’s pretty dramatic stuff..

While there is overwhelming scientific consensus that human activities are warming our planet’s average temperature, scientists are quick to point out that no one weather event can be attributed to climate change. Though I’ve heard scientists point to the particularly strange weather we’ve had recently and say that, because of climate change, it will become the new normal.

In short, a blizzard or a heat wave — even a entire season or two of extremes – is not a sign of climate change. But if we look back 20 years from now and see this year was part of a long term pattern of progressively erratic weather, that’s when scientists will really start piecing the puzzle together.

• Here’s an earlier “What on Earth?” that discusses the relationship between weather and climate.
• NASA defines climate and climate change

CAN’T GET ENOUGH WHAT ON EARTH?

WOE on Huffington Post

WOE on Facebook — get updates, climate change fun facts, download WOE avatars & desktop wallpapers and more!

Interview: Katie Kline, Communications Officer at Ecological Society of America interviewed me via Skype for the ESA’s Ecotone blog. Read and hear it here.

Video: Bebbo and Kito were featured in one of Jim Parks’ terrific Today’s Green Minute episodes. See the video! Learn moreabout it.