Gambling With Our Climate


Climate change is loading the dice for extreme weather - or haven't you heard? The oft-repeated dice analogy didn't fully resonate for me until I read this quote from heavy-hitting climate scientist Michael Mann:

One often hears the misleading claim that no single event, regardless of how extreme or unprecedented, can be blamed on climate change. That is like saying that no single roll of a "six" with loaded dice can be blamed on the loading of the dice.

Just as the unusual number of "sixes" rolled is due to the loading of the dice, so are the more frequent and extreme weather events we are seeing due collectively to the "loading" of weather dice by increased heat-trapping greenhouse gases produced by our continued burning of fossil fuels.

In today's strip, Bebbo acknowledges that one can't definitively attribute a single storm to climate change. While Mann's quote may at first seem to be at odds with the view held by our cartoon polar bear friend, it really isn't. When it comes to describing the impact climate change has on weather events, nuances in phraseology matter.

For instance, University of Illinois atmospheric sciences professor Donald Wuebbles was recently quoted as saying, "Human-driven climate change is in fact driving changes in severe weather, and that leads to a lot of potential impacts in both humans and wildlife that end up being costly in many different ways."

See? It's driving climate change, but not explicitly linked to a single event.

How about this quote from University of Victoria in British Columbia climate scientist Andrew Weaver: "Rather than say, 'Is this because of climate change?' That's the wrong question. What you can say is, 'How likely is this to have occurred with the absence of global warming?' It's so extraordinarily unlikely that it has to be due to global warming."

We're getting close - recent extreme weather events are unlikely to have taken their final form without climate change.

James Hansen, head of NASA's Goddard Institute for Space Studies, has a similarly strong assessment. "Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change. To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change."

We're almost there - these events almost certainly could not have happened without global warming.

Finally we have the following assessment from Kevin Trenberth, senior scientist at the U.S. National Center for Atmospheric Research's Climate Analysis Section. "Yes, undoubtedly. The environment in which all storms form has changed owing to human activities. The human component does not change much from year to year and affects all storms."

Undoubtedly. Affects all storms. Got it.

Check out What on Earth at Science Friday
Like "What on Earth?" on Facebook.
Become a Fan here at The Huffington Post.