I Wonder

edavidson

President and Senior Scientist Dr. Eric A. Davidson

Some kids wonder why the sky is blue or when the world will end! I wonder if global warming has an effect on the weather,” wrote Vermont seventh grader Molly Henne. Molly had written to me to get an expert’s advice for her “I Wonder” middle school assignment. “For example,” she continued, “this winter we have not had the regular snowfall, and the weather has been much warmer. I am interested because I love to ski, but this winter it has been a hard season with the heat.”

In the past, scientists often responded to such questions with great caution, emphasizing that they cannot attribute any single weather event or season to human-induced climate change, but that the long-term trends in climate are clearly changing. More recently, the climate science community is learning that we need a response that communicates more effectively to the pubic how climate change is playing out. For example, Dr. Kevin Trenberth of the National Center for Atmospheric Research recently wrote:

“The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.”

We can also compare the climate to a baseball player on steroids. Batters have always hit homeruns, but they started setting more homerun records when steroid use in sports started to increase. Likewise, there have always been some unusually mild winters, blizzards, floods, and droughts, but with more energy and water vapor in the atmosphere due to human-induced climate change, these extreme events are happening more frequently—we now have more frequent powerful climatic hits. Furthermore, the climate records being set are lopsided—for every record low temperature, there have been two or three record high temperatures.

In my reply to Molly I wrote: “The scientific consensus to your question is yes, the changes in climate due to accumulating heat trapping gases in the atmosphere do include more frequent unusual events, such as an increase in bad winters for skiing. Human-caused climate change is already happening, and it means that this sort of strange weather is becoming increasingly common.”

The decisions we make today about using gas, oil and coal, and about managing our forests will leave a legacy for Molly and her generation. Her inquiry left me with my own “I wonder” question—I wonder what it will take for my generation to have the courage and foresight to take the necessary steps to stabilize the climate and to leave a better world for the next generation. We need young people like Molly to keep asking us these tough questions.