Global Warming and Weather

If I were to answer the question, “what are the connections between climate change and the extreme weather we’ve been having?” I would have to use Kevin Trenberth for help. Kevin Trenberth is a scientist at the National Center for Atmospheric Research. He’s spent a lot of time studying climate variability. More recently he studies the global water cycle and how it’s responding to climate change. He has written many scientific reports as well as currently leading a world climate research program. In his talk at the 2013 Seattle Science Festival he explained that because of the increase in temperature over the past century the water cycle is actually speeding up. Water is evaporating more quickly and forming into clouds which become more dense more quickly, causing intense rain. This is also the reason for drought in many places; water has evaporated quickly with higher temperatures, so if there is no moisture in that area the drought is more intense. He continued to explain that because there is more evaporation there is more moisture in the atmosphere, meaning heavier rains, which is what is happening recently. Furthermore as Richard Keer stated in his article in Science Magazine “In the Hot Seat”, that, “global warming has increased the chance of extreme events” but there is not one event in particular that can be directly linked with global warming alone.

I think an excellent but simple analogy to help explain this is one that Trenberth used during his talk in Seattle. He related the Earth and global warming to a person taking a hike in the Summer. If that person fails to bring water with them, they will only be sweating and not taking in any moisture, which could lead to a heat stroke. If the Earth quickly evaporates without rain, we see extreme droughts. Another analogy that was mentioned in Dan Satterfield’s article “Welcome to the New Climate” relates the weather and climate to a baseball player taking steroids. He explains, “Can you say that he hit a home run because of the steroids? No, he likely hit quite a few before he was on steroids. The steroids just made it more likely he would knock the ball out of the park. Increasing greenhouse gases make it more likely that we will see heat waves like this.”

If you'd like to watch all of Kevin Trenberth's talk at the Seattle Science Festival click here!