Like a baseball player on steroids, our atmosphere has been “juiced” with human emissions of greenhouse gases, which means we are going to be breaking heat records at an “unnatural” pace for a long, long time. Climatologist Richard Alley offers a different analogy in a column today:
Humans have made some extreme weather events more likely, and they are happening.
Just as a back-street gambler might beat someone in an honest game but has a better chance with loaded dice, Nature might have caused this summer’s weather but we gave it a boost. More importantly, under business as usual, today’s children may one day think of this summer as cool.
How extreme has the weather been in 2012?
- The U.S. Climate Extremes Index (USCEI), an index that tracks the highest and lowest 10 percent of extremes in temperature, precipitation, drought and tropical cyclones across the contiguous U.S., was a record-large 44 percent during the January-June period, over twice the average value. Extremes in warm daytime temperatures (83 percent) and warm nighttime temperatures (70 percent) covered large areas of the nation, contributing to the record high value.
Here’s the chart: