When scientists talk about a climate that is getting warmer, they often talk about 2 degrees of change as being enough to cause irreversible changes in the earth’s climate system. But what makes “2 degrees” important? It’s true that a 2 degree change in daily temperature is barely noticeable in the day to day variability of weather. However, 2 degrees in the climate record is a much bigger deal because while weather variations tend to cancel out over the long haul, a trend towards warmer temperatures every day can bring extremes that are harder to deal with. This essay by Dr. Katharine Hayhoe of Texas Tech University explains why.
