Impacts of Climate Change In Pennsylvania

According to Pennsylvania’s Department of Environmental Protection (DEP), the Keystone State has seen two big changes to their climate over the past 110 years. Not only has the state gotten a little bit wetter — there has been a 10 percent increase in precipitation during this time — but the overall temperature has also seen an average increase of 1.8 degrees Fahrenheit. And that’s not where these changes end, either. According to the DEP, the state is expected to continue to see increases in precipitation which experts say will bring us another 8 percent increase by the year 2050.

Pennsylvania’s Disappearing Seasons

While the state has gotten warmer and wetter by the DEP’s calculations, Kyle Imhoff, Pennsylvania State Climatologist, Assistant Research Professor Department of Meteorology and Atmospheric Science at The Pennsylvania State University, says that the bigger surprise is when these increases are happening. “I would say the two trends that stand out to me over the past century are the increase in warmer nighttime temperatures during the winter months of December through February (an increase of about 3 degrees Fahrenheit statewide over the last 100 years or so) and the increase in precipitation during the fall months of September through November (an increase of about 2.5 inches statewide over the last century).” 

That’s caused some unusual regional changes, which include an extension of the growing season in certain areas, which Imhoff says may be the reason so many people (myself included) have been asking what exactly happened to spring and fall. “Your perception of shortened transition seasons can at least be partially attributed to the expansion of the growing season length that has been observed over the past century, and one may also feel that the cold season in general is just a tad shorter than it used to be due to this,” he says. 

What Does This Mean for the State?

In terms of dramatic recent increases, Imhoff says that one of the largest trends observed over the past few decades is the increase in extreme precipitation events, which he categorizes as an event that drops more than 2 or 3 inches of precipitation in a 24-hour period. “Some parts of the region have observed as much as a 50-75 percent increase in the annual number of these events since the mid-1900’s.”

These changes aren’t without their risks, which Imhoff says can include inland flooding. But the more concerning long-term problem may be something else entirely. “As a result of the ‘warmer and wetter’ observations, I actually think the state is vulnerable to drought events,” he continues. “Not in the sense that droughts may become more frequent, but that the impacts of a drought may be more severe when they do occur because of the fact that the state has become accustomed to plentiful rainfall and water supply.”

In fact, Imhoff says that a severe, prolonged drought could be particularly disruptive to a region that has been so fortunate to have not experienced these types of events in recent decades.