Sixty years from now, if global warming continues — even with a less aggressive trajectory than the current pace — there will be good news for Lehigh Valley residents who detest snow.
But that’s about where any good news ends.
The climate of Allentown in 2080 will resemble the humid subtropical climes of Jonesboro, Ark., according to a paper published recently in the earth science journal Nature Communications. An interactive map created by the scientists provides a startling picture of North America’s climate transformation.
The disappearance of snowy Keystone State winters won’t vanish without a whole host of other ecosystem-altering changes — drenched winters, parched summers and a jarring realignment of our seasonal weather cycle.
“This is bad news for Pennsylvania,” said Dork Sahagian, an earth and environmental science professor at Lehigh University. “And it’s going to be bad news for Pennsylvania’s economy.”
Scientists Matthew C. Fitzpatrick, at the University of Maryland, and Robert R. Dunn, at North Carolina State University, created climatic analogs for 540 North American urban centers. The analogs provide a rough glimpse into how temperature and precipitation changes brought on by climate change would reshape the continent by 2080 — a span of time that is within the lifespan of today’s children.
The models that Fitzpatrick and Dunn compiled provide easy-to-digest comparisons for a public that sometimes struggles to grasp the changes threatened by global warming, Sahagian said.
On average these analogs show that North American urban areas are most likely to resemble the climate of locations about 528 miles away and mostly to the south. For Pennsylvania cities Allentown, Harrisburg and Pittsburgh, that’s Jonesboro. Philadelphia will feel more like New South Memphis, Tenn. East Stroudsburg will feel more like Sikeston, Mo., according to the data.
A few more examples: Charlotte, N.C., lines up with Tallahassee, Fla.; Burlington, Vt., will feel more like Taylorville, Ill.; and Houston will resemble Ciudad Mante, Mexico.
These changes ought to shock most people, Sahagian said, but what a simple interactive map noting such analogs cannot convey is how quickly and violently these changes will affect local environments.
Pennsylvania, he said, will get a whole lot wetter in the winter, and flooding over frozen ground is sure to cause serious issues for infrastructure. The average low in Jonesboro in January is 32 degrees with an average high of 51 degrees. The average low in January for Allentown is 20 degrees. The average high is 36.
Despite those soaking winter months, summers in Arkansas are arid. Summers in this scenario would be 24 percent drier and 8 degrees warmer than current Pennsylvania climes. July’s average high in Arkansas is 92 degrees and the low is 73 degrees. Allentown’s average high in July is 84, the average low 63.
Sahagian said these changes would significantly impact agriculture, including dairy farmers as cows produce less milk in the heat. It could also spell trouble for Pennsylvania’s lucrative export: electricity. The state is so good at generating power because it’s rich in rivers, but water levels in these new, drier summers would likely be insufficient for power plants — and at a time when hotter summers will increase demand.
Changes to our seasons already have begun, Sahagian said — with trees budding earlier in the spring and leaves shedding later in the fall. The timing of these plant life cycles provide the basis for so much else in the ecosystem, including migration and mating.
Diane Husic, the dean of Moravian College’s School of Natural and Health Sciences, said these kinds of environmental changes will run the gamut — from an increase in dangerous vector-borne diseases like the West Nile virus to drastic changes in outdoor recreation as cold water fish such as trout have trouble surviving in warmer streams.
Northern species of trees, already beginning to suffer, will face massive die-offs, Husic said. Replacing them will be difficult because while the climate may be Arkansas-like, the nutrients and geology that support southern tree species won’t be present in Pennsylvania soil.
Working to mitigate these changes will be costly, Sahagian said, but it won’t be nearly as expensive as adapting and repairing after the fact.
“These models can bring to the public eye the real meaning of what climate change can do,” he said.
