Ask people here in the valley what evidence of climate change they’ve noticed, and you’ll hear the following: forsythia and cherry blossoms in December. Fleas in January; ticks all winter. Shorter ski seasons. May-like temperatures in March. Earlier onset and longer duration of seasonal allergy symptoms. Streams too low for paddling in spring due to lack of snow melt. More poison ivy. More weeds, generally.
Most people know that a week’s or season’s weather does not represent a change in climate. And an unusually strong El Nino—the warm phase of a naturally recurring climate pattern across the tropical Pacific—likely influenced this winter's weather.
But we are seeing long-term changes. Since 1967, the U.S. Department of Agriculture’s Plant Hardiness Zone numbers for Pennsylvania have been revised upward from 4 to 6 in the north and from 5 to 7 in the south, reflecting rising annual minimum and maximum temperatures here as in most of North America. The third National Climate Assessment Report (2014) noted that temperatures in the Northeast increased significantly between 1895 and 2011. As the report explains, a warming climate is expected to bring less frequent but heavier rainfall and other “extreme weather events,” and the amount of precipitation “falling in very heavy events” in the Northeast increased more than 70% between 1958 and 2010.
Globally, temperatures in 2015 were 0.9 degree C. above the 20th century average, continuing a multi-year trend. According to Professor of Atmospheric Science Michael Mann, director of Penn State’s Earth System Science Center, recent studies indicate that only 0.1 degree C. of this variation is attributable to El Nino. Taken singly, none of the local examples above proves that the climate is changing. Together, however, they signal a warming world.
So what are we waiting for? It’s time to take action against climate change—action that goes far beyond recycling plastic bottles, driving less, or using less energy at home. Each of us individually has a role to play, but collectively we must develop alternative energy sources, create good and secure jobs to replace those that rely on fossil fuel extraction, and drastically cut emissions of CO2, methane, and other greenhouse gases. We’ve initiated warming processes that we can’t stop. However, we have time, if we have the will, to limit their effects and preserve our ability to live, with integrity and justice, in the only world we have.
Sabrina Kirby, Lewisburg