[Illustrations, footnotes and references available in PDF version]
Summary for Policy Makers
In this report, we provide a review of Pennsylvania’s climate history and show that there is little observational evidence of unusual long-term climate changes taking place that could be linked to anthropogenic “global warming”—despite the frequent prognostications to the contrary, often accompanied by doom and gloom scenarios. Instead of rising temperatures, the state’s annual average temperature has remained relatively unchanged over the past century. Instead of an increasing frequency of drought, the state’s moisture conditions have improved over the long run. Instead of failing crops, the state’s agricultural yields have been increasing. Instead of worsening impacts from heat waves, the state’s population has become less sensitive to extreme high temperature events. Air quality has improved. Vector-borne disease outbreaks are more a matter of extant climate and social conditions than climate change. And the change in the water levels of the Great Lakes is more strongly tied into natural variability than climate change.
Further, we also show that any efforts to mitigate future climate change by legislation to curtail greenhouse gas emissions from Pennsylvania are doomed to fail—no matter how great the proposed emissions reductions. Even a complete halt to all greenhouse gas emissions from Pennsylvania will result in no detectable change in the future rate of global temperature or sea level rise. In fact, the global year-over-year increase in greenhouse gas emissions is three-and-a-half times the total annual emissions from Pennsylvania. This means that a complete cessation of all greenhouse gas emissions from Pennsylvania—now and forever—would be totally subsumed by global emissions growth in only about four month’s time. Clearly, any plans aimed at merely reducing emissions to some arbitrary level will fare even worse.
But what’s worse is that while emissions reduction plans will have no impact on the state’s climate, they will have a large and negative impact of the state’s economy. Such plans are a perfect recipe for disaster—they are all pain and no gain.