Climate Change Background

Weather refers to the atmospheric conditions over short periods of time (hours to days) and generally over a more local area. Climate refers to longer-term conditions (decades to centuries) and generally at a regional and/or global scale. Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial era in which human activities, such as fossil fuel burning, increased the amount of heat-trapping greenhouse gasses in the atmosphere. Climate change is the long-term change in the average weather patterns that define local, regional, and global climates. Natural causes such as volcanic activity and changes in the Sun’s energy output do influence these climate changes but human activity has greatly accelerated these processes beyond their natural timelines (1).

Annual average temperature over the contiguous United States has increased by 1.8˚F (1.0˚C) over the period from 1901-2016. Over the next few decades, annual average temperatures are expected to rise by about 2.5˚F for the United States (2). This dramatic rise is expected to cause an increase in the intensity and frequency of extreme events such as hurricanes, wildfires, drought, and heatwaves.

Monitoring and noting the changes in these events are particularly important for human safety, infrastructure, agriculture, water quality and quantity, and natural habitats and ecosystems

In Pennsylvania, the climate has warmed more than 1.8˚F (1˚C) over the past 110 years. Accompanying this increase in temperature is a 10 percent increase in the average amount of precipitation (3). By the year 2050, Pennsylvanians are expected to see an additional increase in temperature of 5.4˚F and an 8 percent increase in precipitation (4). These changes have been related to human activities and greenhouse gas emissions in the global atmosphere.

From these changes, Pennsylvania has experienced record-breaking impacts from floods and landslides that cost $125.7 million in damages in 2018 alone. Other impacts that Pennsylvania may experience are worsened air quality, agricultural losses, damages to public infrastructure, increase in pests, diseases, and invasive species (5).

In Cumberland County, temperatures and precipitation have also increased as shown in the figure and animation below. The animation demonstrates the tail end of the extreme temperatures in the coming years for Cumberland County. This increase in temperature and precipitation creates and will continue to create harmful ramifications for the future livelihood of the county. Certain aspects of the county ranging from water supplies, agriculture, and tourism will be affected.

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