Climate Change

A History of Change

The land of Valley Forge has played many roles throughout human history and has always been a place of resiliency and transformation. As home to indigenous peoples, as host to the farm fields and industries of European colonists, as the location of the winter encampment of George Washington and the Continental Army, as Pennsylvania's first state park, and as part of the National Park System, Valley Forge is known for its exceptional cultural and natural resources and its value as a vibrant recreational area. With such a vital and dynamic past, change has been the one constant.

And more change is happening! However, some transformations are harder to notice than that of an army cutting down every tree for miles and building thousands of huts in a matter of weeks.

Big storms like Ida may feel like once-in-a-lifetime events, but as the effects of climate change continue to affect our world, it's possible that similar storms and flooding events will become more common. To prepare for an uncertain future, we use data and the tools of science to model what the effects of a changing climate might look like.Projections for precipitation and temperature can help inform management decisions. Keeping track of how plant growing zones and seasons are shifting over time, the encroachment of invasive plants, and the likelihood of severe weather events, we can work to be better prepared and resist some of the climatic changes we see on the horizon.

Illustrated black and white aerial view of valley forge in 1890 — Birds eye view of Valley Forge in 1890
VAFO Archives/Library of Congress 1971/James B Moyer 1890

View from the top of hill on dirt road overlooking a river — View from Stoney Battery (present day Gulph Rd, Sunset Hill) overlooking th Schuylkill River and Washington's Headquarters, 1912
NPS VAFO Photo Archive

Vintage cars on road next to family sitting in the grass under a pink flowering dogwood tree — Vintage illustration of a family enjoying the flowering dogwood trees at Valley Forge, 1957
NPS VAFO Photo Archive

Aerial view of national memorial arch with cars driving around it — Aerial image of the National Memorial Arch with a road encircling it, 1975
NPS Photo Archive

Learn More

Want to Learn More?

Climate Change effects all parks differently, check out the links to the right to learn more about how Valley Forge National Historical Park is being affected by climate change, and about the science behind these effects and more!

Graph showing upward trend in atmospheric CO2 concentration — Graph of atmospheric CO2 concentration as measured from the Mauna Loa Observatory in Hawaii since 1958.
UC SanDiego Scripps Institute of Oceanography

What is Climate Change?

On average, the Earth's climate fluctuates because of natural processes. However, scientists now agree that the present rate of climate change is far outside the norm, and is caused by human activity. The earth's atmosphere is made up of many different gases, some of which are known as "greenhouse gasses" because of their ability to hold heat. This layer of gas in the atmosphere acts as a blanket to keep the planet warm enough for us to live on it. However, human activity like the burning of fossil fuels has caused unnaturally high concentrations of these gasses to accumulate in the atmosphere, causing a more rapidly warming climate. One way this effect has been tracked is through measuring concentrations of gasses like carbon dioxide(CO2) in the air. One example of climate research like this is seen on the right, a graph known as the 'Keeling Curve' shows a data set from 1958 to the present day of daily atmospheric CO2 concentration measurements.

You may have heard of issues like sea level rise, melting glaciers, flood, or wildfires effecting places far and wide, but how can climate change effect Valley Forge? While the effects may be less apparent than an army cutting down all the trees for miles to build huts, the effects of climate change can be seen in southeastern Pennsylvania, and will likely become more extreme as time goes on. Things like more extreme temperatures and storms, or shifts in growing seasons and geographical areas for flora and fauna are more subtle, but ongoing challenges to the historic landscape.