Climate Change at Catoctin Mountain Park

Image of a solar flare in the sun's atmosphere
Heat from sunlight is trapped by greenhouse gases in Earth's atmosphere, warming the planet.



Greenhouse Gases

Many chemical compounds present in Earth's atmosphere behave as 'greenhouse gases'. These are gases which allow direct sunlight to reach the Earth's surface unimpeded. As the sunlight warms the surface, heat is radiated up to the atmosphere. Greenhouse gases absorb this energy, thereby allowing less heat to escape back to space, and 'trapping' it in the lower atmosphere.

Atmospheric concentrations of both the natural and man-made gases have been rising over the last few centuries due to the industrial revolution. As the global population has increased and our reliance on fossil fuels (such as coal, oil and natural gas) has been firmly solidified, so emissions of these gases have risen. While gases such as carbon dioxide occur naturally in the atmosphere, through our interference with the carbon cycle (through burning forest lands, or mining and burning coal), we artificially move carbon from solid storage to its gaseous state, thereby increasing the amount of carbon in the air.

Deforestation is the second most important cause of increased carbon dioxide in the atmosphere after the burning of fossil fuels. Trees are an important storage of carbon, concentrating gaseous carbon from the atmosphere as wood, where it can no longer trap solar heat. When forests are burned and converted to agriculture, that carbon is released and the potential of the forest to continue to store more is lost. This is currently a huge problem facing the tropical rainforests, which are being harvested and turned into pasture, development, and farm lands at an increasing rate. In the Amazon alone, scientists estimate that the trees contain more carbon than 10 years worth of human-produced greenhouse gases.

This chart shows the path of energy as light from the sun. Some of the energy is trapped in the greenhouse of the atmosphere, the rest seeps into space.
Greenhouse gases trap energy from the sun in Earth's atmosphere. Instead of all escaping into space, the energy heats up our planet. This is natural, but human activity is increasing the concentration of these gases in the atmosphere.

Environmental Protection Agency

Historical photograph of three colliers sitting next to their hut made of sticks.
Three colliers sit next to their hut made of sticks and mud. The history of charcoal making on the mountain is a part of Catoctin’s changing energy story.

Changes in the Park

Climate is one of the primary drivers of the processes that make an ecosystem look and function the way it does. Although the Earth’s climate naturally fluctuates, scientific evidence shows that the climate is now changing more rapidly and severely than it has in the past, due to human activity. While weather reflects the daily conditions of the atmosphere, climate consists of long-term averages, usually in 30-year periods. Due to these changes, the mid-Atlantic region is becoming warmer, and receiving more rain.

Changes in annual temperature, precipitation, and the timing of spring and fall could alter what plants and animals can thrive in Catoctin Mountain Park. All living and nonliving components of an ecosystem are connected: remove one piece and all life is affected. New changes put greater pressure on species already under stress from habitat loss, competition with invasive species, and disease. Some species will fare better under changing weather patterns, some will fare worse. The transition to a “new normal” could impact all life.

The emerald ash borer (an insect native to Asia) is one example of a pest that is putting pressure on the park’s forest. It has killed millions of ash trees in the US, and is 100% fatal. The USDA estimates that if it spreads unchecked, losses to the forest products industry could reach upwards of $20 billion dollars in the United States. White ash is a commonly found tree at Catoctin Mountain Park, and there is clear and dramatic evidence of its decline within the park.

As a leader in the conservation of our nation’s most valuable resources, the National Park Service has developed a Green Parks Plan to provide parks across the country opportunities to reduce greenhouse gas emissions. In this sprit, the park is working towards ensuring greater energy efficiency in our operations. Not only is conserving resources better for the planet, it also saves money.


Some Effects on Humans Populations

Climate Change is not only an issue for what we call the “natural world”, it will have direct impacts on people as well. Some of these (such as the spread of Lyme disease) are already occurring in Catoctin Mountain Park.

  • Lyme disease: Winters are becoming compressed in length. Fewer days with subfreezing temperatures allows more ticks to survive through to the spring, increasing the risk of contracting tick-borne illnesses such as Lyme disease. Lyme disease is not the only increased health risk associated with climate change.

  • Fishing: Stream temperatures are expected to rise, making it harder for native brook trout (docx. 5.52MB) to survive in the park.
  • Bears: As winters become warmer, the hibernation cycle of park black bears is also disrupted. Since they are more active throughout the year, human-bear conflicts may increase.
Fall foliage on display at the Hog Rock Overlook
Eastern Forests and Climate

Changes in seasonal weather could have an impact on eastern forests, and the animals that call them home.

Extreme closeup of a deer tick on a blade of grass.
Health and Climate Change

Mosquito and tick-borne diseases are on the rise in a warming climate.

An electric car is plugged in and charging.
Sustainability in the Park

From alternative fuels to energy saving appliances, the park is working towards a low carbon future.

A group of volunteers holds shovels and loppers.
How You Can Help

You can be a part of the solution. At home, on the road, and in the park – get involved!



U.S. National Park Service. Climate Change Trends for Resource Planning at Catoctin Mountain Park, Maryland (doc. 9.3MB) Climate Change Response Program. Washington, D.C., 2012.

US Global Change Research Program. Climate Change in Eastern Forests and Woodlands. Washington D.C., 2008.

Office of Plant Industries and Pest Management. “Emerald Ash Borer.” Maryland Dept. of Agriculture.

Brownstein, John S., Theodore R. Holford, and Durland Fish. “Effect of Climate Change on Lyme Disease Risk in North America.” EcoHealth 2.1 (2005): 38–46. PMC.

P. Hitt, Nathaniel, et al.Forecasting stream habitat and brook trout responses to climate change in Catoctin Mountain Park. U.S. Geological Survey. 12 December 2017.

Last updated: May 2, 2020

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