Greenhouse Gases

What Are Greenhouse Gases?

Greenhouse gases are a class of compounds that play an important role in our planet's climate despite making up less than 0.05% of the Earth's atmosphere. These gases allow visible light to reach Earth's surface, but trap the heat radiating off the planet, warming the climate. A certain amount of greenhouse gases is required to keep our planet habitable, but large increases in greenhouse gas mixing ratios in a short period of time leads to unstable warming contributing to stronger storms, heat waves, droughts, and rising sea levels.

Carbon Dioxide (CO2 )

CO2 is the most abundant greenhouse gas in the atmosphere, with mixing ratio of 415 parts per million (ppm) as of 2020. While CO2 has many sources, the majority of emissions are from human activity involving the burning of fossil fuels like coal, oil, and natural gas, which are used to fuel our cars, power our electricity, and manufacture products. CO2 mixing ratios have been increasing rapidly since 1750. Ice core data collected in Antarctica has indicated that CO2 mixing ratios are at their highest levels in at least 800,000 years. CO2 is a long‐lived gas species that is mainly removed by photosynthesis from plants and microorganisms and absorbed by oceans. A CO2 molecule can stay in the atmosphere for 200 hundred years, meaning that emitted CO2 can have long lasting impacts on Earth's climatic system.

Methane (CH4 )

CH4 is the second most abundant greenhouse gas in the atmosphere, with an estimated global mixing ratio of 1$#46;85 ppm as of 2020. Despite having a mixing ratio 224 times smaller than CO2, one molecule of CH4 can lead to 24 times more warming than one molecule of CO2 over 100 years, making it a far more potent greenhouse gas. CH4 has a wide variety of sources, both anthropogenic like fossil fuel combustion, natural gas extraction, and agriculture, and natural like wetlands, permafrost thaw, and forest fires. Approximately two‐thirds of CH4 emissions come from anthropogenic sources and one third comes from natural sources, though the controlling factors for CH4 are far more uncertain than for CO2. Similar to CO2, CH4 mixing ratios had been increasing up until 2001, before plateauing for about 6 years, with increases resuming in 2007. The underlying cause of this plateau is still being researched.

History of Greenhouse Gas Measurements & Their Importance

Measurement of greenhouse gases only started recently at Whiteface Mountain. The measurements are part of a project funded by the New York State Energy Research and Development Authority (NYSERDA) being led by Dr. Lee Murray of the University of Rochester and Dr. Eric Leibensperger of Ithaca College with the intent of improving CH4 emissions estimates in New York. Measurements started in 2017 at the Marble Mountain Lodge using a Picarro G2301 Cavity Ring‐down spectrometer.

With a warming climate, it is imperative that any controllable greenhouse gas emissions are reduced. According to the International Panel on Climate Change (IPCC), to avoid the worst effects of anthropogenic climate change, warming must be limited to 1.5°C by 2100, requiring a reduction in CO2 emissions by 45% in 2030 and net zero emissions by 2050, with large reductions in CH4 emissions as well. Due its location away from major sources, Whiteface Mountain is a useful site for monitoring greenhouse gases. In order to help create effective policy aiming to reduce emissions, regular monitoring across the globe including sites like Whiteface Mountain is required.