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 )
Carbon Dioxide is the most abundant greenhouse gas in the atmosphere, with globally averaged mixing ratios approaching 430 parts per million (ppm) in 2026 and increasing rapidly. 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. Paleoclimate data indicates that CO2 mixing ratios are at the highest levels in likely more than 3 million 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 hundreds to thousands of years, meaning that emitted CO2 can have long lasting impacts on Earth's climatic system.
Methane (CH4 )
Methane is the second most abundant greenhouse gas in the atmosphere, with globally averaged mixing ratios approaching 1.95 ppm as of 2026. Despite being more than 200 times less abundant than CO2, one molecule of CH4 is estimated to result in 27-30 times more warming than one molecule of CO2 over 100 years, making it a far more potent greenhouse gas. Methane 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. Methane 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 Whiteface Mountain Base site using a Picarro G2301 Cavity Ring‐down spectrometer.
Methane measurements were added at the Whiteface Mountain summit starting in 2024 with a Picarro G2204 Cavity Ring‐down spectrometer, in collaboration with NYSDEC.
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 to its location away from major sources, Whiteface Mountain is a crucial site for monitoring greenhouse gases. In order to help create effective policy aiming to reduce emissions, regular monitoring across the globe including remote sites like Whiteface Mountain is required.
