TSRC Town Talks: Clouds & Climate Change
Finicky and ephemeral, clouds are hard to pin down. That’s exactly what makes Graham Feingold’s research so difficult. Feingold, a research scientist at National Oceanic and Atmospheric Administration (NOAA), studies the future of clouds in the face of climate change. He will speak on this subject at the Telluride Conference Center in Mountain Village at 6 p.m. on Tuesday, June 28, part of the series of Telluride Science Research Center’s weekly Town Talks.
“Clouds are the biggest uncertainty in predictions of climate change. If we knew how clouds would respond in a warmer world, it would help us understand how climate will change in the future,” Feingold says.
Most importantly, clouds reflect energy. Low-level clouds close to the earth’s surface reflect energy and keep the planet cooler by offsetting some greenhouse gas warming. But not all clouds are beneficial: high cirrus clouds trap outgoing energy made by aircraft.
Feingold’s question, then, is this: “In a warmer climate, will we have more clouds and more reflection of energy that will keep us cooler? Or will we have fewer clouds in which case the heating is going to get even stronger?”
Relying on numerical models to simulate clouds and taking measurements with aircraft and satellites, Feingold and his team probe the physics of clouds: “If we can understand how clouds work, we can begin to predict their presence in a warmer climate. Understanding the processes is key.”
But the changeable nature of clouds makes understanding difficult: a change in temperature or the amount of moisture impacts whether clouds form. When air goes up, it cools and all the water vapor it carries condenses. Think of putting a cold can of soda out on a hot day. The can cools the air around it, creating condensation on the outside. This condensation latches onto aerosols—suspended particles like dust—in the atmosphere, making droplets. Without particles, it’d be extremely difficult to produce clouds.
A higher concentration of particles, and therefore a higher concentration of droplets, means a higher concentration of clouds. If there are many droplets, these clouds have a harder time producing rain than if there’s that same amount of water condensing on fewer particles when it’s more likely to rain.
In Telluride, when we wake up in April and see red dust invading our snowbanks and windows, this is the work of clouds.
“Clouds in that sense are very helpful since they’re cleaning the atmosphere. Think of all that dust we would breathe if the clouds didn’t remove that material through rain or other processes,” Feingold says. However, it’s a significant problem when it results in our snow melting more quickly by darkening it with dust or other particles, which causes it to absorb heat.”
Clouds are complicated and vital to the state of the planet. When it rains every afternoon later in the summer, think about how important it is that the clouds are there, helping us instead of our complaining about that missed bike ride.
I’ll try if you do.
About the TSRC Town Talks:
TSRC Town Talks are a series of weekly talks for the public, sponsored by the non-profit Telluride Science Research Center. Over 1,400 scientists from all over the world come to Telluride each year to discuss new ideas and build research partnerships. Learn more at telluridescience.org.
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