Climate change is becoming impossible to ignore. In 2021, an estimated four in 10 Americans lived in counties struck by weather disasters. But how exactly does climate change lead to extreme weather? Yahoo News explains.
GARIN FLOWERS: Climate change is becoming impossible for many Americans to ignore. In 2021, we saw raging wildfires exacerbated by drought in the West and severe downpours across the Midwest, Northeast, and South, snowstorms that overloaded Texas's electrical grid, deadly record-setting heat waves in the Pacific Northwest, and hurricanes that unleashed destruction from the Gulf Coast up to New England. In fact, according to an analysis by the "Washington Post," more than 4 in 10 US residents live in a county that was affected by weather disasters last year. But how exactly does a warming planet lead to more extreme weather?
When the sun's rays hit the Earth, the majority of that radiation bounces right back out into space. But naturally occurring chemicals in the planet's atmosphere known as greenhouse gases help trap a portion of that heat.
Human activity like burning coal or gasoline adds more greenhouse gases into the atmosphere, increasing the amount of solar heat that the planet retains.
The Earth has warmed by about 2.2 degrees Fahrenheit since the dawn of the Industrial Revolution. And while individuals might not be able to feel that change just by going outside on a given day, we can see the tangible effects of disruption to our ecosystems.
We've always had occasional extreme weather, but rising global temperatures have driven a rise in both the frequency and severity of these kinds of events. There are a lot of factors at play, including high and low pressure systems swirling in our atmosphere that can bring about cold snaps or deadly heat.
ALLISON FINCH: All of this hot weather is due to a large high pressure system.
GARIN FLOWERS: And when it comes to precipitation, or lack thereof, it helps to understand the relationship between weather and water.
PETER GLEICK: The climate cycle and the water cycle that most of us remember from second grade are all intimately connected. The renewable cycle of water on the planet is evaporation and the formation of clouds, and then we get rainfall and snow precipitating out again and then runoff back to the oceans and then evaporation. And that's fundamentally the climate cycle as well. As we change the climate, we have learned, over the last many decades, that we are also going to fundamentally change how much water we get and where we get it, the intensity of storms, rainfall patterns, the severity of droughts and floods. And we've moved from a world in which we expected those things to happen to a world in which we are now seeing those things happening.
GARIN FLOWERS: By warming the planet by just a few degrees, we are seeing a chain reaction take place. For every 1.8 degrees Fahrenheit of warming, the atmosphere holds about 7% more moisture. So as more water evaporates, that vapor is held longer and travels further, leading to more extreme weather and snowfall when it eventually travels into cooler areas. We see this in an increase in tropical storms making landfall as hurricanes further and further north as well as other storms carrying more precipitation further inland. We also see the other side of the extreme-- increased evaporation drying up soil and foliage leading to prolonged droughts and causing forest fires to burn hotter and longer.
The Earth's ecosystems are all connected. So small changes can have a huge impact. We hope this helps you understand a little more about your world.