A drought that began in 1999 has affected the Colorado River Basin and is often called a megadrought. The river supplies water to seven US states and to Mexico. Scientists say the drought comes from rising temperatures and lower precipitation, especially reduced winter snow.
Researchers Jonathan Overpeck and Brad Udall report that the recent drop in precipitation is linked to human activity. They once thought the lower rainfall might be natural variability, but new data changed that view. Their updated graphs in this year's Colorado River Basin report show the long-term pattern will bring more dry winters than wet winters unless people act on climate change.
Difficult words
- drought — a long period with little or no rain
- megadrought — a very long dry period that affects regions
- basin — land area that drains water to a river
- precipitation — water that falls from clouds, like rain
- variability — the quality of changing up and down
- link — to show a connection between two thingslinked
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Have you noticed dry weather or less snow where you live?
- What changes could people make to act on climate change?
- Why is winter snow important for rivers like the Colorado?
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