‘Cool Farms’ Mask Global Warming

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You’ve heard of urban heat islands that generate pockets of hot air. Now researchers confirm the existence of their opposite: cool farm patches that tend to cool things down, reports New Scientist. These have been felt in California for more than a century, in areas of intensive irrigation, like the Central Valley, where “cool farms” have counteracted global warming. Researchers from the Lawrence Livermore National Laboratory, extrapolating back to when irrigation began in 1887, calculate that intensively irrigated parts of the Central Valley are ~3.0 to 5.75°F cooler than they would otherwise have been. The cooling happens because much of the solar energy hitting irrigated ground during the day goes to evaporate the extra water in the soil and plants instead of heating the air. The cool farms could explain why minimum and maximum winter temperatures steadily rose in California between 1915 and 2000, while maximum summer temps did not. The warmer winters can only be explained by the greenhouse effect, and the authors speculate the cool-farms effect may have masked the impact of global warming on summer temps — since irrigation is mostly carried out during the summer.

But the cool times may not last. A rollback of the cooling effect of irrigation in the face of continued global warming could mean that California will be hit by substantial warming. This could also mean that irrigated regions around the world, which now provide about 40% of global food production, will feel more than their share of warming in the future, with the obvious impact on food security. . . So, plant your water gardens now. JULIA WHITTY

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SIX TRUTHS

Reclaiming power from those who abuse it often starts with telling the truth. And in "This Is How Authoritarians Get Defeated," MoJo's Monika Bauerlein unpacks six truths to remember during the homestretch of an election where democracy, truth, and decency are on the line.

Truth #1: The chaos is the point.

Truth #2: Team Reality is bigger than it seems.

Truth #3: Facebook owns this.

Truth #4: When we go to work, we're in the fight.

Truth #5: It's about minority rule.

Truth #6: The only thing that can save us is…us.

Please take a moment to see how all these truths add up, because what happens in the weeks and months ahead will reverberate for at least a generation and we better be prepared.

And if you think journalism like Mother Jones'—that calls it like it is, that will never acquiesce to power, that looks where others don't—can help guide us through this historic, high-stakes moment, and you're able to right now, please help us reach our $350,000 goal by October 31 with a donation today. It's all hands on deck for democracy.

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