The Trump administration on Thursday revoked a scientific finding that climate change is a danger to public health, an idea that President Donald Trump called “a scam.” But repeated scientific studies say it’s a documented and quantifiable harm.

The 2009 endangerment finding affirms that carbon dioxide and other greenhouse gases pose a threat to human health and welfare. Its repeal marks one of the most significant deregulatory actions in U.S.

A warming Arctic can stretch the polar vortex, a high-altitude air ribbon, one says. The “wobble” can disrupt the jet stream, causing extreme cold in the East.

Warming is occurring across most U.S. states, though the pace and type of temperature changes vary widely from region to region.

According to the report, 13 cities have shrunk by three weeks or more. Science is clear that climate change is driven by human activity,

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Add Yahoo as a preferred source to see more of our stories on Google. Migraines can be debilitating – and frustrating when triggered by weather you can't control. fizkes/iStock/Getty Images Plus “Is it just me, or is there a storm coming?” If you are ...