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State Temperature Trends Since 1st Earth Day

By Climate Central

It’s not often that a day of national celebration leads to major changes at the highest levels of government, but that’s what happened after the very first Earth Day in 1970. The Environmental Protection Agency, as well as the Clear Air and Clean Water Acts, were created soon after that historic event — and concern for the environment was suddenly on America’s radar.

At the time, few were talking about global warming. While scientists knew that certain gases, like carbon dioxide, effectively trapped heat, whether or not it was happening on a significant global scale was unclear. For the next two decades, saving the environment was mostly about cleaning up toxic wastes and saving endangered species.

But since 1970, scientists have gathered mountains of evidence that greenhouse gases are changing the climate — vanishing ice at the poles, increases in heat waves, intensification of droughts, heavier downpours, more acidic oceans, shifting ecosystems, and climbing global temperatures. Last year (2014) brought the hottest year on record, and the first quarter of 2015 is already off to a record warm start.

How Much Warmer?

To give a sense of how things have changed since the first Earth Day, we’ve analyzed how much annual average temperatures have gone up, state by state, for the Lower 48. 

As expected, there is more variation when you look regionally rather than globally, and it turns out that some states — mostly in the Southeast — have warmed more slowly than others. But every state in the continental U.S. has seen a warming trend since 1970.


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