City halls around the world light up in green after Trump pulls U.S. from Paris Climate Agreement

Landmark buildings around the world were bathed in green light after President Donald Trump announced that he is withdrawing the U.S. from a landmark, international climate agreement.

Cities from Washington, D.C., to Sydney lit their city halls up in green in support of the Paris Agreement -- which went into force in 2016.

In spite of the fact that Trump plans to withdraw from the Paris agreement, dozens of mayors and governors around the U.S. are still committed to taking action to prevent the worst effects of climate change that will harm their cities.

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"President Trump can turn his back on the world, but the world cannot ignore the very real threat of climate change," New York City Mayor Bill De Blasio, said in a statement Thursday.

"This decision is an immoral assault on the public health, safety and security of everyone on this planet. New Yorkers are already experiencing hotter summers, more powerful storms and rising seas, which disproportionately affect already vulnerable communities," he added. "On behalf of the people of New York City, and alongside mayors across the country, I am committing to honor the goals of the Paris agreement with an Executive Order in the coming days, so our city can remain a home for generations to come."

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New York Governor Andrew Cuomo also announced a $1.5 billion investment in renewable energy projects on Friday in response to Trump's rejection of the climate agreement.

By withdrawing from the agreement, Trump is making good on a promise he made on the campaign trail.

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However, his decision to pull the U.S. from the voluntary agreement isolates the country from most of the rest of the world. The U.S. will now join Syria and Nicaragua as the only countries that haven't signed on.

That said, Nicaragua actually refused to sign on because its diplomats believe that the Paris Agreement is too tepid in its ambitions to curb climate change, not because they are in denial that the problem exists.

The same can't be said for Trump.

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In the past, Trump has said that climate change is a hoax, and he appointed many people along the spectrum of climate denial to major positions in his cabinet. In his speech on Thursday, Trump never acknowledged the reality of global warming or its seriousness.

Environmental Protection Agency Administrator Scott Pruitt -- a climate denier himself -- was one of the main people advocating that Trump leave the Paris Agreement behind.

Although some politicians may not believe that human-caused climate change is real, the scientists studying it have shown that it is.

Thousands of years of data point to the idea that our climate is changing and that human emissions of climate warming greenhouse gases are to blame.