Donald Trump

Climate Scientist Explains: Worst That Can Happen After Paris Withdrawal

President Donald Trump announced on Thursday that the United States will withdraw from the Paris Agreement, which aims to curb greenhouse gas emissions in an effort to combat climate chance.

What does it mean for the planet?

NBC News reached out to Dr. Ben Sanderson, a scientist at the National Center for Atmospheric Research in Boulder, Colorado, who researches the effects of climate change, for some answers.

Q: Let's say the Trump administration does nothing to encourage reducing greenhouse gas emissions over the next four to eight years. Can the next president simply restart those efforts or will the president's inaction constrain their future options? 

SANDERSON: The pause in action alone would translate into additional long-term warming. If the U.S. does nothing for eight years, the associated emissions would correspond to 50 billion tonnes of CO2, which would translate to long term warming of ~0.1 degrees C. But the risk is that other countries will use U.S. inaction as an excuse to relax their own efforts — which would mean the world would certainly overshoot the Paris 2 degree temperature ceiling. 

Q: The president also cited an MIT study (its authors say incorrectly) to argue that even if every country were to reach its emission targets, it would still fall far short of its goal of preventing a 2 degree Celsius increase in temperature. What do you make of this critique? 

SANDERSON: This is partly true — the current emissions goals do not get the world to 2 degrees, but again [it's] missing the point that the initial Paris commitments are not meant to be final and mitigation would be increased conditional on global enactment of the initial goals.

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