President Trump's decision to exit the Paris Agreement (aka, Paris climate accord) is disappointing to many, but not unexpected. Companies, individuals, and organizations of all kinds have decried the decision as a major step backwards in the face of the very real threat of climate change. And rightly so.
But how much material effect will the president's decision have on a country that has built significant momentum towards curbing greenhouse gas emissions? I don't think the country's retreat from common sense policy will cause anywhere near the amount of harm to our carbon footprint that some people fear. The Paris Agreement demonstrates the cooperation of over 200 countries to safeguard the planet for future generations, but a piece of paper alone does not dictate all activity on the matter.
Cities and states are forging ahead with climate change solutions regardless of the current or any future official position of whomever happens to occupy the White House. California is sometimes referred to as the world's 6th largest economy (on its own, in terms of GDP, it is ahead of France and behind the UK). Even if the rest of the U.S. did nothing to cut carbon, California's commitment alone to the targets set forth in the Paris agreement would make a big difference on the world stage. Chicago, Illinois, and many other states and cities are likewise committed to reducing their carbon emissions.
Moreover, the good old days of coal are not coming back regardless of President Trump's decision. In today's economy, renewables (wind and solar) and natural gas simply make a lot more financial sense than coal these days. Coal is having difficulty competing with these other sources, with or without subsidies. Investments have been exiting the coal industry for years, before the Paris Agreement was ever developed. And even excluding the issue of carbon, renewables and natural gas make a lot more environmental sense than coal. Yes, continued research and development into "clean" coal technologies may improve coal's appearance, but the additional infrastructure expense will only render coal-fired plants even more financially unfeasible. No person, president or otherwise, has the power to single-handedly reverse years-long trends within the $1-trillion-dollar domestic energy industry.
The greatest harm from the U.S. exiting the Paris Agreement may be its symbolic reinforcement of our changing role on the world stage. It looks very bad for the U.S. to be one of only a few countries (Nicaragua and Syria being others) to not be a signatory to it. One old argument made by opponents of this sort of agreement is that the U.S. shouldn't try to reduce carbon emissions if major new polluters such as China and India are increasing their carbon emissions. Put aside the fact that the U.S. (and other Western nations) had a huge head start in putting a lot of carbon dioxide into the atmosphere over the many decades since the Industrial Revolution. Even so, that old argument no longer holds: China and India both support the Paris Agreement. In this respect, the U.S. is no longer leading the charge; it is bringing up the rear.
Announcing the goal of a manned mission to the moon, President Kennedy famously said, "We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win…."
The decision to exit the Paris Agreement basically says to the world the exact opposite: that we give up, that we are okay with losing, and that we won't even join in the fight to attempt to win.
Earth is not going to die, and climate change may not noticeably occur at a faster pace, just because the U.S. is quitting the Paris Agreement. But from the standpoint of global leadership and diplomacy, the U.S. has lost bigtime.