"We're only looking at four years." So said Ben Carson about the possibility of Donald Trump turning out to be "not such a great president." But the impacts of decisions made over the next four years could last much longer: There is a lot a president can do to alter the course of the country, even with a hostile Congress.
In climate change policy, Trump could set us on a course of planetary destruction that we are unable to fix after he leaves office. On the economy, the growing recovery could easily be reversed with a tax policy that favors the wealthy and an immigration policy that deports a large section of our workforce. A Trump presidency could affect the long-term future even after he left office, say a number of futurists and activists we spoke to, which should make anyone who's considering sitting this election out reconsider.
By some estimates, we have five years before the world's 1.5°C carbon budget is blown. In other words, if we keep pumping out carbon emissions as much as we are now, in five years we'll have filled the atmosphere with so much pollution that there is a good chance we'll tip over 1.5°C of warming, the limit that scientists consider the edge before the environment suffers damage that will fundamentally change how we live on earth.
To stay under two degrees of warming, we may have just two decades to fully transition to a zero-carbon economy—and building new, clean infrastructure takes time. Whatever decisions happen now determine whether we cross a tipping point to climate catastrophe.
In the face of that challenge, Trump wants to prop up the coal industry, build the Keystone XL pipeline, roll back Obama's climate regulations, and cancel the Paris climate agreement.
"The consequences [of canceling the Paris agreement] won't last for four or eight years—they will be felt for many, many, many generations," says Ray Weymann, an astrophysicist and one of 376 members of the National Academy of Sciences to sign an open letter about climate change after Trump advocated pulling out of the Paris accord.
If the U.S. pulled out of the Paris agreement, it would be harder for the rest of the world to move forward (and, because the U.S. is the second largest climate polluter on the planet, would make it very hard for the world to stay on target). Without leadership on climate, U.S. companies are also less likely to get the full economic opportunity of developing clean tech for the rest of the world.
Of course, some changes are already underway—in the U.S., state and city governments are making their own plans to cut emissions, along with utility companies and corporations. So there's a chance that the move to a clean economy could happen without Trump.
"I think we're already seeing this transition underway," says Steven Cohen, executive director of the Earth Institute at Columbia University. "It would be better if the government was pushing it, but the market will do it even if the government doesn't."
There are also some things that Trump can't easily change—Obama's Clean Power Plan, for example, was developed because the Supreme Court said it was legally required under the Clean Air Act. If Trump backed out, he'd have to create another plan that met the legal requirements (or, even less likely, get Congress to alter the Clean Air Act).
Still, to have the best chance of meeting climate goals in a short time frame, it makes sense to elect someone who actually wants to cut emissions now. Even if the market is moving in the right direction, policy does make a difference; electric cars, for example, could become the dominant cars on the road seven years faster with government intervention.
"This is a problem that can be solved," says Weymann. "People sometimes throw up their hands and say, 'Oh, we're doomed.' There are just enormous opportunities for us to solve the problem. What we need is the political leadership to do it."
If Trump were able to implement the economic policies that he wants—from tax cuts for the rich to booting out undocumented workers and adding tariffs on Chinese products—the economy would sink back into a recession.
By the end of his presidency, the U.S. would lose nearly 3.5 million jobs (as opposed to gaining 6 million jobs if today's policies were left unchanged), unemployment would rise, and the stock market would plummet, according to a report from Moody's Analytics.
"Even if he were only in office for a term, the impacts would last a lot longer," says Mark Zandi, chief economist for Moody's. "It would take years, maybe a decade, to get back on track. The impacts would be significant."
There are several reasons Trump's policies would bring the economy down. To pay for massive tax cuts for the rich—plus the additional funding Trump wants for building his Mexican border wall, and for the military—the government would have to take on significantly more debt. Adding tariffs on Mexican or Chinese goods would drive up prices for U.S. consumers (and companies would be likely to move to Southeast Asian factories, not bring manufacturing jobs back to the U.S.). If Mexico and China add their own tariffs on American products, U.S. businesses would lose nearly $85 billion.
If undocumented workers are pushed out, that would cause a labor shortage as baby boomers retire. "The growth in the labor force is going to come to a virtual standstill unless we change immigration law, let alone require millions of undocumented people to leave the country," says Zandi. That labor shortage would also raise prices for consumers.
The analysis also considered what would happen if Trump's policies were adopted, but at a smaller scale, or if Congress forced compromises. Even with a watered-down version of his platform, the economy would still do worse than it would have otherwise.
If the economy slumps and people lose their jobs, that also can have longer-term effects. If parents are unemployed, and kids face food insecurity or the family is forced to move or homeless, they're more likely to struggle in school. Older students may no longer be able to afford college. Kids growing up in poverty are more likely to have lower lifetime earnings, poor health, and are more likely to commit crimes—all effects that last decades.
By some accounts, income inequality is already higher now than it has ever been before in U.S. history; over the last three decades, the top 1% of incomes have risen 279%, while the lowest-earning workers saw an increase of less than 20%. But the gap would become worse if Trump's policies went into effect.
"His tax cuts go almost exclusively to folks in the top part of the income distribution," says Zandi. According to the Tax Policy Center, people who are in the top tenth of the top 1% of income payers would get a cut of $1.4 million a year. The rest of us—the 99%—would get tax cuts of less than $2,500.
That's very different from Clinton's proposals, which would raise taxes for the super-rich by $800,000 a year. "That would have very significant implications for income and wealth distribution," says Zandi.
Over the long term, income inequality is yet another reason that the economy slows down. The farther behind people fall, the less likely their children are to catch up.
A Trump presidency could also make terrorism more likely, because of Trump's impetuous, reactionary personality. "Terrorism is by definition a form of psychological warfare," says David Schanzer, director of the Triangle Center on Terrorism and Homeland Security at Duke University.
"The terrorists, by and large, are too weak to obtain their major objectives through their own actions," he says. "What they're trying to do is to get governments, societies, to overreact to provocations and actually damage their own societies themselves. That's what I would worry about from a Trump presidency, that he would essentially be an easy mark for psychological manipulation."
For example, Trump might respond by constraining civil liberties in the U.S., damaging the country in a way that terrorists wouldn't be able to themselves. His rhetoric makes terrorism more likely over the long term, as well, by giving potential recruits more reason to hate America. ISIS ads have already used Trump as bait.
"If you look at people who support Trump internationally . . . it's really only people in countries that want the United States to fail," says Ian Bremmer, president of the Eurasia Group, a firm that specializes in analyzing large-scale global hazards.
"It's Hungary's Viktor Orbán, it's Kim Jong-un, it's Putin," he says. "If you talk to any of America's allies, even the Chinese, who are no fans of Hillary Clinton, they all desperately don't want to see Trump."
Because Trump makes it clear that he wants America first, allies know that they can't trust him. "Those countries would hedge their relations dramatically away from the U.S.," he says. The U.S. role in setting the global standards for the economy would be in question, as would the role of the dollar.
"It would have a very negative impact on America's economic influence globally, over the long term, well beyond a single Trump administration," he says.