In CNN’s seven-hour town hall about climate change this week, many of the Democratic presidential candidates aligned in their opposition to offshore drilling, support for a carbon tax, and interest in a Green New Deal.

But businessman Andrew Yang distinguished himself by including geoengineering research in his climate plan. The umbrella term encompasses a variety of controversial and not-so-controversial techniques to counteract climate change, not just slow it down. Such efforts could include say, seeding clouds with aerosols to reflect away sunlight or putting giant mirrors into space.

“In a crisis, all solutions have to be on the table. So if you are attacking on one side, you also should be researching various alternatives on the other,” Yang said during his 40-minute town hall session.

Yang, a longshot candidate, is campaigning on a platform of universal basic income, Medicare for all, and what he calls “human-centered capitalism.” He believes that to curb climate change, ramping up clean energy use and cutting carbon emissions isn’t enough. So Yang wants the US to take the lead on geoengineering.

Although the term may evoke images of futuristic weather-controlling satellites and carbon-capture machines that float in the atmosphere eating carbon, Yang believes some these technologies are far from fantasy.In fact, he thinks they're a necessity.

Read More: We're altering the climate so severely that we'll soon face apocalyptic consequences. Here are 11 last-ditch ways we could hack the planet to reverse that trend.

On August 26, Yang unveiled a $4.87 trillion plan to combat climate change. It calls for an aggressive carbon tax, a 100% renewable electricity grid by 2025, a zero-emissions requirement for all new cars by 2030, and a "fully green economy" - meaning net zero-emissions across all US sectors - in just 30 years.

As part of that budget, Yang proposes spending $800 million on geoengineering research as "a means to reverse the damage that we've already done to the environment."

When asked about the extent of his commitment to such technologies during the town hall, Yang responded: "If you look at my plan, of the $5 trillion, a fraction of one of the trillions is looking at geoengineering."

But he thinks the US should get started as soon as possible on that investment.

"If we don't start experimenting with these methods, then someone else will. Let's be a world leader in geoengineering so that we can ensure it's safe and scalable, and that we're in charge of deploying it, should the need arise," Yang wrote in his plan.

space satellite

Foto: In the movie Geostorm, the world descends into chaos after a terrorist hacks a global network of climate-controlling satellites.sourceGetty Images / SVF2

If the US doesn't start driving the geoengineering train soon, a country like China will, he believes.

"We need be leaders in this and organize a global understanding, pooling knowledge and resources [around geoengineering] and make it so individual countries don't make moves on their own," Yang told Business Insider. "Look, in 15, 20 years, China's going to start geoengineering and they're unlikely to ask permission."

Yang's ambitious plan includes giant space mirrors, carbon capture, and cloud seeding

Geoengineering has increasingly been floated in recent years as an option for battling climate change. There are two main types of geoengineering: carbon capture, which - as the name suggests - removes carbon dioxide from the atmosphere, and solar geoengineering, which involves modifying the sky with particles or clouds that reflect sunlight back into space to cool the planet.

Carbon capture is becoming widely accepted as a safe and potentially effective climate-fighting tool, but critics of solar geoengineering argue that the risks of experimenting with the delicate chemistry of atmosphere are too high.

Yang is interested in both types of geoengineering.

Anak krakatau

Foto: When volcanoes fill the skies with sulfur, it causes more sunlight to be reflected away from the planet. That’s where the idea for solar geoengineering comes from.sourceAntara Foto/Reuters

"The reason I'm talking openly about geoengineering is that it seems highly unlikely that we're going to reverse the trend of emissions," he said, pointing out that the US accounts for only 15% of global emissions. "Even if we became extremely aggressive and forward-thinking in terms of our energy consumption, we would still experience the worst effects of climate change if the rest of the world didn't join us."

In addition to carbon capture, Yang supports other technologies that are ultimately reversible if they doesn't work, like shoring up melting glaciers with dirt to prevent warming ocean water from eroding their bases. A recent article in the journal Nature also voiced support for targeted geoengineering efforts to preserve continental ice sheets.

Yang's website states that he's interested in cloud seeding as well. The technology, a way to make it rain by dropping silver ions into the atmosphere, has already been tested by the Chinese and United Arab Emirates governments.

glacier
Foto: If all of Greenland's ice were to melt, it would raise sea levels 23 feet, submerging some coastal cities.sourceReuters/Andres Arce

Additionally, in an interview with Earther, Yang mentioned his enthusiasm for the idea of a giant space mirror that could deflect sunlight back in space. He described a hypothetical "satellite with expandable mirrors" that could be launched into the atmosphere (and brought back to Earth if it proves ineffective).

Yang told Earther that the mirror was among his top geoengineering technology choices, since it's reversible if something goes wrong.

Read More: How a last-ditch 'planet-hacking' plan could keep Earth habitable for longer

However, many scientists are concerned about solar geoengineering experiments because most models predict that after deploying such measures in one location, varying effects could be seen in other spots around the globe.

So even if a failed geoengineering technology were to be reversed, it could have already irreversibly altered atmospheric chemistry or damaged the ozone layer.

If China take the lead in geoengineering, it could trigger war

Ultimately, Yang is pushing not just for the US to invest in geoengineering, but for world leaders to unite around it. In addition to combatting the climate threat, Yang wants to ensure that countries like China don't get to call the shots decades down the line.

"Imagine a country like China 25 years from now who is going to be bearing the brunt of climate change in the same way that we are. They're not very consultative." he said during the town hall, adding, "I would convene a geoengineering summit and get countries from around the world to make sure that we don't have rogue actors just going off on their own."

geoengineering cover

Foto: Opponents of geoengineering say it could eventually lead to military use of weather-altering technology.sourceShutterstock

China is a likely candidate to initiate geoengineering projects, Yang said, because "they have the money, resources, and public-health stake in the problem."

He added that if the US lets China start atmospheric modifications first in a rogue manner, he expects the worst.

"I believe it could lead to war," he said. "If 15 years from now, China is launching sulfur clouds into the atmosphere, and they float over the ocean and wind up affecting the US, that could be taken really negatively."

Yang isn't the only one who views geoengineering as an avenue for potential conflict: Alan Robock, an environmental-science professor at Rutgers and geoengineering expert, has also expressed concern about what might happen if a rogue country goes ahead with an atmospheric-transformation project.

A conflict over unintended consequences of geoengineering could escalate to nuclear war, Robock previously told Business Insider.

Yang thinks other presidential candidates will come around to geoengineering

Yang doesn't see geoengineering as a replacement for phasing out fossil fuels, instituting a carbon tax, and doing all we can to curb emissions (including remaining in the Paris agreement). He just thinks it should be part of the solution. And he believes other presidential candidates will come around on this.

"Many candidates will join me. People looking will see that climate change trends are getting worst," he said. "And while we can slow the rate that they're getting worse, we won't slow them all together, so we inevitably will start thinking about what more we can do."

Dark clouds hang over the city with its bank buildings in Frankfurt, Germany, on a windy Thursday morning, March 7, 2019. (AP Photo/Michael Probst)

Foto: sourceMichael Probst/Associated Press

Yang said the easiest way to start looking into geoengineering more thoroughly would be to authorize a relatively modest amount of money to fund research.

"You don't need a massive grant to make a huge difference," he said.

He also wants to fund small-scale pilot studies and invest in real-world implementation of carbon-capture and solar geoengineering technologies.

But Yang has a long way to go before cloud seeding or giant space mirrors could hit the policy docket, though eh remains optimistic.

"I'm the man to beat Trump in 2020," he said.