Should we dim the sun to help curb climate change?

The 360 ​​shows you different perspectives on the most important stories and debates of the day.

What is going on

Late last month the White House released a report cautiously calling for more research into one of the most debated theories for fighting climate change: partially blocking the sun to cool the planet.

While it sounds like something straight out of science fiction, interest in what is known as solar geoengineering has increased in recent years as scientists have become more pessimistic that humans won’t reduce carbon emissions in time to avoid potential catastrophic impacts of climate change.

Solar geoengineering involves a variety of techniques to reflect certain amounts of sunlight so that less heat reaches the planet’s surface. The most promising potential approach, according to the scientists, would involve using aircraft to release reflective particles into the upper atmosphere to bounce a small amount of sunlight back into space before it reaches Earth.

The researchers are reasonably confident that solar geoengineering could work. Massive volcanic eruptions over the last century or so have served as natural experiments demonstrating that reflective aerosols can significantly reduce global temperatures. But concerns about the potential risks of tinkering with Earth’s natural processes have meant that no known real-world experiments in man-made solar geoengineering have ever been conducted other than the weather balloons released by a startup in Mexico earlier this year. , a stunt that inspired the country to ban all research on the subject within its borders.

Because there is debate

Since solar geoengineering would not remove any carbon from the atmosphere, no one argues that it could be an alternative to transitioning to green energy. At best, it is seen as a means to temporarily stave off the more dire weather effects of climate change as the world makes the long and costly effort to decarbonise the global economy.

A group of prominent climate scientists has called for a worldwide ban on solar geoengineering research, arguing it poses an unacceptable risk to the climate. They worry about the potentially catastrophic side effects that could occur if humans start tinkering with the climate, the risks of conflict that could arise if nations start competing to improve their climate at the expense of their neighbors, and the danger that geoengineering could be used as an excuse to slow down or abandon the green energy transition.

The story continues

But proponents say these hypothetical risks pale in comparison to the catastrophe experts say will happen if we don’t take action to stop the Earth from continuing to warm. They argue that simply cutting emissions won’t be enough to avert the worst, and scientists can’t understand all the risks of geoengineering unless they are allowed to conduct experiments on it in the real world.

Perspectives

SUPPORTERS

Going green will not be enough

Pretending that climate change can only be solved by cutting emissions is a dangerous fantasy. David Keith, professor of applied physics and public policy at Harvard, to the Guardian

Scientists cannot understand the dangers of geoengineering unless they are allowed to research it

It’s so late in the climate fight that a little solar geoengineering might be a good idea. We won’t know, unless scientists can do the hard work to find out. Gernot Wagner, Washington Post

We need to buy time for decarbonisation to work

In the event that human-caused warming turns out to be much faster than currently projected, installing a stratospheric sunscreen would provide humanity with more time to develop and implement low-carbon energy technologies and devise ways to reduce the extra carbon dioxide in the atmosphere. Ronald Bailey, Reason

SKEPTICS

Geoengineering will not save us and may distract us from what it actually can

While solar geoengineering can help divert heat and improve weather conditions on the ground, it’s not a long-term solution to climate change. It sends a message to the world that we can continue to consume and pollute excessively because we will be able to engineer our way out of the problem. Chukwumerije Okereke, New York Times

The potential side effects could be worse than anything climate change could do

There is no shortage of potential unintended consequences. For one thing, some areas of the planet, like the tropics, could overcompensate and get too cold while other areas, like the polar regions, would hang on to the heat. Messing with the atmosphere could also mess with natural climate systems. Mirjam Guesgen, Deputy

Any science that gives nations such immense power would inevitably lead to conflict

Who would be responsible? Which country can decide when the sun will be blocked, to what extent the sun’s rays will be blocked and for how long? Who gets the divine power to decide where on Earth the sun will continue to shine and which regions will have their sunlight taken away at any given time? Tom Wrobleski, SI Live

The dangers of climate change are no excuse to take dangerous risks

Just because we’re desperate doesn’t suddenly make solar geoengineering a good idea, because the risks are so immense. Lili Fuhr, environmental law expert, on CNN