It’s time to delete carbon from the atmosphere. But how?

Enlarge / We need less of this. (credit: Getty Images)

This week and next, government representatives are gathering in Glasgow for the United Nations Climate Change Conference, or COP26, the latest of an increasingly frantic string of meetings as humanity runs out of time to drastically reduce our greenhouse gas emissions. Everyone agrees that carbon is bad. And everyone agrees it’s hard to get rid of; carbon dioxide lasts up to 1,000 years in the atmosphere. The world even has a common goal: keeping global temperatures from reaching 1.5 degrees Celsius above pre-industrial levels, the boundary set by the Paris Climate Agreement.

But nations don’t agree on how we’ll get there: staving off the worst of climate change will require cutting carbon emissions and developing ways to pull them out of the atmosphere. Here are some of the options delegates will likely be discussing as COP26 continues.

The problem with net zero

You’ve probably heard of a sticky little concept known as net-zero emissions: if you put any carbon into the atmosphere, you have to take the same amount out. On Monday at COP26, India’s prime minister, Narendra Modi, announced that his country would reach that goal by the year 2070. Earlier this year, President Joe Biden said the United States would do the same by 2050, a goal the UK has also pledged to achieve.