Paris climate goals mean emissions need to drop below zero

If governments are serious about the global warming targets they adopted in Paris, scientists say, they have two options: eliminating fossil fuels immediately or finding ways to undo their damage to the climate system in the future. The first is politically impossible — the world is still hooked on using oil, coal and natural gas — which leaves the option of a major cleanup of the atmosphere later this century. Yet the landmark Paris agreement, adopted by 195 countries on Dec. 12, makes no reference to that, which has left some observers wondering whether politicians understand the implications of the goals they signed up for.

I would say it’s the single biggest issue that has to be resolved.

Glen Peters of the Cicero climate research institute in Oslo, Norway

Scientists refer to this envisioned cleanup job as negative emissions — removing more greenhouse gases from the atmosphere than humans put in it. Right now we’re putting in a lot — about 50 billion tons a year, mostly carbon dioxide from the burning of fossil fuels for energy. There are methods to achieve negative emissions today, but they would need to be scaled up to a level that experts say could put climate efforts in conflict with other priorities, such as eradicating hunger. Still, if the Paris climate goals are to be achieved, there’s no way to avoid the issue.

My view is, let’s have this discussion. Let’s involve ourselves in developing these technologies. We need to keep learning.

Jan Minx of the Mercator Research Institute on Global Commons and Climate Change in Berlin