Scientists to focus on geoengineering

As the window we have to limit global warming to 1.5C starts to close, many scientists and politicians are turning their attention to ‘‘climate overshoot’’. They want to better understand the implications of shooting past the emissions reduction targets countries set themselves at the Glasgow climate conference. We must cut global emissions by 43% by 2030 compared to 2019 levels, just to have a shot at staying within the 1.5C warming threshold.

The realists assume we won’t get our act together in time and are looking at Plan B. They include a group of eminent global leaders who have formed the Climate Overshoot Commission to examine what we’ll need to do to adapt to 2C or more of warming.

They are also looking at the potential for geoengineering schemes to act as a technical fix to reduce global temperatures. Solar geoengineering, which can involve seeding clouds or spreading sulphur particles in the atmosphere to reflect sunlight back to space, is considered the most promising method.

Geoengineering is considered difficult and scary, so we haven’t funded large studies to explore whether it’s a realistic option.‘‘All of the ways by which we can alleviate this risk [of climate overshoot] must be evaluated,’’ Pascal Lamy, the former head of the World Trade Organisation and a member of the Climate Overshoot Commission, told the Guardian last month. ‘‘I think a global effort on geoengineering could work.’’

Scientists are coming to the same conclusion. The American Geological Union last week said it would form ‘‘an ethical framework to guide the research and possible deployment of climate change intervention measures’’.

It wants to work with global bodies to develop some sort of governance overseeing geoengineering experiments and the use of the technology. It doesn’t give geoengineering the green light but at least we are now taking it seriously.

Some climate scientists argue that by doing so, we water down the urgent case for cutting emissions. But there’s nothing to stop us from pursuing deep cuts now while we also research whether geoengineering has legs.

‘‘If we put off research until the 2030s, we could find ourselves in a world that’s made some uneven progress on the reduction of greenhouse-gas emissions but not enough, with temperatures still headed towards 3C of warming,’’ the environment and sustainability professor and author Holly Jean Buck points out.

That’s not an unrealistic scenario. I want the world’s best minds focused on all the options we have to deal with it.