For a long time, the idea that we could reverse some of the effects of climate change with ambitious techological interventions has been anathema to many in the climate movement.
These schemes -- generally lumped under the term 'geo-engineering' -- can include projects such as spraying particles in the upper atmosphere to deflect heat from the sun; building millions of machines to 'suck' carbon dioxide from the atmosphere, or dumping certain chemicals in the sea to reduce ocean acidification caused by greenhouse gas emissions. Some people even imagine building giant mirrors or shields to deflect the sun's rays.
People trying to convince big polluters to stop burning fossil fuels don't tend to like these schemes because they think they represent a kind of 'get out of jail' free card. The fear is that companies or governments could turn round and say: "We don't need to stop burning fossil fuels because we can just figure out a technical fix for the climate. So let's carry on with business as usual."
That's a legitimate concern -- it's obvious from a slew of scientific reports published in the past year that if we don't drastically reduce emissions, then we could render Earth uninhabitable.
But even if we stopped burning fossil fuels this afternoon, there's still so much warming 'baked-in' to the climate system that entire socities in the global south may be wiped out. These people have already been feeling the impacts of climate change: which is partly why so many migrants are fleeing Africa, the Middle East, and central America. If we have a technology that might buy these people a bit more time, then we should use it.
The other big objection to geo-engineering -- particular the idea of spraying particles into the atmosphere -- is that people think they could have unintended consequences. Imagine if the layer of particles we sprayed into the sky didn't defllect the sun, but actually trapped more heat, tipping us into a truly hellish future.
But maybe those fears are overblown. After all, scientist have found that volcanic eruptions have a natural cooling effect by throwing trillions of particles into the upper atmosphere. It would be fairly straightforward to develop technology that would allow us to simulate an eruption every year to keep the temperature down.
For sure, we need more research. But initial studies are promising, as this Guardian story from earlier this month suggests: https://www.theguardian.com/environment/2019/mar/11/solar-geoengineering-climate-change-new-study?CMP=greenlight_email
It's time to be realistic: global warming is here. Yes: we need to urgently cut emissions. But we also need to explore every possible tool in the box that might save the lives of millions of people in the global south whose are already paying the highest price for climate change.