A civil war is brewing in the climate and cryosphere community. There is a group of scientists, engineers (and funders) that are really starting to push forward on geoengineering approaches to mitigate the impacts of climate change. 1/

One of the more advanced ideas is that we can eject particles (aerosols) into the stratosphere and these will reflect solar radiation. This can reduce the temperature of the planet because we get less solar radiation at the surface.

There is also a growing push to develop infrastructure that can block warm water from the bottom of ice shelves and glaciers so that we reduce bottom melt with the idea that this might reduce #SLR rise. 2/

One argument is that we are already entering dangerous climate territory and these “interventions” might reduce risk, at least in the short term. We are in a climate emergency and need to look at all options. 3/

There is a good argument that there is a lot that we don’t know and we need to invest in research into these ideas to better understand the uncertainties and tradeoffs. Somebody is eventually going to try it anyways. 4/

There are a lot of problems with these arguments. A lot of the arguments revolve around risk and governance. If you invest in these strategies do you delay efforts to reduce emissions? How do we actually get consent or establish international governance for these methods? Who decides? Who benefits? 5/

But to me the biggest argument against is that geo-engineering is simply not a significant part of the solution. Geo-engineering won't work and we already know why. 6/

There is no way that any of the geo-engineering solutions will be successful unless we rapidly reduce our emissions. If you don't reduce emissions, you need to build bigger and bigger platforms to block the water. You need to inject more and more aerosols. No more blue skies. It gets hotter and hotter. 7/

And the lifetime of CO2 in the atmosphere is long. So we are committing ourselves to these interventions for centuries. Longer. That means international cooperation between the United States, Europe, China, Russia and everyone else for generations. What part of that seems like a reasonable approach? 8/

I don’t think that people in the cryosphere and climate communities fully understand the geopolitical risks or the fact that once the technology to do these "climate interventions" exist the technology will be deployed.

I don’t think that people realize that we aren’t that far off from seeing tests and eventually deployment of some of these technologies. 9/