The climate crisis is the result of a century of humans emitting climate-forcing pollution (carbon dioxide, methane, soot) and cutting down trees unsustainably. The real solution must be to stop these practices. However, even if we stopped these today the climate would warm for many decades, resulting in the loss of reflective ice sheets and the release of frozen methane – accelerating the warming. We will need emergency cooling strategies for the planet in the coming decades- and this is where “Geoengineering” or “Climate Engineering” comes in. Wikipedia has a good, general discussion of the issue, including the controversies, which are really important! The major national research academies of the US and Britain have looked at this and concluded: it is risky but we need to do research on this now.
Let me be clear, there are many things we should do before we do climate engineering. We should consume less, use energy more efficiently and use clean energy – in that order – before doing any form of solar radiation management. We should stop degrading forests. And to make all this happen, we need a large price on carbon now. I think 95% of our efforts to address climate change should go towards these things. But we are NOT doing these things globally and time is running out.
I believe that Marine Cloud Brightening may be among the least dangerous forms of climate engineering because the effects of atomized seawater are not long lasting and they are relatively local. This makes it a good place to start, slowly, to apply local cooling at the most at-risk marine environments. Possibly the first place this can make a difference is in reducing damage to the Great Barrier Reef of Australia. There are many cloud and climate science questions to be addressed, but there is also a big mechanical engineering challenge: producing aerosol particles of the correct size distribution with a technology that requires relatively little energy and can be scaled massively. This is the challenge we are taking on to help the Australian team. We will continue the work of Cooper et al, bringing some new atomization techniques to the mix and supporting atomizer design using computational fluid dynamics.