Na va-nad

On The Climate Brink, Zeke Hausfather writes:

We are already geoengineering the planet today, but badly. Humans are cooling the climate today by emitting 75 million metric tons of sulfur dioxide into the lower atmosphere, almost entirely as a byproduct of burning fossil fuels. This cooling offsets about 0.5C of warming that would have otherwise occurred from CO2 and other greenhouse gases, but it comes at the cost of millions of premature deaths per year caused by the sulfate aerosols.

I like the sentence “we are already geoengineering the planet today“, which is what I argue in Solar Geoengineering via SRM (Solar Radiation Management). Here, Zeke Hausfather singles out only the fact that humans do generate negative radiative forcing as a matter of routine – albeit in a way which is harmful to their respiratory health -, in order to argue in favor of doing that same negative forcing in a less harmful way. Whereas I like to argue that it is legitimate to do as much negative forcing as we do positive forcing.

Of course the specialists will say that it’s not as simple as that (how do we know exactly how much is “as much”, plus it’s not exactly push and pull, it’s the Earth’s complex climate physics and chemistry…) but I still believe that there is no reason to limit solar geoengineering to the amount of negative forcing that we happen to be generating today (or say, at the level we were doing it in 1970). No one asks for permission to emit a little more CO2, no one asks for permission to pave a new road with asphalt. Does anyone whine about too many trees being planted, too many fossil fuel power plants being replaced by renewables, or too many roofs being painted white? In the absence of (a) stability in the planet’s climate and (b) an established framework preventing anthropic activities impacting the climate, I don’t see why negative forcing would be regarded more harshly than positive forcing.

“What if someone decided suddenly to cool the planet by 6°C? What if everyone / every country did whatever they pleased? It would be chaos!” Of course, agreement, regulation and control are better that chaos, and we – the humanity – will be better off when we get back to a stable climate with good understanding and good control over anthropic activities that would modify it if not balanced. But right now I see the over-cautiousness regarding solar radiation management in general and SO2 dispersion in the stratosphere in particular, as totally out of place.

If it were only up to me, I’d start with half a Mount Pinatubo this year, and increase progressively to a Mount Pinatubo per year over the coming ten years! 😆