Earth is warming faster. Scientists are closing in on why (2024)

> Wait... So, to undo it all we have to do is stop doing it? Doesn't this contradict the statement right before it?

It's not quite that simple.

The intuition that you're subtly relying on is the idea that the response or effect of one of these geoengineering treatments is linear. But unfortunately, that's not something you can assume about a dynamical system. In reality, the climate system can undergo certain types of hysteresis where "undoing" the forcing doesn't revert the initial perturbation, because you're suddenly on a different response curve. Probably the most famous example of this in climate dynamics is the way that the ice-albedo effect sets up a hysteresis in the trajectory towards a "snowball Earth" scenario. Apologies for the lack of links/references; Wiki has decent write-ups on this, and it's typically covered in the first chapter of a climate dynamics textbook.

The potential response to suddenly stopping a climate change mitigation strategy has a very well-popularized name: a "termination shock." In fact, Neal Stephenson used exactly this concept in his titular novel on the topic in 2021.

As a climate scientist, my mental model to better understand the risk of termination shocks and unintended consequences boils down to how fast the response of the climate system is. Marine brightening is "less risky" because the meteorological response to these interventions is extremely fast; a cloud-precipitation system will respond on the order of minutes to hours, and unless the intervention continues unabated, it will clean the air quickly, limiting the repsonse. Stratospheric aerosol injection is more complicated, but we have a very good analogue - very large scale volcanic eruptions like Mt Pinatubo. The response to these sorts of events is measured more on the timescale of 2-5 years, although knock-on effects (such as a shift towards more diffuse solar radiation reaching the surface, which has significant effects on terrestrial and oceanic biogeochemistry) could very much persist longer than that - and don't "snap back" nearly as quickly. A continuous, Pinatubo-like intervention would compound and introduce coupled atmosphere/ocean responses that could decade years or longer to fully play out. And that's _in addition_ to the near immediate (1-2 year) response in global average temperature, which would bounce back to most of the pre-intervention level very quickly.

These things are complex. There's a lot we don't know. But, there's also a lot we _do_ know. I would encourage anyone who does not have significant experience in climate dynamics to remain curious and avoid jumping to conclusions based on simple intuition; they're probably wrong.

I have always found the American perspective on this subject annoying precisely because of the crazy emissions and consumption per capita in the US.

It feels like US citizens intentionally or not gatekeep wealth, and do nothing policy-wise about the unsustainable consumption patterns besides going to war for oil.

No serious attempt to increase transit ridership, no serious attempt to electrify the automotive industry, no serious attempt to build a domestic renewable energy production pipeline, no serious attempt to curb suburban sprawl, no economic disincentive on single use items like fast food packaging, no serious effort to move public health education toward healthy low carbon diets (less red meat, less dairy from cows), no corporate-level disincentives to waste (e.g., companies throwing out returned items when it’s cheaper), no serious effort to move to high efficiency construction and HVAC practices.

The list goes on and on. In the American perspective other counties like China are at fault for everything despite being the world’s foremost consumer of resources and one of the biggest ideological sticks in the mud for progress.

Could you cite one source that would consititute an example of such reading?

there is absolutly no possibility of injecting enough of anything into the atmosphere in such a way as the CO² cost of doing so dosn't cause more heating than the "airosol" reflects into space, which in itself is purely conjectural, there bieng, absolutly zero engineering paractice or experience to go from,.... well, not counting an unlimited supply of hubris

If you don’t know how to find scientific journal articles then you are too far behind for me to help with.