>There is plenty of evidence that we can still avert the worst of it without resorting to geoengineering.

And zero evidence we will...

This kind of defeatist attitude doesn't help with the situation at all. We can all do our part in reducing our daily carbon emissions, raise awareness, and educate policymakers and business stakeholders on the importance of mitigating climate change!

Consider me a policy maker.

I want to know what the costs[1] of ignoring are likely to be so I can be sure it's worth the pain to ban non-electric cars in 10 years, ram through nuclear power plants while gutting safety regs so we can get them built in less than a decade and try and threaten India and China into reducing CO2 emissions. What do you tell me?

[1] In $, convert other units like lives into dollars as need be and be sure to value lives from different culture lives at 0.1x as thats the expressed preferences of the population based on chatitable giving figures.

You can call it defeatist, but at this point it's factually true. We've made a negative amount of progress on this matter. And that's taken 40 years. We have very little time left. We have already locked in almost 2 degrees of warming.

These are all regrettable facts. But that are facts.

40 years of raising awareness and individual action has failed.

One man's defeatist attitude is another mans realistic attitude. Does it help? No, it doesn't. But for the defeatist and the realist alike that may no longer matter. I'm 'long' on humanity, but I'm not convinced we will be able to avert the looming (and for some already very present) issues. My feelings are in part because of how we dealt with COVID-19, if a pandemic can't get us to pull the cart together then nothing can.

It's important to understand that reducing carbon emissions doesn't cool the planet. It only makes the future warmup slower.

> There is plenty of evidence that we can still avert the worst of it without resorting to geoengineering.

We already have once in a lifetime climate event every month and the carbon locked-in of the past decade still hasn't kicked-in. I'd argue the complete opposite, there's a lack of evidence of other options.

Why exactly do you place faith in evidence that says "we can still avert the worst of it" and are not willing to do the same for evidence that says "we can do even better with geo-engineering"? Presumably the scale of the problem is the same either way, so well-reasoned evidence should be able to persuade you of either.

> You have absolutely no idea if the "solutions" we try won't lead to even worse outcomes.

This is absolutely untrue.

The mechanisms of how SO2 in the stratosphere cools the planet are well understood and empirically observed.

This includes the fact that it breaks down in ~2 years, making it self repairing, should something unforeseen happen.

what is this now, a quadruple negative?

It is untrue that they have no idea if the "solutions" we try won't lead to worse outcomes

It is true that they have some idea that the "solutions" we try won't lead to worse outcomes

It is true that they have some idea that the "solutions" we try will lead to better outcomes.

I think the nuance needed here is: what do we mean by "better outcomes?" It's reasonable to believe that it will help lower temperatures. But is that an "outcome" in and of itself?

If we consider the "outcome" to also include the second and third order effects, I'd like to understand how anyone could be certain that it will be better.

> In the early 1990s, anthropogenic sulfur dominated in the Northern Hemisphere, where only 16% of annual sulfur emissions were natural, yet amounted for less than half of the emissions in the Southern Hemisphere.

> Such an increase in sulfate aerosol emissions had a variety of effects. At the time, the most visible one was acid rain, caused by precipitation from clouds carrying high concentrations of sulfate aerosols in the troposphere. At its peak, acid rain has eliminated brook trout and some other fish species and insect life from lakes and streams in geographically sensitive areas, such as Adirondack Mountains in the United States. Acid rain worsens soil function as some of its microbiota is lost and heavy metals like aluminium are mobilized (spread more easily) while essential nutrients and minerals such as magnesium can leach away because of the same. Ultimately, plants unable to tolerate lowered pH are killed, with montane forests being some of the worst-affected ecosystems due to their regular exposure to sulfate-carrying fog at high altitudes.[1]

Sure, let's have ~2 years of that.

[1] https://en.m.wikipedia.org/wiki/Sulfur_dioxide

The way to do it is to release the SO2 directly into the stratosphere, where it stays for ~2 years, and does not affect rain, which happens far below.

One of the risks of a strategy like this is that we become reliant on it and use it as an excuse to solve the actual problem slower. Then if there's ever any disruption to SO2 production we get 20 years of warming all at once that we otherwise might have worked to avoid.

Betting on never having a disruption to that supply seems high risk to me.

Ending fossil fuel usage and removing the excess CO2 will take at least 50 years.