It’s not that climate change isn’t real, or even a question of whether human activity is the root cause. But faced with a solution which doesn’t require massive societal change of a particular sort, the solution is rejected out of hand.
Just because it doesn’t force a specific set of political changes which up until now have been punctuated by the threat of nothing less than Armageddon,... we cannot actually reject a cheap solution that takes Armageddon off the table, just because it may make the other goals harder to accomplish.
It is morally unacceptable to let the Earth burn rather than be left to solve issues of pollution and clean energy independent of the almost unfathomable toll of a 3°C future. That to me is frankly an untenable position when you contemplate the actual number of lives in the balance.
But you're right that The Climate Change Movement™ dismisses these things out of hand. This is because it is only incidentally about combating climate change. It is primarily about giving more power to approved politicians and bureaucracies. This is also why we have made no almost progress on the underlying issues. We were never meant to.
We should be skeptical of any ways to address climate change that rely on technology and require very little behavior change.
Burning fossil fuels does more than just warm the planet, so trying to stop the planet from warming through some far out means wouldn’t address these other huge issues. Also, the easiest path to haunting climate change is to literally stop doing the damaging things.
Exxon, a big oil corporation, had accurate predictive models of climate change, agreeing with scientific consensus, already in 1982 and confirmed "it will cause dramatic environmental effects before the year 2050". https://twitter.com/i/status/1187719206562910209
Shortly after Exxon began to deny global warming and started "greenwashing" marketing campaigns, which today show up directly in the news articles on global warming, e.g., in The New York Times: https://twitter.com/status/1187435336185581570
1. The single cheapest and quickest way to make a difference is to - en-masse - moderate our behaviours. But guess what? People are so wedded to their monster-truck-driving, plastic-consumable-disposing, distance-product-shipping, holiday-air-travelling lifestyles that they won’t (on the whole) bear even the slightest personal “burden”. The relatively moderate costs associated with behaviour-modifying policies (eg a carbon price), are vehemently and successfully opposed (or neutered) by governments all over the world. And the reason they are free to do so is because there’s no political cost to doing so. Given all that, why on earth would anyone think it’s going to be politically acceptable to fund even costlier and potentially fraught geo-engineering responses?
2. Shades will do nothing at all for the ongoing acidification of the oceans and the consequent marine species destruction.
The cheapest and only long-term sustainable solution is to massively reduce the global population. Say we manage to massively transform society and half the average person’s ecological footprint. All that effort will be for nothing if we’re doubling our population in a couple of decades anyway. Any effort to modify our behavior will be pointless if we keep outbreeding the gains we make. By contrast, if we simply reduce the birthrate by a factor 10-100 we can drastically reduce our impact on our environment without any other changes.
Any other measure is just a stop-gap until we acknowledge the inconvenient truth: humanity is a plague. We’re breeding like cockroaches and if we don’t stop it we are doomed, regardless of any other measures taken.
I am very much a technology optimist. I believe that technology is the route to providing sustainable solutions across the board in energy, transportation, agriculture, and materials. Even more, I believe that the only solution is for technology advances to make the sustainable solution to be the preferred solution. When going green is also cheaper, faster, better, then everyone goes green by default.
The role of government here is to align incentives and subsidize market-driven R&D efforts which result in technologically superior products that also happen to be sustainable which can win in a competitive marketplace on their own merits. The perfect example of this is EVs. EVs will totally supplant new ICE vehicle sales in the next couple decades because they will ultimately be a better vehicle in every possible metric.
I think we are seeing the same effects in terms of renewable energy that can now compete on cost even without subsidies, and we are in the beginning stages of where we need to go with agriculture (I'm sure actually much progress has been made, but I'm less familiar with that tech).
From a materials science perspective, we need better alternatives for clothing fibers, and better alternatives for plastics in our products and packaging. Cotton is biodegradable but takes far too much water to produce -- possibly something that further genetic modifications to cotton could reduce. Plastic blends in textiles are great for performance, but end up as microplastic in our waterways and oceans. The alternative isn't that everyone is going to switch to hemp. The alternative must be a better material developed that provides superior performance, longevity, texture, carbon footprint, and ultimately clean disposal or recyclability. Government's role is to align incentives for this R&D to occur by taxing externalities or subsidizing new products that present lower externalities.
As to the queston of controlling the effects of increased CO2, one of which is global warming, and another of which is ocean acidification, I think we will come to a point where we need ways to effectively reduce atmospheric CO2 independently of efforts to reduce CO2 emissions, and technology will ultimately afford us that.
I think it's an open question whether the timescale over which atmospheric CO2 may ever be brought back below, e.g. 300ppm, will require engineering a more direct solution to both ocean acidification, and global warming. Even if tomorrow anthropogenic CO2 emissions dropped to zero, how long would that even take? Solar shields and atmospheric CO2 extraction are technologies that warrant future research and discussion.
The real obstacle is the confusion in the public opinion spurred by big oil marketing and lobbying. It's really hard to find quality information online, but it exists since many years and it's pushed down on purpose by interest groups. Here is an example:
Exxon, a big oil corporation, had accurate predictive models of climate change, agreeing with scientific consensus, already in 1982 and confirmed "it will cause dramatic environmental effects before the year 2050". https://twitter.com/i/status/1187719206562910209
Shortly after Exxon began to deny global warming and started "greenwashing" marketing campaigns, which today show up directly in the news articles on global warming, e.g., in The New York Times: https://twitter.com/status/1187435336185581570