If some things "are irreversible on timescales of centuries to millennia" then really just going carbon neutral etc. sounds like a pretty weak approach as it would create costs now and large benefits only far in the future. Maybe this really needs geoengineering (and more spending on mitigation)?
Has any means of geoengineering been demonstrated as feasable?
Given our track record, it would probably be best for us to scale back our consumption while promoting re-forestation. Nature can likely heal itself far better than our wildest geoengineering ambitions.
Yes, but it doesn’t mean carbon capture. The Netherlands cannot exist without geoengineering and more and more places are going to have to be building dikes and sea walls as flooding becomes a problem.
Desalination would become more and more prevalent as we are dealing with droughts and we will likely have to engineer forests to be more resilient to forest fires by creating more and more clearings and other barriers to serve as firebreaks as well as planting new forests that may be less inducive to forest fires.
Those examples are more conventionally considered "engineering" or "forest management." They are smaller-scale projects typically involving regional adaptation to adverse weather/climate.
Geoengineering is a bit different, typically on a larger scale:
> Climate engineering or commonly geoengineering, is the deliberate and large-scale intervention in the Earth's climate system.[1] The main categories of climate engineering are solar geoengineering and carbon dioxide removal.
When you’ll need to do things on a global scale such as a sea wall that would say protect the eastern coast of the US it would definitely fit into geoengineering.
By this definition a small scale carbon capture process that is borderline effective is considered climate engineering but managing 1000’s of km of dams and dikes isn’t.
I am just asking whether geoengineering has been demonstrated as a feasible solution to reverse trends of global warming and anthropogenic greenhouse gas emissions.
Geoengineering proposals typically aim to reduce the global greenhouse effect through several hypothetical means (like increasing cloud albedo.)
Dykes and dams that curtail flooding of coastal regions can be monumental undertakings but aren't typically referred to as "geoengineering." Hydropower from a dam could be a good way to reduce carbon emissions, but again wouldn't be considered geoengineering.
Clearly feasible, as demonstrated by anthropogenic climate change. Going back to a different life style is an option, but will be strongly opposed by a lot of people (and not without justification).
Planet was much hotter, much colder etc. So as a species we need to learn to cope and tackle this anyway, why not start now?
Almost everything humans do at scale interacts with the environment. The perspective of just not interacting with the environment anymore is a fantasy. We need to learn to wield the environment skillfully, instead of clumsily waving it around. We cannot just "stop" having an effect on the environment.
Nobody is proposing we "not interact with the environment anymore." That is a straw man.
The idea is to mitigate our impact on ourselves and the environment by reducing consumption. We already have widespread understanding that reduction of resource usage is the most environmentally beneficial change we can make.
I didn't mean it as an attack specifically on the parent comment, sorry if it came across that way. What I mean about the perspective "not interact with the environment anymore" is that many/most people describe the environment as something that exists above and around us. Something that is best left undisturbed and interacted with as minimally as possible by human life.
I am proposing that this perspective has run its course. It is clear that human behavior can have a very broad impact, so we should aim to learn to work with the environment for the better.
This means learning how to intervene on "natural" (whatever that means) environmental processes such that they tip in our favor (ecological engineering).
That depends. Is it too unnatural to go and plant millions of trees? What about culling populations of deer (as we do here in Scotland) to prevent the erosion of forestry (deer love to graze on saplings)? What about the introduction of new species to restore ecological balance? These things work when we get them right. I'm proposing that we get better at it, instead of giving up.
Weather should be very controlable by how much sun hits the earth. Which then causes heat, wind, water evaporation etc etc.
Large sun screen satelites (very simple ones that can fold out foil origami style) could block out a lot of sun at places according to stabilization weather models. Same for reflector sattelites, which could add more sun in specific places.
The difficulty is that we cannot send a hundred thousand sattelites out of our gravity well. We would need to setup basic mining and manufacturing on the moon for this plan to work (you can send sattelites into earth orbit at almost zero cost).
The time it would take to setup a factory on the moon should also be used to develop the necessary weather models, which should then be tested out very slowly with the first few thousands of sattelites.
Altering albedo alone still leaves us with ocean acidification problem, but I'm not up-to-date with the risks of that (other than coral reef dying out, which is absolutely tragic).
Mitigation spending will happen anyway, the focus rightfully should be on minimizing the need for mitigation. By all accounts mitigation costs more than carbon reduction, it is just spent later on. I suppose it all comes down to how much of the problem our generation wants to kick down the road.
As for geoengineering. If you mean adding particles to cool the atmosphere, then this is a mitigation strategy (it doesn’t reduce carbon, just compensates for it). I think we need to research this to have a plan B, but it is kind of a desperation move, and quite risky, so I wouldn’t consider it smart to have it as plan A.
Not sure I understand your mitigation point: If it is already too hot in some areas or flooding gets extreme, people living there would probably want mitigation now, not later. And if this just happens in ten years, also need to start thinking about mitigation now.
