Just to add that the majority of geoengineering methods currently proposed - particularly those that reduce absorbed solar radiation (such as stratospheric sulfate and marine cloud brightening) come with some significant side-effects.
Many proposed geoeningeering methods don't treat the problem but just mask the symptoms. For starters, CO2 heats the surface and the atmosphere, but solar radiation primarily heats the surface.
This means you cannot use a reduction in incoming sunlight to fully offset CO2 warming - if you get the surface temperature correct, the atmosphere is still warmer and so you get less rain. For many regions, a reduction on rain might be more important - we wouldn't want to end up killing the Amazon rainforest by accident!
> I’m imagining sulphates being something to do with it
In a roundabout way they do. Back in the 70s-90s, sulphates were being pumped into the atmosphere in huge amounts due to fossil fuel combustion and other industrial processes. This was reacting with atmospheric water to produce hydrogen sulphate, otherwise known as sulphuric acid, which caused acid rain.
The fix was not some grand geoengineering scheme, rather it was to implement a cap and trade system, much like what has been proposed for CO2. The result is that SOx emissions dropped precipitously, thus acid rain in the United States is a thing of the past.
That's the real solution. To limit CO2 emissions. We know this, the world knows this, the people making money off the fossil fuel industry know this, the politicians they own know this. Yet here we are talking about spraying more shit into the air we breath because that's the easiest option that doesn't disrupt profit or inconvenience anyone.
Except of course that things are becoming ever more problematic in the natural cycle as well. The water supply in the Indus Valley, for example, does not support even 10% of the people living there. This issue will turn critical (ironically it will turn critical faster if global warming stops) in the next 100 years, maybe faster. They'll run out of water to grow crops, and they're sure as hell not going to be importing much food.
Oh and if you're hoping for a political solution. 95% or so of Bangladesh lies in the Indus valley. You'll have to explain to 150 million people, first, that they'll all have to move and that they'll no longer have any political power at all, anywhere. The country will, essentially, die. Oh and the only places they can move are India, hostile to muslims and muslim immigration, and perhaps Myanmar, who let armies massacring and raping muslims run wild for a few years ...
Good luck convincing them not having global warming is a good idea. Once the issue moves toward criticality, Good luck convincing them not to start a war ... WITH global warming, it's ~70 years before the issue becomes critical, without, perhaps 15.
We need to take active control of the climate. It's not a choice, it's a necessity. One thing I find funny is that when you look at the issue globally, I think the best solution is, well definitely not cooling (and just as warming is totally unavoidable now, a cooling cycle will start perhaps as early as 2200. That will rapidly become a lot worse than global warming is now). Perhaps something like 0.5 degrees per century from this point forward. What we actually want is to slow and extend global warming for at least a few hundred more years.
The ipcc reports cover solar-radiation-modification/management and geoengineering generally along with mitigation and adaptation.
Currently they say if we don't move to renewables, carbon fees etc. faster then we'll need to do some of this. But it would be cheaper to avoid it as much as we can:
> Uncertainties surrounding solar radiation modification (SRM) measures constrain their potential deployment. These uncertainties include: technological immaturity; limited physical understanding about their effectiveness to limit global warming; and a weak capacity to govern, legitimize, and scale such measures. Some recent model-based analysis suggests SRM would be effective but that it is too early to evaluate its feasibility. Even in the uncertain case that the most adverse side-effects of SRM can be avoided, public resistance, ethical concerns and potential impacts on sustainable development could render SRM economically, socially and institutionally undesirable (low agreement, medium evidence)
Switch to renewables and storage for energy production, switch over everything to electric, making it more efficient. Then let the natural systems deal with the remaining excess carbon how they deal with volcanic co2.
Sequestering carbon using current methods requires too much energy. In order for CCS to work out we need a surplus of green energy, and we have a deficit.
Geo-engineering could be done by changing the planet’s albedo, for example by seeding the upper atmosphere with certain chemicals, but on the one hand we don’t understand the earth’s climate system well enough to do this safely, and on the other hand it’s like having a foot on the gas and a foot on the brake at the same time, intuitively you can tell this isn’t a good solution.
Since the current answers only consider albedo-tuning and mechanical CCS: Ocean fertilization[0] may be another solution to carbon capture.
The idea is that iron is the main limiting factor to algae growth, so that adding iron to currently barren areas in the oceans would allow algae growth on a very large scale.
No, not made up extremism. It is a risk which becomes more likely.
Just for kicks, what happens if the existing, current drought in the US (worst in 1200 years) continues and/or worsens over the next two years, cutting agricultural production and raising the cost of food (disclaimer: long CORN).
https://droughtmonitor.unl.edu/
Ok, since we are explicitly discussing floods, and you explicity say "cycle that has happened before",
Define flooding as California megaflood puts LA/Orange county underwater.
TL/DR, risk is now 2x historic and is expected to rise to 4-7x historic.
Historical: floods equal to or greater in magnitude to those in 1862 occur five to seven times per millennium [i.e., a 1.0 to 0.5% annual likelihood or 100- to 200-year recurrence interval (RI)]
...
We find that climate change to date (as of 2022) has already increased the annual likelihood of an ARkHist event by ~105% relative to 1920 in the CESM1-LENS ensemble and of an even higher magnitude (200-year RI) event by ~234%. This finding is consistent with prior work reporting progressively larger increases in projected extreme precipitation events for increasing event magnitudes [e.g., (42)]. We further find that by ~2060, on a high emissions trajectory, the annual likelihood of an ARkHist level event increases by ~374% and by ~683% for a formerly 200-year RI event.
Any science behind your implied claim that port cities will stop operating because of sea level rise, rather than adapting or migrating?
It's incredible how widespread misinformation about climate change is. All these replies from people who support the OP's claim but have no idea why and are just taking random stabs at imagined reasons.
We’re still just hoping we stop polluting. It’s not happening fast enough.
Edit: Do we actually have any chance of using geoengineering to turn things around?