The 1815 eruption of Mount Tambora induced a climate crisis and changed world history

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The Year Without a Summer was only 32 years after the colossal eruption of Laki in Eastern Iceland.

Laki had a catastrophic effect on the Northern Hemisphere - the near evacuation of Iceland, 23,000 dead in England (equivalent to about 300,000 today); crop failures across Western Europe; the coldest winter on record (until Tambora); the Mississippi freezing in New Orleans and ice floes in the Gulf of Mexico; a failure of the Nile flood that may have killed 20% of the Egyptian population; the collapse of the Indian monsoon which led to famine in India and Northern China. Subsequent years saw the climate oscillate crazily which had a particularly severe effect on agriculture in France, eventually culminating in the French Revolution.


Remember also that the blood red sunsets caused by these volcanic eruptions were also the inspiration for Edvard Munch’s famous painting “The Scream”. In that case it was most likely the sunsets caused by the eruption of Krakatoa about a decade before he painted it that inspired him.

It’s hard now not to look at that painting and see in it the psychological reaction you get when you finally realise how serious modern climate change is for humanity.


This example of natural geoengineering is one of the only things that gives me hope for the planet staying hospitable to our civilization. What’s surprising is how narrow the band of support for such action by humans is. The right is obviously against it, and the left feels we should be able to reverse climate change by will power alone. Recently I argued this subject with an old friend who’s an accomplished exogeologist, and was surprised at his negativity and support of what seems economically unrealistic carbon removal and sequestration ideas. Maybe I’ve read too much SF but I’d rather have hope than ideological purity.


It’s a radical solution, if it works at all. Can you really be sure that we’ll get the desired effects and not accidentally plummet the planet into an extended nuclear winter scenario? I’m not dismissing it but it seems to me an option of last resort.


Ditto a lot of Turner’s paintings, which all seem to have a red pall of volcanic dust and haze over them:


We’re not talking about nuking a volcano! Most of the proposals I’ve read are pretty mild and require repeated renewal, so if there’s serious adverse effects all you do is stop what you’re doing. The biggest criticism I’ve heard is it will make people think it’s OK to keep burning carbon, rather than it being 1st aid to the climate while we ramp down the carbon economy. That’s like someone thinking the tourniquet on their leg means they don’t need to go to the hospital.


I think I’ve linked to this book before, but among the five extinction events described here, only one is at least partially supposed to have been from an impact, the rest are theorized as being caused by climates becoming unbalanced due to runaway volcanism among other organic and geological effects. Ugh:

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My bad I was looking for a suitable metaphor, using actual nukes would be moronic :grin:

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Then you need to read more about them. The climate modelling experiments reveal that none of the proposals really work. Take for example spreading sulphate aerosols in the stratosphere to reflect incoming sunlight. If you look at global mean temperatures, it looks like they do an an amazing job, and the amounts can be tweaked to give a very fine grained control over the planet’s mean temperature. But the problem is that mean temperature hides a huge amount of regional variation. Some parts of the planet still warm a lot, other parts cool too much, and rainfall patterns are disrupted everywhere. So while the average effect may look fine, nearly every nation will be unhappy with the impacts. Now imagine the international negotiations needed to decide what to do about it - we can’t even agree on emissions reduction targets for CO2, let alone how to manage a geoengineering project that may have devastating effects in many parts of the world.

Oh, and if you decide to stop once you’ve started, you get all the warming you masked, delivered in one go. That’ll be far worse than a steady warming over decades. Basically, once you’ve started on these geoengineering projects you cannot stop, no matter how bad the impacts.

Here’s how I think about geoengineering. We’re already conducting a massive geoengineering project on the planet. Its completely out of control, and we cannot agree even that it needs fixing, let alone agree on a set of necessary measures needed to fix it. Do we really want to start another geoengineering project in response to the impacts of the first one?

Or more simply: you cannot solve a problem using the same approach that caused it in the first place.


You mean using that mechanical device called a ‘brake’ will not solve the problem that the device called an ‘engine’ caused of sending you speeding at a brick wall? You say effects will be uneven globally? You mean just like the effects of warming are now?

I wish there were great alternatives to this kind of action, but we haven’t even slowed the increase in rate of carbon emissions, never mind reduced the actual carbon in the atmosphere that will continue to warm the planet for generation. Saying a solution isn’t perfect is like the doctor saying the treatment required to save the patient might have side effects. At some point there is little practical choice, and like many diseases, the longer you wait the harder the cure will be. I am certainly not saying we shouldn’t do everything possible to eliminate carbon emissions, I just fear it’s too late.

Also, I don’t think you’re correct in saying “if you decide to stop once you’ve started, you get all the warming you masked, delivered in one go.” The warming had been suspended, it will resume, but there is no “collected reservoir” of heat that would be released any more than when you raise the windowshade you suddenly get all the heat from the sun that hadn’t come into the room. The raised albedo of the earth will have reflected the heat to space.

My scientist friend talked about using power generated by massive solar arrays for atmospheric carbon capture. No nation will devote tremendous resources to something like that until you can see the sand in the mortar of the brick wall we’re speeding at. That’s just reality. The wealthiest nation on earth won’t stop burning fossil fuels, how can we expect India to?

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No, but the net radiative forcing will immediately return to the level it would have been without the geoengineering. That implies a large instant step change in net radiative forcing, compared to an incremental increase that would have occurred without the geoengineering. The planet has never experienced an instantaneous step change in radiative forcing on the scale we’re talking about. Here’s a sample trajectory used in the geoengineering model intercomparison projects. This scenario has a steadily increasing SO2 injection designed to exactly match the change in radiative forcing from greenhouse gases, to give net zero change, until the year 2070, when the experiment is stopped. Net radiative forcing immediately jumps, and the model result show extremely rapid warming from 2070 in response to this, at a rate and scale likely overwhelm all adaptation strategies.

Starting down this road and then cancelling the project will be far worse for human civilization than not doing it at all. Oh, and SO2 washes out as acid rain within a few weeks. So forest growth will be hampered throughout the experiment, meaning less CO2 sequestration.


This is where I have a hard time with your position. Does it not account for buying time to really reverse CO2 buildup or perhaps developing better heat averting technology so that jump is not there when you stop? I vote for kicking the can down the road treating the symptom while we do everything we can to treat the cause. As is, processes like permafrost melting will add hard to reverse positive feedback to the warming process, and billions of people who live in low lying shores are going to be refugees.

You are against geoengineering. What are you for that isn’t wishful, magical thinking, like the developed world cut their standard of living and the developing nations stop aspiring? I’m doing my part, live in a small space in an attached rowhouse and don’t drive to work. But my home is at about 9’ above sea level and escaped Sandy by a couple of blocks.

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Yeah, we’d been to build like a giant robot or something sensible like that.

Maybe, you know, intentional sequestration of carbon in a stable form from multiple biomass sources that are normally waste products? Biochar can be buried and recovered if needed. So4 in the atmosphere wreaks havoc on various forms of life, which is the primary reason we started regulating coal emissions, long before CO2 was a major concern.

I mean, geoengineering is an option, along with reduction of carbon emissions, and mitigation of hazards with things like dikes. It is just a crappy option.

I’m absolutely against trying to use SO2 injection against climate change, but this is not one of the reasons. In fact, in the atmospheric level where it is supposed to be injected is relatively stable, and all models predict it would stay there for years. Also, it’s far above the zone where rain even begins to form.

Trying to mimic the effect of a volcanic eruption - such as by sulfur aerosols may slow warming - but they won’t stop the other effects, such as acidification of the oceans which are going to be catastrophic and potential acidified precipitation harming forests and agriculture alike. Slowing cooling might give politicians a fig leaf to say they did something about global warming, but that would just allow us to keep pouring CO2 into the atmosphere and destroying the environment.

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I’ve heard people use this argument so many times, and I find it a false assumption. It’s like saying why change the baby’s diaper since she’s just going to crap it again. You change the diaper till you can toilet train her. I agree geoengineering without doing everything possible to reduce carbon emissions and eventually sequester carbon is stupid. I’ve not heard ANYONE propose that. Nor have I heard a practical alternative suggested by all the naysayers.

We need to stop the warming NOW! Just like stopping the bleeding of an accident victim without arguing about whether they need to be in rehab or they’ll crash the car again. Fail to stop the bleeding and rehab won’t be an option.

The fossil fuel industry hasn’t used this talking point yet? I find that hard to believe.

Even they aren’t stupid enough to suggest geoengineering is the way to keep happy motoring along.