Controlling a volcanic eruption to stall climate change?

[Airbrush]

Maybe this is better in Climate Science?  But engineering is what people DO to address human problems. 

About all humans can do to control anything about a volcano is to divert lava flows.  But what if we could get a volcano to erupt on demand?  Or kept erupting to deliver enough dust to the atmosphere to cool the earth enough to stall global warming?  The big island of Hawaii has a volcano called Mona Loa erupting.  Could it be used to deliver dust to the atmosphere, if the winds are blowing east the dust would get into the atmosphere before falling on the western US.  Is there anything we could throw into the volcano that would help?

"Climate scientists bring up volcanic eruptions to better understand and explain short periods of cooling in our planet’s past. Every few decades or so, there is a volcanic eruption (e.g., Mount Pinatubo, El Chichón) that throws out a tremendous amount of dust and gases. These will effectively shield us enough from the Sun to lead to a short-lived global cooling period. The particles and gases typically dissipate after about 1 to 2 years, but the effect is nearly global."

What do volcanoes have to do with climate change? – Climate Change: Vital Signs of the Planet (nasa.gov) 

Edited January 14, 2023 by Airbrush

[exchemist]

1 hour ago, Airbrush said:

Maybe this is better in Climate Science?  But engineering is what people DO to address human problems. 

About all humans can do to control anything about a volcano is to divert lava flows.  But what if we could get a volcano to erupt on demand?  Or kept erupting to deliver enough dust to the atmosphere to cool the earth enough to stall global warming?  The big island of Hawaii has a volcano called Mona Loa erupting.  Could it be used to deliver dust to the atmosphere, if the winds are blowing east the dust would get into the atmosphere before falling on the western US.  Is there anything we could throw into the volcano that would help?

"Climate scientists bring up volcanic eruptions to better understand and explain short periods of cooling in our planet’s past. Every few decades or so, there is a volcanic eruption (e.g., Mount Pinatubo, El Chichón) that throws out a tremendous amount of dust and gases. These will effectively shield us enough from the Sun to lead to a short-lived global cooling period. The particles and gases typically dissipate after about 1 to 2 years, but the effect is nearly global."

What do volcanoes have to do with climate change? – Climate Change: Vital Signs of the Planet (nasa.gov) 

What if the sky was made of concrete? Forget it.

We can't hope to control volcanic eruptions. 

 

[TheVat]

And if we could trigger them, there's the problem that eruption is often pretty unpleasant for those who live nearby.   (also, lots of dust can backfire if it deposits heavily on glaciers or snowfields, lowering the albedo for an extended period)

I'm surprised they don't erupt more, given that we have stopped sacrificing virgins to appease the volcano gods.  

[Genady]

4 minutes ago, TheVat said:

eruption is often pretty unpleasant for those who live nearby

That's why we take care that it's not us:

4 hours ago, Airbrush said:

if the winds are blowing east the dust would get into the atmosphere before falling on the western US

 

[swansont]

I’m guessing people with respiratory issues would love this. Like Seattle residents during the forest fires this past summer.

 

6 minutes ago, TheVat said:

I'm surprised they don't erupt more, given that we have stopped sacrificing virgins to appease the volcano gods.  

What do mean “we”?

I personally sacrificed twice as many last year as compared to a decade ago.

[MigL]

Triggering volcanoes to combat global warming ...
That's like cutting off an arm in an effort to lose weight.

[exchemist]

Interestingly, a lot of articles on the effects of eruptions on climate mention sulphate aerosols in the stratosphere exerting a cooling effect. One or two tantalisingly refer to IR absorption by these particles. But I have trouble understanding this, as absorption of IR by CO2 (and water) is exactly what gives rise to the greenhouse effect. So how can what seems to be the same thing cause cooling?

If it were a process of reflection, i.e. increasing the albedo of the upper atmosphere to reduce the sunlight incident on the surface of the Earth, that would be something I could understand. But in that case, why would sulphate aerosols be particularly effective? Surely any old dust grains might do the job?   

Does anyone know? 

 

[iNow]

5 hours ago, exchemist said:

So how can what seems to be the same thing cause cooling?

shade

[exchemist]

15 minutes ago, iNow said:

shade

I can't see how that can explain it because, as far as IR is concerned, CO2 and water would "shade" in the same way.

The point about the greenhouse effect, as I understand it, is that incoming radiation of all wavelengths is converted to IR by the Earth's surface, re-radiated from it as IR - and is then absorbed and scattered by CO2 and water, ricocheting around the atmosphere instead of being emitted into space, and thus heating up the atmosphere. 

Shade as a mechanism can work if fine particles (whether sulphate or other) reflect radiation of all wavelengths (my previous comment about albedo - but in that case why would sulphate be specially effective?) or, I suppose, if they reflect just IR, but if they absorb IR they will heat up the atmosphere, won't they? 

 

[iNow]

CO2 isn’t the only thing ejected by erupting volcanoes. Ash and dust matter here, too. 
 

https://scied.ucar.edu/learning-zone/how-climate-works/how-volcanoes-influence-climate

Quote

Small ash particles form a dark cloud in the troposphere that shades and cools the area directly below. Most of these particles fall out of the atmosphere within rain a few hours or days after an eruption. But the smallest particles of dust get into the stratosphere and are able to travel vast distances, often worldwide. These tiny particles are so light that they can stay in the stratosphere for months, blocking sunlight and causing cooling over large areas of the Earth.

 

Edited January 16, 2023 by iNow

[swansont]

2 hours ago, exchemist said:

can't see how that can explain it because, as far as IR is concerned, CO2 and water would "shade" in the same way.

Shade of visible radiation. And the IR behavior wouldn’t necessarily be the same. The solar IR spectrum is weighted toward near-IR (1-2 microns), while the earth emissions are mid-IR (out near 10 microns) so strong absorption near 1-2 microns would shield us from solar but not trap earth emission.

[TheVat]

3 hours ago, exchemist said:

I can't see how that can explain it because, as far as IR is concerned, CO2 and water would "shade" in the same way.

The point about the greenhouse effect, as I understand it, is that incoming radiation of all wavelengths is converted to IR by the Earth's surface, re-radiated from it as IR - and is then absorbed and scattered by CO2 and water, ricocheting around the atmosphere instead of being emitted into space, and thus heating up the atmosphere. 

Shade as a mechanism can work if fine particles (whether sulphate or other) reflect radiation of all wavelengths (my previous comment about albedo - but in that case why would sulphate be specially effective?) or, I suppose, if they reflect just IR, but if they absorb IR they will heat up the atmosphere, won't they? 

 

Sulphates form compounds at altitude that are especially good at reflecting solar radiation (you'd have to look it up, but there's some sort of scattering index that indicates the relative degrees of scattering and absorption - I'm a little rusty on this).  Also, they make good condensation nuclei.  You will recall that diffuse water vapor is a GHG (and CO2 effect magnifier), but condensed droplets (i.e. clouds) increase albedo and reflect radiation.  

That's why there's an anomalous cooling trend (or rather, flattening of the global warming trend IIRC) during the decades 1940-1970s, due to a massive escalation in burning of high-sulfur varieties of coal.  As soon as this was curtailed, as governments started dealing with the acid rain problem, that cooling effect went away.  

[exchemist]

1 hour ago, swansont said:

Shade of visible radiation. And the IR behavior wouldn’t necessarily be the same. The solar IR spectrum is weighted toward near-IR (1-2 microns), while the earth emissions are mid-IR (out near 10 microns) so strong absorption near 1-2 microns would shield us from solar but not trap earth emission.

Plausible. Do you know this is is why sulphate is considered a net anti-greenhouse emission, or is this just reasonable speculation? 

7 minutes ago, TheVat said:

Sulphates form compounds at altitude that are especially good at reflecting solar radiation (you'd have to look it up, but there's some sort of scattering index that indicates the relative degrees of scattering and absorption - I'm a little rusty on this).  Also, they make good condensation nuclei.  You will recall that diffuse water vapor is a GHG (and CO2 effect magnifier), but condensed droplets (i.e. clouds) increase albedo and reflect radiation.  

That's why there's an anomalous cooling trend (or rather, flattening of the global warming trend IIRC) during the decades 1940-1970s, due to a massive escalation in burning of high-sulfur varieties of coal.  As soon as this was curtailed, as governments started dealing with the acid rain problem, that cooling effect went away.  

That sounds like it could be it.

So we have three potential mechanisms:

- selective IR absorption to block short IR from reaching the ground

- efficient reflection/scattering by sulphate 

- nucleation for formation of high altitude clouds

I'll have to try to read something on these to see what I can find.  

 

[swansont]

1 hour ago, exchemist said:

Plausible. Do you know this is is why sulphate is considered a net anti-greenhouse emission, or is this just reasonable speculation? 

Just a general observation that saying that something absorbs in the IR isn’t specific enough to know how it ties in to the greenhouse effect

The condensation from particulates that TheVat mentions is what I recall as being an important effect. (I recall a colloquium where it was shown you could track ships from satellites from the condensation caused by their smokestack emissions on an otherwise cloudless area of the ocean)

[Ken Fabian]

12 hours ago, exchemist said:

Does anyone know?

 

3 hours ago, exchemist said:

- selective IR absorption to block short IR from reaching the ground

If it were absorption within the atmosphere that energy would be added to the atmosphere. It isn't absorption.

 

3 hours ago, exchemist said:

- efficient reflection/scattering by sulphate

This appears to be the correct option. As I understand it gaseous Sulphur Dioxide is the precursor to droplets of sulphuric acid that are reflective to sunlight. Being initially gaseous probably makes it easier to get pushed high in the atmosphere by volcanoes and for the resulting droplets to linger there, up to 2 years and global in effect. Human sources ie from fossil fuel burning rarely make it that high and have residence times of a few days and is more regional in effect.

 

3 hours ago, exchemist said:

- nucleation for formation of high altitude clouds

 From NASA -

Quote

The sulfate aerosols also enter clouds where they cause the number of cloud droplets to increase but make the droplet sizes smaller. The net effect is to make the clouds reflect more sunlight than they would without the presence of the sulfate aerosols.

This source doesn't specify the altitude of the clouds, but sounds like it has a reflective cooling effect.

 

Regarding the initial question(s) -

On 1/15/2023 at 6:11 AM, Airbrush said:

But what if we could get a volcano to erupt on demand?  Or kept erupting to deliver enough dust to the atmosphere to cool the earth enough to stall global warming? 

First, we don't know how to get volcanoes to erupt on demand or continuously. There are proposals for deliberately adding sulphate aerosols to the stratosphere but with (usually) aircraft, not via volcanoes.

Sulphate aerosols aren't dust. Not sure dust is such a highly significant factor - probably doesn't linger long enough. But, to echo MigL, massively increasing volcanic activity seems counterproductive.

The cooling effect of aerosols depends on the rate you keep adding, whereas global warming is dependent on the accumulated total of CO2 (over the timescales that matter). It doesn't fix the cause, just masks the effects - and the consequences are more complex than simply reducing global warming, ie may induce significant unwanted regional climate changes.

My view is that - given existing climate politics - anything gives the illusion that we can keep burning fossil fuels at high rates and avoid the climate consequences is unhelpful -  even where those attempts are sincere. Whether intended as an adjunct to commitments to building an abundance of clean energy and reducing emissions it will be used by opponents - and the apathetic - to reduce those ambitions.

[CharonY]

Rather than using vulcanoes, there have been discussions about using sulphate aerosols directly (folks called it geoengineering). The big issue with these large-scale approaches are the uncertainties regarding the effects on various scales (local to global). A somewhat older review is here, but there will be newer material out there (https://doi.org/10.1098/rsta.2008.0131).

[exchemist]

9 minutes ago, Ken Fabian said:

 

If it were absorption within the atmosphere that energy would be added to the atmosphere. It isn't absorption.

 

This appears to be the correct option. As I understand it gaseous Sulphur Dioxide is the precursor to droplets of sulphuric acid that are reflective to sunlight. Being initially gaseous probably makes it easier to get pushed high in the atmosphere by volcanoes and for the resulting droplets to linger there, up to 2 years and global in effect. Human sources ie from fossil fuel burning rarely make it that high and have residence times of a few days and is more regional in effect.

 

 From NASA -

This source doesn't specify the altitude of the clouds, but sounds like it has a reflective cooling effect.

 

Regarding the initial question(s) -

First, we don't know how to get volcanoes to erupt on demand or continuously. There are proposals for deliberately adding sulphate aerosols to the stratosphere but with (usually) aircraft, not via volcanoes.

Sulphate aerosols aren't dust. Not sure dust is such a highly significant factor - probably doesn't linger long enough. But, to echo MigL, massively increasing volcanic activity seems counterproductive.

The cooling effect of aerosols depends on the rate you keep adding, whereas global warming is dependent on the accumulated total of CO2 (over the timescales that matter). It doesn't fix the cause, just masks the effects - and the consequences are more complex than simply reducing global warming, ie may induce significant unwanted regional climate changes.

My view is that - given existing climate politics - anything gives the illusion that we can keep burning fossil fuels at high rates and avoid the climate consequences is unhelpful -  even where those attempts are sincere. Whether intended as an adjunct to commitments to building an abundance of clean energy and reducing emissions it will be used by opponents - and the apathetic - to reduce those ambitions.

This is all good stuff. 

The only unresolved issue now is the bit I read somewhere about absorption of IR by sulphate. I'll have to find that again and re-read.  

[Ken Fabian]

On 1/17/2023 at 9:23 AM, exchemist said:

The only unresolved issue now is the bit I read somewhere about absorption of IR by sulphate. I'll have to find that again and re-read.  

I don't see how any solar IR absorption in the atmosphere could result in anything other than adding some energy into the atmosphere, ie add to warming. Affected incoming solar IR at the top of atmosphere should result in about 1/2 re-radiated back to space, from being absorbed from one direction and re-radiated equally in all directions, approximately half going up, half going down, with a net gain in energy in the atmosphere. IR from ground level mostly doesn't make it to space in one go.

It has been a common misconception that CO2 should block incoming solar IR, as it blocks outgoing but that isn't the case; any energy absorbed within the atmosphere becomes energy inside the climate system. To "block" incoming IR takes reflection, not absorption.

Edited January 17, 2023 by Ken Fabian

[exchemist]

7 hours ago, Ken Fabian said:

I don't see how any solar IR absorption in the atmosphere could result in anything other than adding some energy into the atmosphere, ie add to warming. Affected incoming solar IR at the top of atmosphere should result in about 1/2 re-radiated back to space, from being absorbed from one direction and re-radiated equally in all directions, approximately half going up, half going down, with a net gain in energy in the atmosphere. IR from ground level mostly doesn't make it to space in one go.

It has been a common misconception that CO2 should block incoming solar IR, as it blocks outgoing but that isn't the case; any energy absorbed within the atmosphere becomes energy inside the climate system. To "block" incoming IR takes reflection, not absorption.

Exactly my thoughts on that, hence the question I raised initially. Though I take @swansont‘s point about different regions of  the IR spectrum.

[Airbrush]

On 1/16/2023 at 2:12 PM, Ken Fabian said:

 

My view is that - given existing climate politics - anything gives the illusion that we can keep burning fossil fuels at high rates and avoid the climate consequences is unhelpful -  even where those attempts are sincere. Whether intended as an adjunct to commitments to building an abundance of clean energy and reducing emissions it will be used by opponents - and the apathetic - to reduce those ambitions.

Excellent info, thanks for that.  What do you think of billions of ping pong balls to cover the arctic ocean to reflect sunlight? 

I thought of volcanoes in Antarctica or Alaska, or wherever the wind direction is away from populated areas.  But it would be terribly dirty no matter where the volcano is located.  Also, they would need to excavate the volcano with nukes.

Or foresting deserts?  If you could desalinate sea water, sun-powered water distillation, while you plant the desert with trees, one tree at a time, one water-hose per tree to not waste water.  The forest starts small and expands outward.

Or is there a device that can be built to large-scale to extract CO2 from the air, that works faster than a tree can?

Think of anything that can bridge the 50-year gap between today and an idyllic future that is totally carbonless and clean, abundant energy for cheap.

Edited January 19, 2023 by Airbrush

[swansont]

42 minutes ago, Airbrush said:

Or is there a device that can be built to large-scale to extract CO2 from the air, that works faster than a tree can?

Yes, but with limited deployment, and under further developmant

https://www.iea.org/reports/direct-air-capture

https://en.m.wikipedia.org/wiki/Direct_air_capture

[TheVat]

The problem, well documented now, of tree planting programs is that they are often greenwashing - species are planted without consideration of their hardiness and water/soil requirements in relation to the bioregion.  There's a brief period of being attentive, then most of the saplings die off.  A better approach is restoring ecosystems, sometimes called rewilding...

https://www.newyorker.com/magazine/2022/12/19/the-promise-and-the-politics-of-rewilding-india

 

 

1 hour ago, Airbrush said:

What do you think of billions of ping pong balls to cover the arctic ocean to reflect sunlight? 

What do you think of massive increases in microplastic pollution, as the balls erode over time?  Microplastic pollution is already a major global problem, and threat to oceanic food chains (including phytoplankton).

[Ken Fabian]

These kinds of options appear to offer ways to reduce the harms from the enhanced greenhouse effect but they don't address the emissions and the enhanced greenhouse effect that are the source of the problem, which are cumulative and get progressively more serious the longer emissions are not addressed. They also tend to not actually exist as actual, viable options. It is always worthwhile to explore all options, including the big geoengineering ones, but not as alternatives to addressing the emissions themselves using the capabilities that we have now and/or are within our grasp.

Building clean energy that displaces fossil fuel use isn't hypothetical and at this moment in time isn't even a more expensive option. As I see it we should allow nothing to divert the primary focus of our efforts away from shifting our primary energy supply to non-emitting alternatives.

In large part the current global growth of wind and solar, around and above 20% pa - I haven't checked but expect that solar alone is being added to the world's inventory faster than fossil fuel power plants were ever added. Largely the current growth is due to becoming cost competitive with fossil fuels without emissions considerations, but I believe a true zero emissions goal requires more foresight and commitment with greater growth of low emissions/no emissions alternatives than leaving it up to "free" markets that continue to give unfair advantage to fossil fuels, including by the enduring amnesty on climate accountability they enjoy. I don't think "free" ever truly meant free from accountability, nor that requiring it is anti-capitalist.

The current market advantage of RE is far from absolute or happening everywhere and there are potential resource constraints and other bottlenecks - although I expect the worst of them will come from nationalistic geo-political gamesmanship, more akin to the denying supply that features with fossil fuels than any genuine resource shortages.

It is still remarkable how well RE/EV's/batteries are doing, especially given that fossil fuels have powerful advantage from pre-existing incumbency - they are what energy companies and banks and energy planners know best and what cashed up fossil fuel companies lobby for relentlessly. And there is that enduring amnesty on any accountability for externalised climate harms, ie they continue to (mostly successfully) avoid accountability and they socialise those emerging costs to sustain exceptional corporate profitability, usually with systematic and successful tax avoidance thrown in. And if anyone can mass manufacture low cost, ultra safe, reliable, low cost modular nuclear that are low cost (did I mention low cost?) and conservative-right politics support for climate action comes out from behind their fossil fuel defending Wall of Denial we may see nuclear options become more widely used as well. But I don't expect much actual stratospheric aerosol injection, or Direct Air Capture or other CCS that isn't tied to efforts to extend the use of fossil fuels.

[Airbrush]

CO2 Direct Air Capture (DAC)

"Plans for a total of eleven DAC facilities are now in advanced development. If all of these planned projects were to go ahead, DAC deployment would reach around 5.5 Mt CO₂ by 2030; this is more than 700 times today’s capture rate, but less than 10% of the level of deployment needed to get on track with the Net Zero Scenario."

Direct Air Capture – Analysis - IEA

That means that after humans switch over to totally carbon-free energy, in about 50 years, by using Direct Air Capture, which requires lots of energy, but it can be increased in scale over time, we can restore a healthy atmosphere.  We could return CO2 in the atmosphere to low, pre-industrial levels.  This would cool the oceans, restore glaciers, moderate weather, re-freeze melting permafrost, and freeze over more of the Arctic Ocean.  It won't hurt to also plant groves of trees and dedicate a dependable water supply to each tree, so that no tree's water supply gets interrupted.

Edited January 23, 2023 by Airbrush