How do you feel about addressing global warming with geo-engineering?

Question

"In a worrying sign that scientists may be slowly succumbing to the siren song of geo-engineering, a panel of top climate researchers cautiously endorsed a proposal to fund more research looking into unorthodox ways to stop global warming. While no formal statement was released, Phil Rasch, a modeler with Boulder's University Corporation for Atmospheric Research and a member of the panel, spoke for the great majority of his colleagues when he stated: "We're not saying that there should be geoengineering, we're saying there should be research regarding geoengineering."

http://www.treehugger.com/files/2007/11/scientists_consider_geoengineering.php

The problem with geoengineering (examples given in the link above) is that it's risky to mess with nature. What are your thoughts on this potential option in addressing global warming?

Answer 1

It's not something I relish but, all things considered, we may be left with no alternative. I'll explain why in this rather long answer.

There's perhaps 20 or 30 different geo-engineering schemes that have been mentioned, they come with varying degrees of conviction behind them.

Perhaps the most extreme of all suggestions, and this really was considered, is to move the planet into a different orbit. It's been calculated that by moving the planet into an orbit with a mean distance from the Sun of 94.5 million miles the reduction in incoming solar radiation would negate the effects caused by the increased greenhouse effect. One tiny flaw with the scheme being that it would require the force of something like 40 million nuclear weapons and there is the distinct possibility that life on Earth would be wiped out.

Even if such a madcap scheme were pulled off, we would then have to deliberately pollute the atmosphere in order to compensate for the reduced heat received from the Sun.

There are other less drastic schemes that have been proposed. One such scheme advocated by Prof. Paul Crutzen is to inject sulphur dioxide into the upper atmosphere and so mimic the cooling effect that is a consequence of major volcanic eruptions.

The plan being to launch sulphur laden rockets, the sulphur would then be burned at altitudes upwards of 30km from Earth's surface and so envelop the planet in a thin layer of reflective sulphur dioxide gas, enough to reflect some of the solar radiation back into space before it reaches the Earth's surface. Unfortunately sulphur dioxide was the primary contributor to acid rain and it's many other associated problems. So again, perhaps not the best idea ever conceived.

A couple of other schemes that adopt the approach of blocking sunlight involve the use of gigantic solar mirrors up to 100km in diameter, these mirrors would be in orbit around the planet and reflect sunlight back into space.

Another idea proposes the launching of four trillion microscopically thin glass lenses, these would be controlled by solar powered microprocessors and their purpose would be to refract light passing through them ever so slightly, just enough so that it missed Earth.

The last two schemes do at least have some degree of controllability about them but they come at a cost - $452 trillion in the case of the 'global sunshade' (based on using the Space Shuttle to transport the discs into orbit, the costs could be reduced to just a few tens of trillions of dollars by developing electromagnetic terrestrial propulsion methods).

One scheme, that does to my mind at least, have a greater degree of acceptability about it, involves the artificial production of clouds. Certain clouds are more reflective than others and the best ones for reflecting sunlight back into space are marine stratocumuli. As the name suggests, these are high altitude clouds that form over the seas and oceans.

The scheme, devised by Professors Salter and Latham, involves a fleet of automated vessels, self-propelled by wind driven Flettner rotors, sailing the worlds oceans. They would spray a high velocity jet of sea-water high into the air, the salt crystals would form the nuclei around which water vapour would condense to form the clouds.

Unlike some of the other schemes, this one can at least be controlled and has the ability to be scaled up or down on demand. The most noticeable effect of this method, besides global cooling, would be an increase in the amount of rain falling over the oceans.

There are some proposals which are looking at mimicking nature. The forerunner in this area is the use of phytoplankton. These minute marine plants exist in vast numbers in some parts of the oceans, they're invisible to the naked eye but can be seen from space as blue-green blooms in the oceans. They need nutrient rich water in which to survive and reproduce, the thinking is that by enriching parts of the oceans that are currently devoid of certain nutrients, their growth can be encouraged.

Trials have already been conducted which involved seeding a section of ocean with iron filings, these trails met with some success. A similar proposal advocates the use or urea to enrich areas of ocean lacking in nitrogen.

Because phytoplankton are plants they photosynthesise and in doing so they remove carbon dioxide from the atmosphere. When the plants die they sink to the ocean floor taking the sequestered carbon with them.

The use of algae has also been trialed as this follows the same principle.

There are several other schemes, I won't go into detail but they're adaptations of the principle of reducing sunlight or removing carbon dioxide from the atmosphere.

One scheme I haven't mentioned, and this would be my preferred option if we were forced down the geo-engineering route, is one that has been colloquially termed the artificial or synthetic tree.

It's so called because it copies a real tree by removing CO2 from the atmosphere and vaguely resembles a tree in appearance. The device consists of a large open-slatted 'screen', exposed to the atmosphere and mounted atop a column.

Sodium hydroxide within the 'screen' would sequester CO2 from the atmosphere. There are a couple of ways of doing this and both involve a bit of chemistry. One involves the use of atomised sodium hydroxide to react with the CO2 and produce sodium bicarbonate. Calcium oxide would be added and the NaOH recovered for reuse, the residual calcium carbonate would be heated and the CaO recovered for reuse leaving behind CO2 for disposal underground.

A similar scheme using NaOH has been proposed by Prof. Klaus Lackner, it employs a different chemical process (described in the link below) but comes with the advantage that the byproduct is synthetic diesel or gasoline which can be sold to offset the running costs.

The synthetic tree approach has several advantages. Unlike the other proposals it doesn't interfere with any natural mechanism or process, it simply removes what we're adding to the atmosphere. It's fully controllable and can be stopped, started, increased or decreased with ease. It's an efficient system with each 'tree' having the capacity to remove 90,000 tons of CO2 from the atmosphere each year (roughly the equivalent emissions from a town of 15,000 people). By comparison to some other schemes it's relatively cheap, as far as I'm aware there's no accurate costings available but it's likely to be in the order of $10 per person per year.

One big advantage is that it's simply an adaptation of existing technology which has been used successfully for many years around the world. Effectively it's taking the emission scrubbers away from factories and smoke-stacks and placing them in the open atmosphere.

Of course, geo-engineering schemes, as good or bad as they may be, don't address the underlying cause of global warming - they're basically treating the symptoms without treating the cause.

The problem in treating the cause - greenhouse gases - is that it requires radical solutions. Some greenhouse gases are more effective at contributing to global warming than others, as an across the board figure we would need to reduce our emissions to approx 7.5% of their current levels. This isn't remotely practical at present as to achieve such a massive reduction would mean either stepping back in time by approx 200 years or massive changes in our lifestyles.

It wouldn't be enough simply to dispense completely with fossil fuels (not just oil, coal and gas but all the derivatives as well such as aviation fuel, rubber, plastic etc) we'd also need to radically overhaul agricultural practices and all but stop quarrying, mining, cement production, deforestation and any number of industrial processes. This isn't going to happen for a long, long time.

We have some serious problems to face in the future and some serious questions that need to be asked...

● For all intents and purposes, it's going to be impossible to reduce our greenhouse gases emissions to within natural tolerances. Consequently we need to accept, for the foreseeable future at least, that we're going to make the problem worse despite our best efforts to the contrary.

● We have another problem in that the excess greenhouse gases we've already introduced to the atmosphere are going to contribute to global warming for a long time yet. Even if we did cut our emissions to zero the world will keep warming for 60 to 80 more years before a point of equilibrium is reached.

● Unfortunately, the natural chain of events isn't going to intervene and help us out. There are natural cycles that cause warming and cooling, being cyclical they're predictable and it's going to be quite some time before nature lends a hand by entering a cooling phase. Basically, we're on our own with this one.

● Nature does lend a hand in other ways, the oceans for example absorb carbon dioxide but we're screwing this up, so much so that natural absorption has decreased by nearly one fifth and it may get worse.

It leaves us in a position where we have to accept that global warming and climate change are going to be with us for quite some time, 60 years at the very least but more than likely it will be anything upwards of 150 years.

Knowing that climate change is inevitable, the question becomes one of - do we accept climate change and adapt to it as best we can, do we take measures to prevent climate change through mitigation including geo-engineering schemes or do we do a combination of both?

Me personally, I don’t think we should rule out climate engineering. We’re on a downward slope at the moment and accelerating. It may prove to be the silver bullet that pulls us back from the brink, it may be the only chance we have.

These white papers contain a lot more (sometimes technical) information about the synthetic trees option http://www.netl.doe.gov/publications/proceedings/01/carbon_seq/7b1.pdf and http://www.centre-cired.fr/perso/haduong/files/Keith.ea-2005-ClimateStrategyWithCO2CaptureFromTheAir.pdf and this BBC website looks at some of the schemes mentioined above http://news.bbc.co.uk/1/hi/programmes/6298507.stm The website accompanies a one hour documentary that was produced by the BBC and can be viewed on Google Video here http://video.google.com/videoplay?docid=286000425078890061

Answer 2

Wow, great answer Trevor. Something with the least possibility for side effects, simple, only tries to undo what we have done. The synthetic tree idea sounds right. As you say, we might not have a choice.

The web of life has been in a state of dynamic equilibrium since the beginning of life on earth. Every corner of the globe is populated by exactly the right number and types of species that keeps things in balance. It’s possible that everything here is related and interdependent; biological processes, weather, geology, solar and astronomical cycles, even the position of our solar system within our galaxy. Since the beginning of the earth all have influenced one another and we now have the exquisitely balanced system that allows for our existence. However you believe this came into being; it is the objective reality to us humans and is the current unalterable state of affairs on this planet. You cannot change the laws of physics. You cannot violate the laws of thermodynamics. No matter how much you or I wish it were not so, how much you believe we can somehow circumvent the limits, how much you believe someone will come and save us before its too late, every bit of objective science in existence today only reinforces the fact that we are bound to and by the environment we live in.

Taking this to the logical extreme, if you change anything at all, anywhere, you potentially disturb the balance and the outcome is not knowable with any certainty. Would you say that this gives humanity license to change things at will? Or would it be more prudent to wait and perhaps for example apply the great law of the Iroquois – “In our every deliberation we must consider the impact on the next seven generations”. With our current state of knowledge our attempts to engineer the planet amount to a giant uncontrolled global experiment.

My gut tells me that every intervention will lead to a greater, even more intractable problem, leading to a downward spiral of cascading environmental collapse.

We should be doing less, not more.

The sooner we get on with the real issues of population control and per-capita environmental impact, the better chance we have of making it through the bottleneck.

Answer 3

We have been geoengineering, that's what got us into this mess.

I'd say, "Proceed with Caution." Since solutions are all about information-gathering and will be implemented through consensus, I don't see anything to worry about at this juncture. But definitely something to keep an eye on.

Edit: Check out the link below, this sounds like a similar effort. It's only 6 pages and food for thought.

Answer 4

I think everything is a live and learn kinda thing. With geo engineering you have the added benefit of knowledge gained that could be useful in the event of natural disaster.

Global warming should be seen as a climate picture - not just a human generated emissions problem. Getting a grip on an individual and government level is important, but it is also important to investigate alternatives that can provide a measure of protection for events that are not within our scope of control, and geo engineering does just that.

Nature (and life) is already risky.

Answer 5

Yea. First we do not have a good understanding on the cause of global warming, so we don't have a good idea how to fix it. By engineering a solution without a through understanding of the cause can only result in unintended problems that we can't yet comprehend.

30 years ago there was an effort to remove particulates, including sulfur from the air, as they caused environmental problems including acid rain.

Now that these issues are gone, or far reduced, more Sun enters the atmosphere to warm the planet and the solution is to add sulfur and particulates into the atmosphere.

While blocking the Sun will reduce the temperatures of the Earth, as the Sun is responsible for all of the Earth's warmth) we will go back to the days of acid rain and increased breathing problems for the citizens of the world including the children.

It's best to wait until we have a more complete idea of how the climate works first so we can know what solution if any is best to apply. Since it hasn't gotten any warmer since 1998, global warming is most likely over and there would be no reason to do anything to the environment.

Answer 6

Is it risky to mess with nature? Sure it is. But we're doing that now.

In the long run, geoengineering will present a lower risk than unmitigated CO2 increase. I predict that some nation somewhere will begin funding such projects by 2020, and by 2100 it will be routine.

Answer 7

A really bad idea, when we have good ways to reduce our impact up front instead. I agree with this:

"If the Earth came with an operating manual, the chapter on climate might begin with a caveat that the system has been adjusted at the factory for optimum comfort, so don't touch the dials."

Mt. Zion - The temperature increase is well within the margin of error. It's basic science that measuring something thousands of times and averaging reduces error. This graph shows both the temperature rise, and the estimated error (the green bars):

http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

Answer 8

We are not so much dealing with AGW as dealing with the possibility that AGW will occur in the future and some forms of geo engineering appear to have no down side.

It seems like a good idea to sequest some CO2 undergroud and as organic matter on the ocean floor. (some have also proposed capturing CO2 at the point of generation at power stations and sequesting it underground).

What would be the harm in reducing CO2 levels so they are closer to pre-industrial levels.

Answer 9

Why address global warming at all? Half a degree? That's not even outside a reasonable margin of error.

Bob: "It's basic science that measuring something thousands of times and averaging reduces error"

Not if you have a systemic problem with your data collection.

Trouble is, Bob, is that we didn't have all that many weather stations a hundred years ago and assumptions, extrapolations and subjective judgments were made to 'construct' temperature data.

Even modern data has been corrected, e.g., the recent NASA Satellite data that was adjusted .3F. Go ahead, put your faith in 100 year old data full of holes.

Answer 10

Once again, those who "know better than anyone else" are ready to begin something that they
A: Do not understand
B: Could not control if they _did_ understand it

If these idiots actually _try_ this hairbrained scheme, they ( and we all) will find out the true meaning of the phrase "It's not nice to mess with Mother Nature".

Answer 11

I think geo-engineering is a good idea, certainly a better idea than just giving up the use of coal and oil before we have viable alternatives. I also think the the treehuggers will oppose it, just like they oppose everything else.