I’ve been looking into geo-engineering for the past few years and I’m surprised that it hasn’t gotten more consideration until now. For those that don’t know what I’m talking about, geo-engineering is manipulating the climate on a global scale using artificial means. It’s been put forward as a solution to global warming and until recently had been viewed as quackery by most, but is now being mooted by some very well respected scientists.
Geo-engineering ideas that combat global warming come in 2 major flavors: Carbon dioxide reduction and sunlight reflection.
Carbon dioxide reduction combats the greenhouse gas buildup by scrubbing CO2 from the atmosphere and storing (sequestering is the fancy word) it. Less CO2, less heat trapped in the atmosphere, the cooler the earth gets. Some ideas of how to accomplish this:
– convert CO2 into a liquid form and pump it into deep ocean zones.
– pump CO2 gas into old oil fields or in large underground resevoirs
– seed the ocean with iron to feed huge plankton blooms. Most of the plankton will die and sink to the bottom where they will form the next layer of sedimentary rock. Some will be eaten and help feed fish stocks.
I have a problem with each of these. The first two are hugely energy intensive, meaning expensive, and the volume of CO2 to be dealt with is staggering, plus the technology isn’t there yet. Also, there is no long-term solution to what to do with it once it’s stored in liquid or gas form. What would happen if an earthquake suddenly released a massive quantity of CO2 into the atmosphere or into groundwater sources? Some of it is bound to escape, how much will that be and what effect will it have? Also, the natural cycle is for plants to process CO2 and release O2 while using the carbon to produce biomass and sugars, what would happen if we took CO2 out of circulation without adding the O2 back into the atmosphere?
The iron seeding is more acceptible to me because we already understand the dynamics of plankton, although I think there’s a serious danger of severe pollution problems associated with this, and how where would we get the iron?
Another major consideration is that carbon dioxide is only one of the greenhouse gases. Methane is a strong greenhouse gas and there’s a lot of it due to ever-increasing demand for livestock. There’s no known way to deal with it.
Any successful effort to artificially reduce greenhouse gasses will require a higher level of technology than we have right now and that is due to cost. We can do it now but the cost is prohibitive. It’s got to be cheap to do or it will price us right out of doing it.
Sunlight reflection cools the earth by preventing sunlight from being converted to heat. When a photon (a particle of sunlight) hits a surface it either gets reflected as a photon, or absorbed and converted into heat. Heat is then emitted into the atmosphere where some it escapes into space and the rest is trapped by the atmosphere. Sunlight reflection methods seek to increase the earth’s albedo, which is the percentage of sunlight reflected back into space instead of being absorbed as heat. Ideas come in space-based, upper atmosphere based, and surface-based flavors:
– orbit a constellation of satellites that will deflect sunlight before it gets to the earth in the first place
– detonate some large space rock in a closer orbit to the sun to block sunlight
When you consider how much one shuttle mission or a heavy-lift Airane costs the idea of a space-based solution sounds a bit rediculous, especially since we don’t have the technology to build and control large space-based reflectors. We will someday and we should definitely do some research but at this point it’s not realistic.
– Manufacture a fleet of automomous reflector vehicles that will soar into the upper atmosphere and reflect light back into space
– Add particulates to jet fuel to encourage the exhaust plumes of transport aircraft to become clouds. There’s good evidence that jet exhaust is already helping global warming and this could be improved upon.
– Shoot cannon shells full of sulphur compounds into the air to create artificial clouds.
The problem of upper-atmosphere solutions is that it takes energy to get whatever it is up there in the first place and to then keep them there. Add to that the hazards of having thousands, maybe millions of autonomous robot air vehicles flying around and you get the feeling you don’t want that in your backyard. I also don’t like the idea of spraying pollution into the low atmosphere either. The jet fuel idea has promise though as we already have large fleets of aircraft flying, the costs would be minimal, and it would be easy to control.
– build a fleet of nuclear-powered ships that will go to the middle of equatorial oceans and create huge steam plumes, essentially artificial clouds, that will reflect sunlight into the atmosphere.
– Manufacture large numbers of artificial icebergs with reflective surfaces and float them in equitorial waters. Sea ice already is responsible for a sizable chunk of the earth’s reflected light.
Surface-based solutions to me are the way to go as a) you don’t have to spend energy (and therefore money) to fight gravity b) the costs are comparitively low, c) they are based on existing technology and are EASY to do, d) there are few hazards created by doing them, and e) they are easy to control.
It’s understandable why people have been shying away from geo-engineering; deliberately messing with the climate is a frightening thought. Consider however that we are already messing with the climate on a massive scale with greenhouse emissions and de-forestation, so building some space or ocean based sunlight reflectors to offset those changes isn’t crazy at all, in fact it is the only short to mid-term solution that is likely to have any effect.
Let’s look at it with cold logic:
– With the absolute best intentions any efforts to decrease greenhouse gas emissions will take decades and are going to require a massive shift in the way we source energy. Although it’s difficult to tell how long it will take there will be a point where climate change will accelerate faster than our ability to manage and then billions could die. Geo-engineering can slow or reverse climate change and give us a chance to get the technology together to reduce greenhouse emissions and manage our atmosphere.
– Climate change will cause global economic instability which could easily overpower the imperative (or the ability) to change energy sources. If people are dying or starving they won’t give a rat’s ass about arresting climate change. If we can stabilize the earth’s temperature we can prevent the widespread chaos that would scupper efforts to transform the world energy economy.
– It may not be possible politically or economically to cause enough reduction in greenhouse gasses to prevent global warming in the time we have. There’s been significant loss of rainforest due to overfarming and overpopulation which may mean that it’s an unattainable goal no matter how well we work together. Geo-engineering may be the only way to prevent widespread damage due to climate change given the objective realities of the situation.
– It’s not agreed that greenhouse gas emissions are the main cause of global warming. It’s entirely possible that changes in the sun or other unknowns could be causing climate change in which case we could spend trillions on reducing greenhouse gas only to see the climate still getting hotter. Increasing the earth’s albedo is a sure-fire way to reduce the earth’s temperature.
In a medical emergency the first action should be to stabilize the patient, to keep them alive until a long-term soution can be found to their problem. Mother nature is no different: she needs first-aid right now, not major surgery.