Human beings are responsible changing Earth’s climate – and that is a bad thing – both for us and the planet. However, in a curious sense, it’s also good. Many species have faced extinction in the past from naturally occurring climate changes that they were powerless to avoid. However, as the first species in Earth’s history to be intentionally bringing about its own destruction, homo sapiens are also the first species that could save itself.
To put it another way, anyone who insists that our changing climate is the result of natural processes is not only factually mistaken, they are underestimating just how powerful humanity has become, and in doing so are throwing away our best chance of getting out of this mess.
Clearly, one way to do this is drastically cutting our greenhouse gas emissions to allow the Earth’s climate systems to return to a sustainable equilibrium. While some greenhouse gasses remain in the atmosphere for millennia, others (including methane and hydrochlorofluorocarbons) are more quickly reabsorbed.
Still, even a complete cessation of all greenhouse gas emissions would mean considerably more warming that we have already experienced as the climate adjusts to the emissions we have already produced.
This would be a very good idea, however, it is not our only option. We could also attempt to engineer Earth’s environmental systems to directly counter the impact of greenhouse gas induced climate change.
One way to do this is by altering ecological and geological systems to reabsorb greenhouse gasses more quickly. For instance, fertilising the oceans may increase the number of photosynthesising organisms in them and hence the rate at which they turn carbon dioxide in the atmosphere into fish food. Another is by reflecting more of the heat radiated from the sun back into space. For instance, injecting sulphate aerosols into the upper atmosphere will cause the Earth to reflect substantially more sunlight before it has time to reach the ground and cause global warming.
Both of these processes effectively mimic naturally occurring events, such as algal blooms and super volcanoes, but on a larger scale and over a longer period of time. While each has its own advantages and disadvantages, there is no shortage of reasons why any of them would be a terrible idea
Firstly, climate change is highly complex, and geoengineering solutions can, at best, only tackle one part of it at a time. For instance, carbon dioxide is just one of many greenhouse gases that cause climate change, so removing it will not solve the whole problem. Similarly, whilst climate change is increasing global surface temperatures, this is not a uniform process, and simply cooling the entire planet will not ‘undo’ this change. Experience should have taught us long ago that focusing on just one aspect of complex environmental problems seldom makes things better, and can often make them worse.
Secondly, geoengineering will have significant impacts of its own, altering the chemistry of our atmosphere and oceans, damaging human agriculture and natural habitats and producing ecological stressors are likely to damage important ecosystems.
Thirdly, geoengineering, in any form, will have systemic impacts that affect the whole world. We cannot hope to localise the impacts of our activities to any one region or community, so many people are sure to lose out, and it will be impossible to undo any harm caused to them.
Fourthly, because of its global impact, geoengineering is liable to cause global conflict. The raw materials for engineering the global climate (mostly either powered iron or sulphate aerosols, plus a few boats and balloons) are readily available and remarkably cheap, and it will be much easier to introduce them into the environment than to remove them later. This makes it likely that those countries who stand to gain the most (or lose the least) from geoengineering will dictate how much is produced.
Finally, if, for any of these reasons, we decided several years down the line that geoengineering should be turned off after all, and were able to achieve this, this could still bring problems of its own. One of the things that makes climate change so dangerous is the speed at which it occurs, and in the aftermath of turning off geoengineering, it is likely that we could see changes to the Earth’s climate that were far faster than any we had previously known – with potentially catastrophic consequences.
So, geoengineering is a very, very, very, very, very bad idea. It should form no part of any sensible strategy to mitigate the expected effects of climate change. However hard it might be, cutting our greenhouse gas emissions is the only sane way to stop anthropogenic climate change…
And yet we may still have to do it someday. Why? Because sadly we don’t live in a sane world. At present, we are still at a stage where it is likely that a drastic cut in greenhouse gas emissions would lead us back to a climatic equilibrium that is similar to what we experienced during pre-industrial times. However, we cannot take that for certain in the future. There are many processes, physical, chemical and ecological, that could tip the balance the other way so that we would find ourselves crossing a ‘phase shift’ where climate change became self-perpetuating and positive feedback drives us towards an even warmer future, whether we carry on emitting greenhouse gases or not.
The geological record provides us with substantial evidence that such tipping points exist, and that the Earth’s climate has crossed them in the past. However, it provides us with few clues about where they are or what causes them. At present, therefore, we are driving in the dark, and we have little idea how close we may be to crashing over a global climatic cliff.
Doing so, however, would fundamentally change the rules of the game for humanity. It would give us no choice but to either accept an inevitable shift to a much warmer world, which could well be ‘beyond catastrophic’ for us or else find some way, such as geoengineering, to push back against the natural forces pushing us towards a hotter planet.
People often worry that even the possibility of geoengineering may provide some with and excuse for not doing more to curb greenhouse gas emissions. Personally, I am coming to see things in a very different light. Despite its many problems, we should be working to understand geoengineering so that we know how to use it, how to control it, and how to mitigate its worst effects should we ever have to utilise it in the fight against truly catastrophic climate change.
However, the more we understand it, and just what a very, very, very, very, very bad thing it might be, the more we should feel determined to make sure that the conditions under which we might need it never come to pass.
Let’s just make sure we stop climate change while we are still the main thing causing it.
HuffPost UK Tech has launched HuffPost-Apocalypse, a project that aims to investigate what an apocalypse would mean for humanity, how we can best delay the end of the world, what the world will look like after we’re gone and what the best viable options for survival will be for anyone left. Join in the conversation with #HuffPostApocalypse on Twitter. To read more from the series, visit our dedicated page.