So what brought me to the conclusion that catastrophic climate change is now unstoppable and the collapse of human civilisation inevitable and probably a matter of decades away. Well here’s a brief summary of my thinking.
It’s probably just about possible to prevent catastrophic civilisation ending climate change but it ain’t going to happen. It would require creating a zero carbon emission society almost immediately and at the same time rolling out a massive program to remove carbon dioxide from the atmosphere and store it safely forever using technology which has yet to be invented. Both of those would require a complete transformation of how we organise our economy ie the ending of capitalism, everywhere, almost immediately. And that just isn’t going to happen.
Are we really in such a dire situation? Yes. And here’s why.
First off the 2C so called safe limit of warming agreed by most of the world’s governments isn’t actually safe at all. It was a limit not based on climate science, but on what economists thought they might be able to get politicians to agree was practicable and it turns out they couldn’t even do that.
No amount of warming is truly safe but probably the upper limit that we could survive without too many dislocations is 1°C . Well we’ve already passed that. The first couple of months of 2016 were 1.3°C warmer than the 1880 baseline. But the industrial revolution didn’t start in 1880. That date was chosen as the baseline because that was when more reliable global temperature records started to be taken. The industrial revolution actually started around 1750 and scientists estimate that there was a 0.3° C increase in average temperatures between then and 1880. That means we’ve already breached the 1.5° C aspiration of the Paris climate change meeting. And given the inertia of the climate system (it takes about 10 years for the full warming effect of carbon dioxide to be felt after it is released into the atmosphere) we have a further 0.5° C of warming already locked in. So no matter what happens warming of greater than 2° C is now inevitable.
The other big elephant in the room is the dimming effect of burning dirty fossil fuels especially coal. The aerosol particles released from the smoke stacks actually dim the sun by absorbing heat and reflect it back into space. So perversely if we stop burning coal either in a planned manner as a consequence of efforts to reduce carbon emissions or unplanned as a result of social upheaval caused by climate change the aerosols and therefore their cooling effect will disappear in a matter of days. Scientists estimate that stopping burning all coal and other fossil fuels could increase the temperature by between 2-3° C .
Then we have the feedback effects. These are processes caused by climate change which then themselves cause greater warming. Probably the most commonly mentioned feedback is the ice albedo effect. Ice is white so reflects up to 90% of the solar energy striking it. However when it melts the dark blue ocean is exposed which absorbs about 95% of the energy hitting it.
The Arctic is probably going to be ice free in the next year or so and almost certainly by summer 2020 and the period it will be ice free will get longer and longer. The loss of the ice albedo will contribute another 1.6° C of warming.
To melt ice requires a lot of energy. In fact the energy required to melt 1 kg of ice would heat the same amount of water by 80° C . So all the heat which previously went into melting ice is now going to heat the oceans.
The next feedback is methane. At the moment the ice in the Arctic is trapping huge amounts of methane both in the soils under the permafrost and in the sea in the form of methane hydrates. As the ice melts the methane is released. In addition some scientists speculate that a huge methane burb could release 50 gigatonnes at one go from the oceans. Bear in mind that there are currently only 5 gigatonnes of methane in the atmosphere and that methane is 20 times more effective a greenhouse gas than carbon dioxide and you can just how far up the preverbial shit creek that would leave us. That would result in another 1.3 ° C of warming.
Then there is the soil carbon feedback (warmer soils mean that bacteria break down the carbon in the soil more quickly), the rainforest feedback (droughts mean the rainforest burns), the water vapour feedback (warmer air holds more water which is a greenhouse gas) etc etc. In all at least 19 self reinforcing feedback loops which amplify warming have been identified. That they are self reinforcing means that catastrophic climate change is now unstoppable.
So why aren’t the scientists saying this. Well some of them are. Guy McPherson being probably the best known. But their work generally doesn’t get reported although it is increasingly. Other scientists effectively come to this conclusion but can’t quite bring themselves to say there is no hope. Probably for professional and personal reasons. It is after all a very big deal to accept there is no hope and everything that you hold dear is going to end in a few years. It’s certainly something I struggled to come to terms with myself.
Scientists and indeed science is inherently conservative. The scientific method and the level of evidence required for a hypothesis to be accepted means that scientists generally err on the side of caution. Climate scientists even more so, due to the level of scrutiny their work is under from the fossil fuel industry and their denialist henchmen (and they are usually, although not always, men). There have been a number of pieces of research conducted which show that climate scientists consistently downplay their results.
Funding is also an issue too. Most climate scientists are employed by governments or universities. Reporting that we are all fucked in a matter of decades is not exactly going to make that next research grant or contract easier to win. It’s probably no coincidence that nearly all the scientists who publicly argue that the near term collapse of human civilisation is a distinct possibility are no longer dependent on those forms of funding.
Finally there is the make up of the leading authority on climate change the UN IPCC. It’s reports are agreed on by consensus, so every government in the world has to agree to their content which means that it is even more conservative than the scientists it is composed of. So for example it’s modeling of future climate change are those which are used by pretty much everyone else in their own research yet because they are not perfectly understood none of the feedbacks that I discussed above are included in their models.
Just how devastating that omission could prove was revealed in new research which investigated how quickly the climate changed in the past. It suggests that the climate is actually much more sensitive to carbon dioxide as the climate warms than previously thought. So while the IPCC Suggests warming of between 2 and 4 °C this century under a business as usual scenario this new research predicts warming would be between 4 and 7 degrees. And the research reports that in the past the earth has warmed by 5°C in as little as 13 years. And we are realising carbon dioxide into the atmosphere faster than at any time in the last 66 million years. Warming of somewhere between 3 and 5 degrees would mean that human civilisation can no longer be supported. Too many places would be too dry to grow enough food to feed us all. Given that we are actually exceeding the carbon emissions projections for business as usual and are likely to continue to do so for the foreseeable future that means human civilisation is f@$&ed. Easily within the lifetime of someone born today. Just how quickly I’ll discuss in my next post.