It is reassuring to see the Royal Geographic Society kicking off the new year season of Monday night lectures with one on the subject of climate change, delivered by the newly ennobled and eminent Dame Julia Slingo, the chief scientist at the UK Met Office.
Guardian headline warning: UK Storms Batter Coast During Christmas 2013
Professor Slingo is an establishment figure who has worked tirelessly in developing the worldwide reputation of the Met Office, as a leading institution with the ability to analyse both regional weather and develop our understanding of climate change. In this lecture, she set out to explain how her stable of over 500 scientists have been working to build powerful computer models that can simulate climate and tell us what the far reaching effects of climate change are going to be.
After several demonstrations of how the models have performed compared with actual observations in recent years, Professor Slingo then vented her annoyance when people criticise the models and the results that they produce, describing them as her “laboratory,” where she and her colleagues go to study the climate. There is a direct correlation between the accuracy of the models and the computing power driving them. Recent years have seen enormous advances in the ability to model our atmosphere in much greater detail. The models rely on data from many sources, such as atmospheric greenhouse gases, moisture in the air, the movement of the thermohaline circulation, storm tracks and intensity, and so on. The more data fed into the model (and computing power available to process it), the better the results.
In terms of the IPCC report published every 7 years, Professor Slingo reassuringly made the point that this is not frequent enough in terms of being able to inform policy, as the weather and climate operate in real time, constantly responding to an almost endless number of feedbacks that cause changes. The need for ongoing analysis and developing intelligence is vital.
This neatly set the stage for the main core of the lecture: the growing need for understanding of climate change for everyone from policy makers, farmers, vulnerable populations, insurance companies and, as most of us around the world have recently experienced in various forms of extreme weather events, us the public. We are all, she says, potential climate “customers” of the Met Office. This concept has led to greater collaboration with the UK government who are funding the development of the models, based on a principal that money can be made from the creation of such valuable knowledge (which is true!).
Professor Peter Wadhams, Professor Martin Rees And Dr Hugh Hunt discuss emissions, temperature and carbon dioxide removal.
But is there a fly in the ointment? The IPCC report has set a “target” of 2 degrees centigrade as a safe level of warming that human civilisation can go to before climate change becomes dangerous. Having myself interviewed many scientists working on Earth’s sensitivity to temperature, it seems that this figure of 2C has very little grounding in climate science at all. The Earth, as Professor Slingo pointed out, has warmed 0.8C since preindustrial times. We know that the planet takes many years to catch up with the level of greenhouse gases in the atmosphere, so the 0.8C we are experiencing now (coupled with ever increasing extreme weather events) are just the beginning of what we have in store.
Temperature will keep rising even if we manage to stop emitting gases such as carbon dioxide and methane right away. The other trouble on the horizon is that as the Earth warms, it triggers other feedbacks within the system that then accelerate the warming further. These feedbacks are many and still not fully understood. However, what we do know is that many of them are not included in the models and scientists doing work in this area are concluding that even warming of 1.5C is likely to trigger feedbacks that could accelerate warming to more like 4-5C and rising. A good example is the warming of the Arctic and the loss of sea ice. The rapidity of the loss of sea ice was predicted by scientists such as Professor Peter Wadhams who had been studying the thinning of the sea ice volume, in addition to the reduction in area (satellites only capture the extent/area, but the volume has been measured from submarines able to move beneath the ice) over several decades. Strangely the models disagreed with what the eye could see and were still predicting a much more gradual loss, leading to an ice-free Arctic somewhere around 2080. These figures have been revised back to about midcentury but still seem to lag what is actually being seen with first hand observations.
Temperature will keep rising even if we manage to stop emitting gases such as carbon dioxide and methane right away. The other trouble on the horizon is that as the Earth warms, it triggers other feedbacks within the system that then accelerate the warming further. These feedbacks are many and still not fully understood. However, what we do know is that many of them are not included in the models and scientists doing work in this area are concluding that even warming of 1.5C is likely to trigger feedbacks that could accelerate warming to more like 4-5C and rising. A good example is the warming of the Arctic and the loss of sea ice. The rapidity of the loss of sea ice was predicted by scientists such as Professor Peter Wadhams who had been studying the thinning of the sea ice volume, in addition to the reduction in area (satellites only capture the extent/area, but the volume has been measured from submarines able to move beneath the ice) over several decades. Strangely the models disagreed with what the eye could see and were still predicting a much more gradual loss, leading to an ice-free Arctic somewhere around 2080. These figures have been revised back to about midcentury but still seem to lag what is actually being seen with first hand observations.
The main point here seems to be that the principals by which the Met Office is getting ready to inform policy and global awareness of climate change are seemingly very flawed. There was a sense in the audience that 2C was a target that we are going to achieve and that as long as we have the models to guide us through then we will be able to adapt. Professor Slingo produced a slide with the words “mitigation and adaptation.” In other words, let's stop producing greenhouse gases from burning fossil fuels and agriculture, combined with accepting a certain level of climate change that we’ll adapt to. Various photographs of farmers and people in worst affected areas were shown to reinforce this point. Perhaps worrying to me is the fact that these images make climate change appear as if it is a problem for the rest of the world and that we, crammed into the Kensington auditorium, have quite a lot less to worry about.
Part of the IPCC discussion has centred around the idea of an “emissions budget,” which equates to how much more carbon dioxide we can emit before we have to stop, in order to avert dangerous climate change. Dates are being set a decade or two from now as the timeline that we have to work to. It would be interesting to know how these figures are reached because, again, climate scientists looking at the level of warming we are due from what we have already pumped into the atmosphere, know all too well that there is no budget left. We are way past the level of safe concentrations of greenhouse gases in the atmosphere. Mitigation is a must, but it will not be enough. Adaptation to extreme weather events and destabilisation of the Greenland and Antarctic ice sheets mean that we are moving into a very different planetary system. For many people around the world surviving, let alone adapting, is going to be a very serious challenge. Those of us in more temperate climates will face the knock-on effects of unstable climate, resource shortages and climate refugees.
Another hot topic that is now being discussed by many scientists and engineers is the need to start drawing carbon dioxide down from the atmosphere. If we could extract the gases from the atmosphere, bringing the concentrations down from the current 400 parts per million (ppm) to somewhere near 320 ppm (preindustrial levels were 280 ppm), then we would stand a better chance of restoring the climate to something like that which we’d be happy to call “home.” This is no easy task, as the amount of gases we currently put up into the atmosphere is far greater than any other material we handle on the planet. This doesn’t mean we shouldn’t try, but it does mean it won't happen over night. Carbon dioxide removal is the essential third title to add to “mitigation and adaptation.” However, mitigation itself is currently a pipe-dream as humanity is ramping up its emissions, as opposed to bringing them down. Even the IPCC “business as usual” scenario for greenhouse gas emissions states that we will hit 4C warming by the end of the century. Add in accelerated heating from multiple feedbacks (many are absent in the climate models) and this figure doubles and then triples. Welcome to the inferno!
To return to the Met Office climate modeling, it seemed more clear that this talk was about selling to us, the public, the idea that somehow the models are going to navigate us through this climate change challenge. I don’t personally find it very reassuring. The fact that an impaired and approximate simulation of our hugely complex planetary system becomes the bedrock of reality from which we plan our futures in the real world seems more like a form of escapism. Models are vital but they must be much more powerful than they currently are and much more detailed. They must also not seek to downplay what is going on in the real world which we know from observation. If we go down this route, then we are really entering the world of fantasy, and there does seem to be much of it around at the moment.
In a discussion with friends who have no special interest in climate change, after the lecture, they seemed a little vague as to what they were meant to have taken away. The subject seemed so vast that it was best left to the experts. This again is great mistake. Climate change is an issue that is effecting us now and will continue to do so in ever greater ways. It is essential that we demand robust information and effective policy from those who are in a position to deliver it. Of course, the old adage said by many environmentalists that there is no “planet B” could be wrong. The Met Office models may be a far safer place to live than down here on Planet A... let’s hope so!
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