Winter might not be coming

19/10/2018

 Or when it does, it will increasingly be in a much-reduced form.  As much of the northern world has seen this year, summer can arrive with much more of a vengeance.

This is not good news and as any climate scientist will tell you, it’s certainly not fake news.  Our weather is changing.  Greenhouse gas emissions due to industrial activity and the conversion of forests and savannas to agriculture are the principle drivers of the currently massively observed changes in climate. Our understanding of the science that underlies this is not perfect, but it is as exact as any other area of science that brings mathematics, massive amounts of data, and hugely replicated experiments together.

We all check the weather forecast every morning and it gives us an accurate assessment of what the weather will do for the next 20 to 48 hours. Exactly the same set of models were used to make predictions of how the climate will evolve as we add greenhouse gases to the atmosphere. Imagine how much wealthier we would all be, if mathematical models for the money markets had this level of predictive skill. Yet, some politicians seem happy to see hedge fund dealers as mathematical geniuses, while simultaneously denigrating climate scientists. This is of course a travesty driven by a mixture of ignorance and large political donations from those with a vested interest in not taking the blame for climate change.

Similar situations arose when it was pointed out that there were significant health effects associated with smoking tobacco.  Hopefully, the companies who have been driving and denying climate change will eventually face legal settlements that parallel those paid by tobacco companies.  The bill this time will be much, much higher. So maybe the politicians who accepted donations from the oil companies will have to help foot the bill.  Or possibly also the children of energy industry magnates and their political concubines?  Not least because climate change, as with all forms of environmental change is an inter-generational problem.  One where the “sins of the fathers” will be hugely reaped by their offspring.  Potentially, climate change may eventually precipitate new legal precedents for collecting intergenerational compensation.

When the climate change debate first started in the late 1980’s several high-profile meetings examined both the available evidence for climate change and the possible consequences.  Those who seek to cast doubt on the accuracy of the predictions will find it instructive to go back and read some of these documents (Dobson, Jolly en 1989, Schneider 1989, Peters, Lovejoy 1992, Root, Schneider 1995). One again wishes that our highly revered economists were as accurate in their predictions!  Many of the climate driven events we have seen in the last few years were consistently predicted during the earliest discussions of climate change: declining Arctic sea ice, increased frequency of summer heat-waves, significant predictions in levels of precipitation significant changes in annual and seasonal precipitation which will impact crop yields and food prices.  The only major error in these analyses was that these impacts were predicted to occur much later in the century. Part of this was expediency, the climate scientists did not want to appear unnecessary alarmist, but there was also a significant belief that climate would respond more slowly to an accumulation of greenhouse gasses than we are currently seeing. Part of it also reflects the further accumulation of greenhouse gasses in the atmosphere over the last quarter century.  To me, the scariest thing about climate change, is that everything predicted is occurring much earlier than was originally predicted.  As climate is a highly non-linear system, this means that future weather events will quickly attain new extremes.  So we can either bury our heads in the sands of our primitive belief systems, or we can try and precipitate political and social change to slow climate change before it is too late to reverse it.

The Rockies Institute provides a vital forum for these discussions.  Its primary goal is to educate people about the consequences of climate change while also fostering research that looks into their impacts in the Canadian Rockies, particularly the impact on those living close to the land.  The impacts of climate change will have a subtle underlying geographical variability.  Temperature will rise much more rapidly in the Artic regions, than in the Tropics.  The rapid decline in Arctic sea-ice provides strong testimony to this. This in turn creates a set of secondary feedbacks: as the tundra melts, it will release large amounts of stored CO2 that will enter the atmosphere and further enhance rates of warming.  Similarly, the huge fires than have been burning over the past few summers in Canada’s boreal forests add more CO2 back into the atmosphere.  The decades it will take for these forests to regrow emphasize that it is much harder to remove greenhouse gases from the atmosphere, than to put them up there in the first place. 

At first sight mountains would seem to be pre-adapted to deal with climate change. If the earth gets warmer, than plant and animal communities can simply move upslope and colonize areas that correspond to the climate they used to experience. The problem here is that montane vegetation disperses only very slowly and of course mountains tend to get smaller the higher up them you ascend. This means that montane habitats will get smaller and support less diverse communities of plants and animals if their only recourse is to migrate upslope. Much larger challenges face species living in the prairie; the distances they will have to move to find the climate conditions they are adapted to may move many hundreds of miles and the soil quality will inevitably be poorer as it has been covered in thinner layers of vegetation for centuries and thus has thinner layers of soil for plants to grow in. This change in soil quality will also undermine any delusions that significant new agricultural areas will open up in the once boreal areas of Canada and Russia.  Similarly, increased access to fisheries in the Arctic will be undermined by the problem that marine productivity in Arctic regions is driven by refraction of light into planktonic regions at the edge of the ice. If the area of sea ice shrinks, it’s perimeter will shrink and the future of Arctic fisheries will be rapidly curtailed.
 

What can be done to slow climate warming? First of let’s underline that there are no viable easy technological fixes. This makes fixing climate change, much harder the related problem of atmospheric ozone that created holes over the Arctic and Antarctic that began to expand and allow harmful levels of ultra-violet light to pass through the atmosphere. The industries that created the ozone problem (largely refrigeration), also had the solution; replace fluorocarbons with alternative chemicals. Policy changes, specifically the Montreal protocol, could thus be quickly adopted and initiated as the people who’d created the problem could enhance their profit by adopting its solution.

Climate change presents more significant policy challenges, that will certainly require a range of solutions, as presented by Pacala and Socolow  in Wedges: Solving the Climate Problem for the Next 50 Years with Current Technologies. Some energy companies are investing in photovoltaic energy, but initial subsidies that helped initiate this have been killed, largely due to political pressure from companies who can continue to profit from oil and gas. Slowing and reversing rates of land conversion provide another option, this will require increases in agricultural efficiency, so that more crops can be grown on land already converted from pristine forests. But this needs to be accompanied by significant amounts restoration, particularly the conversion of degraded agricultural and industrial land back to forest and savanna covered in plants that suck CO2 out of the atmosphere and store it back in the soil. Land restoration and preservation needs also to be undertaken in ways that allow plant and animal species to disperse across the landscape in response to climate change, and potentially back again, if we manage to control climate change. But this is a very big ‘IF’. It requires political will and societal belief, neither of which will be easy to inspire in systems that take many electoral cycles to show effects. Anything we do now to modify climate change, will not have an effect for at least 25 years.  There are very few precedents for legislating for events over such prolonged time horizons. Yet the consequences of not acting will be increasingly dire for children born this century. Winter may not arrive at all for their children; but summer will become relentless. 

reagissez !

Ajouter un commentaire