Imagine a highway full of cars, all traveling at very high speed, and all of them simultaneously going out of control. Something along those lines may be in store with climate change if we can't very quickly decarbonize our economies and our societies.
I've done a few online courses in climate change, fairly mundane stuff. I'm doing one now that's head and shoulders above the rest. This course is being presented by experts from the Potsdam Institute for Climate Impact Research, one of the most prestigious organizations in this field. The Potsdam Institute is funded by the German government. This course is funded by the World Bank.
This week's lectures explore what awaits us if, despite all the warnings, our governments allow 4 degrees Celsius of warming which, by the way, is what the consensus concludes is likely to happen. I prefer to go through the week's lectures non-stop so I don't fall behind and can avoid the necessity of reviewing everything at week's end before taking the test.
Much of the information is pretty well known to anyone who reads news reports - sea level rise; disease and pest migration; both cyclical and sustained drought and flooding and so on. Other impacts are less well known but equally problematical.
Rate of change is something not commonly discussed yet it should be central to our governmental responses. Some impacts will be gradual, linear and mild. Others will be abrupt, potentially severe and unpredictable. The critical point to take from this is that we really don't have the luxury of time to waste in taking effective action. We're not overtaken by events beyond our control yet, not yet, but that point is far closer than most of us seem to believe.
Carbon capture and sequestration. Leaving aside all of its drawbacks and pitfalls, CCS probably won't be ready for large scale implementation until around 2025. However it will then take at least two decades to implement on a scale that will even remotely put a dent in our emissions problems. That's time we just don't have. In other words it could turn out to be a gimmick, a blunder with enormous consequences if we cling to the faint hope of CCS instead of going cold turkey on fossil fuels as quickly as possible.
One lecture discussed the "cascade." This describes the synergy of climate change impacts on other climate change impacts. In effect they become greater than the sum of their parts. Some of these challenges include the loss of coral reefs triggering a collapse in marine biodiversity; abrupt changes to the Indian Monsoons, the melting of the Greenland ice sheet (itself being accelerated by black soot from wild fires in the tundra and Boreal forests); the potential collapse of the Amazon rainforest and the effects that will have not only on natural carbon sequestration but also precipitation patterns (Sao Paulo, etc.); the retreat of glaciers, especially in the Himalayas and Hindu Kush; the decline of the Atlantic Ocean conveyor; and something called the marine biological carbon pump. To these you can add sea level rise, ocean acidification, biome loss (habitat destruction) and so on. At some point we have to anticipate some or many of these impacts sort of ganging up on us, each bolstering the others, and that is going to be a wild ride.
Two new terms entering popular lexicon are "3 Sigma events" and "5 Sigma events." 3 Sigma events are what we now consider rare, extreme weather events. They're severe but we've endured them in the past. They're going to become the new normal. They will increase in duration, intensity and frequency.
5 Sigma events are coming. We've had no experience of them. They're unprecedented and and will render some parts of the world (the tropics and mid-latitudes of the northern hemisphere) uninhabitable. Toward the latter part of the century these will become common.
By about 2080 the coolest summer months are projected to be "substantially hotter" than the warmest month we've known in human history. As for the hottest months, fortunately most of us won't have to deal with that.
Ecosystems are changing everywhere, especially in the Arctic. In temperate latitudes, Spring is now arriving 2-weeks earlier than the historic normal. Crop zones are shifting away from the equator. Frost line defences are failing, enabling the migration of pests and diseases.
As for the 2C target, getting ourselves on track to limit warming to 2C by 2100 has many payoffs ranging from giving ourselves vital time to implement adaptation strategies to giving species in peril essential time to migrate and avoid some loss of biodiversity.
There was a discussion about the need to move promptly on upgrading and replacing infrastructure that was designed and constructed for the demands of a climate that is now gone and won't be returning. We need to design infrastructure to meet the climate loads that will be here in just a decade or two and that's a huge challenge.
Those are some of the most salient points covered in this week's lectures. They're pretty stark, especially in the context of what awaits us if we don't act boldly and without delay. Do we have the will to do that? I have my opinion as I'm sure you have yours.