How to think about global warming, by a conservative

An interesting piece from The Guardian, written by Jerry Taylor, previously a full-on denialist, now recanting his obscurancy.  

For 23 years, I worked at a libertarian thinktank, arguing against climate action. But my views have changed. I now embrace decarbonization. Why? For one thing, I’ve come to better understand risk management.

The raucous political debate with denialists aside, the real debate in climate science is about how much warming we’ll have to face, how abrupt it might be, how quickly we can adjust, how much severe weather we’ll experience, and how likely it is that various low-probability, high-impact climate events will come to pass.

Uncertainties persist because scientists are still unsure how sensitive the atmosphere is to greenhouse gases. Evidence from the peer-reviewed literature suggests that a doubling of greenhouse gas concentrations above pre-industrial levels (which we’re likely to see sometime after mid-century) will probably warm the planet anywhere between 1.5C (2.7F) and 4.5C (8.1F).

There’s a world of difference between those “likely” low-end and the high-end estimates. “Lukewarmers”, such as the journalist Matt Ridley, contend that warming will be at the low end and prove of little consequence. Many scientists, however, have little patience for those arguments, arguing instead that warming is more likely to be at the higher end, with global environmental and economic convulsion the likes of which we’ve never seen.

Like many in the climate arena, I got caught up in this debate, and the uncertainties surrounding climate change allowed me plenty of fodder to argue my case. But I finally came to the realization that the debate about what’s most likely to happen will not take us very far. That’s because humanity’s response to climate change is an exercise in risk management – and risk management is not about discerning the optimal response to the most likely outcome, it is about determining the optimal response to the full distribution of possible outcomes

In his recent book, economist Richard Tol (who I used to cite when I wanted to push back against aggressive climate action) offers three reasons why – even if you think climate change is an overblown concern – we should hedge our bets.

First, surprises are weighted toward the bad. Despite some technical ambiguity, scientists believe that the chance of a nasty surprise is much greater than the chance of a pleasant surprise. Second, the risk of locking ourselves into a high-carbon, worse-than-expected climate world is larger than being locked into overly expensive zero-carbon energy. That’s because once CO2 is in the atmosphere, it will stay there for centuries, and is very expensive to remove through technical means. Zero-carbon energy facilities, on the other hand, can be retired rather easily if need be, and will at least deliver significant health benefits regardless of how climate change plays out. Third, we have rightly demonstrated a willingness to pay in order to avoid incurring risks that are asymmetric, ambiguous and irreversible. Global warming is all three.

[Read more here]

Yes.  There's the risk of getting a forecasts wrong, and there's the risk to society if the forecast is right.  If a doubling of CO₂ leads to just a 1.5 degree rise in global temperatures then that's one we can live with.  But the equally probable 4.5 degrees would be a catastrophe.   So really, what we need to look at is risk times consequences.  And then we need to look at costs.  The costs of switching to renewables and to EVs is low—renewables are cheaper than coal and EVs will within a few years be cheaper than ICEVs.  These are the "low-hanging fruit".   Setting these costs against the risk multiplied by consequences of not acting makes the decision obvious. We switch to renewables and EVs as fast as we can. 

Other stuff (cement production, iron and steel, air travel, agriculture) will be harder. I believe, however, that as the evidence of global heating increases, society will become more willing to stop emissions from these activities too.  The pressure to act is only going to increase with every drought, every heatwave, every flood.  The Overton window on global heating is shifting faster than ever.

Source: Planet3.org