Now, let's talk about climate change, climate negotiations, the @IPCC_CH, and why we should be in a better place by 2030. First off, it's worth remembering what a hole we were in ten years ago. COP15 Copenhagen had just collapsed. My eldest daughter was the youngest attendee!
Copenhagen was framed around a fallacy: climate negotiations as a one-off prisoner's dilemma, so any solution means ceding power to transnational government to share out and enforce emission budgets. As I wrote in 2007, it's a repeated prisoner's dilemma. [A fascinating piece: read it]
At the time, I had not heard of Elinor Ostrom's work. She too had no time for the Copenhagen approach, proposing instead a "polycentric" approach, based on action at every level: local, regional, states, nations, businesses, individuals. Sounds like Paris!
COP25 Madrid flopped, but the past decade delivered Paris: “Paris is not posturing. Paris is not the world saying it wishes it weren’t trapped in an abusive relationship with the fossil fuel industry; Paris is the world’s economy serving divorce papers.”
Over the past 3 years, the Paris framework has been progressively embedded into the political, social and business landscape around the world. Boris Johnson’s 2050 net-zero commitment? Paris. 77 countries committing to net zero? More Paris.
President Trump has, of course, capriciously initiated the process of withdrawing. However, its citizens, states, cities and businesses are doing an end-run around him, effectively honoring the deal without the support of the Federal government. Classy!
In Madrid the U.S. argued that it must be forever allowed to continue policing the ‘loss and damage’ provisions, so that they can never be used to seek compensation from fossil fuel producers. No sir! Once out, the U.S. loses its seat at the table.
One of the big mistakes of climate diplomacy of the past 40 years has been to treat it as an environmental issue, instead of what it is: industrial and trade policy. The U.S. is about to voluntarily abandon a vital diplomatic battlefield. Silly Donald.
Stakes are high for #COP26 in Glasgow next year. It will need to restore trust lost in Madrid, pass rules on international carbon credits and usher through the next set of Nationally Determined Commitments. No one better to trust than @Cop26President!
In many ways climate diplomacy will look very similar in 2030 to today: consensus around the need for action, a growing body of rules, an increasing level of ambition and commitment, but a high level of frustration at the inadequate rate of progress.
While climate diplomacy may still look similar in 2030, climate science will not. Sadly, we will have had to give up hope of keeping to 1.5C of temperature increase. But the catastrophism of the last few years will have passed too. Let me explain...
It turns out that the most catastrophic climate outcomes, ubiquitously described as baseline or business-as-usual by climate scientists, journalists and activists, are not where we are headed, but represent an extreme and highly implausible scenario. To ensure different teams of scientists around the world produce comparable outputs, @IPCC_CH uses a standard set of scenarios or RCPs, with different levels of radiative forcing in W/m2 by 2100. Historically, the IPCC gave them all equal probability.
For its 5th major Assessment Report in 2014, this changed. The most extreme scenario, RCP8.5, is the only no-mitigation scenario in the ensemble - the others all assume some level of mitigation. So it's hardly surprising people started using RCP8.5 [or 3.7 degrees C] as BAU ['Business as usual. RCP8.5 was never meant to be the BAU base case]
When RCP 8.5 was originally developed, it was described as "a relatively conservative business as usual case with low income, high population, and high energy demand." And that energy demand is met in RCP 8.5 by coal. Lots of coal. Lots and lots of coal.
At the time it was developed, in 2011, maybe RCP8.5 looked justified, because of recent surging emissions, driven by the industrialisation of China. But now the 7x increase in coal use per capita by 2100 in RCCP8.5 looks ludicrous. (HT @Peters_Glen)
In 2017 @jritch and Dowlatabadi showed why "vast expansion in 21st-century coal consumption should not be used to describe any plausible reference case of the global energy future." Basically there's not enough economically recoverable coal in the ground!
To reach RCP8.5 levels of radiative forcing by 2100, atmospheric CO2 would need to reach 1,100 ppm (315ppm in 1959, it's 411 ppm today). Extrapolating linearly gets to 540ppm. Adjust for recent acceleration in rate of increase, and you get about 650ppm.
What about feedbacks? The difference between 650ppm and 1,100ppm by 2100 would require the release of many hundreds of gigatons more CO2. There are no feedbacks I have found in the literature that can deliver this amount in the 80 years between now & 2100.
We need to get MUCH cleverer in thinking about feedback. As @jrockstrom says: "there are two time-scales that matter when it comes to climate change. One is the deployment time-scale, the other is the full impacts time frame, which unfolds over centuries." And we do NOT want to push the buttons which start irreversible change.
In other words, it is legitimate to worry about feedbacks and tipping points, but NOT legitimate to model them using an implausible concentration scenario for 2100. Give unto 2100 what is 2100s! For century time horizons, Real Options probably beat the precautionary principle.
Just last week @hausfath and @jritch extrapolated the [in my view pessimistic] @iea CPS & SPS scenarios to 2100, and conclude "the world is on a path to warm around 3C above pre-industrial levels by 2100 under policies and commitments currently in place."
This is much closer to RCP4.5 than to RCP8.5. As they point out "this is a far cry from the 1.5C and 2C targets enshrined in the Paris agreements, but is also well short of the 4C to 5C warming in many “business as usual” baseline scenarios that continue to be widely used."
Don’t get me wrong. The world of RCP 4.5 is an ugly place, with warming of 2.0C to 4.5C by 2100. We absolutely must bend the arc towards the lower end of that range, or below. But it's not the 3.3 to 7.4C of RCP8.5, which generate most of the news stories.
If we have to act just as urgently, why does any of this matter? First, a robust coalition for climate action can only be built on bullet-proof science. When @IPCC_CH IPCC Assessment Report (AR6) appears in 2022, it cannot rest on implausible scenarios.
My comments:
- I don't have access to sophisticated climate models. So I did a "back of the envelope" calculation about the likely rise in temperatures over the next 50 years. Since the late 1970s, global temperatures have been rising by 0.2 degrees C every decade. If we manage to cut emissions to zero by 2050, then temperatures will rise by another 0.6 degrees. If we take longer, then the rise will be higher. And even after we achieve zero emissions, the thermal capacity of the oceans will likely give us another couple of decades of rising temperatures. In other words, another 0.8 degrees.
- The 1 degree which has taken place so far is bad enough; another degree would be exponentially worse. Even if we don't see a 4 or 5 degree rise, things will still be very unpleasant. Ask anyone living through Australia's current record heatwaves and bushfires. All the same, 2 degrees is better than 4.
- The IEA's forecasts for the growth of renewables are always too low. They reckon 2.7 degrees. So the probablity is that it will be lower than that.
- The polycentric approach (individual, local, regional, national, companies, institutions) makes a lot of sense. Despite denialism and denialists, as temperatures rise and as the effects of global heating/climate change become more serious, the pressure to act will intensify. But if we wait for global collective decisions, nothing will happen. We must all do our bit. You could take an easy step—become vegetarian. 24% of global emissions come from agriculture, much of that from raising livestock to eat. Choose a green electricity provider, but check first that its credentials are real—a utility which just buys carbon offsets is greenwashing. Buy an electric car—they're going to get a lot cheaper. Push your municipality, your state and province, your nation, to cut emissions as fast as they can. And vote against denialist parties. By acting on multiple levels we will prevent the global rise in temperatures from exceeding a (dangerous) 2 degrees by 2100.
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