Guest essay by Alberto Z. Comendador

As the US weighs whether it should withdraw from the Paris agreement, a critical question is how effective have climate change policies been so far. A failure of the policies adopted until now doesn’t necessarily mean that future policies will likewise fail, but it will provide further evidence that decarbonizing is, well, difficult. And expensive.

One routinely hears comments that the US is the country most affected by climate contrarians / denialists, and that in other parts of the world (most notably Europe) this debate doesn’t exist, there is consensus about the need to act, etc. To quote a German citizen:

‘The 97% of climate scientists who agree on the basics include many conservative scientists. That there is a problem is not a partisan issue. How to solve it, that is politics. The Paris climate agreement was signed by nearly 200 countries and thus many conservative governments. They accept that climate change is a real problem. European conservative parties may be less active, but do not deny there is a problem.
In Europe only Trumpian racist parties deny there is a problem. That the climate “debate” is mostly an American problem shows that the problem is not conservative versus liberal, that it is not a lack of scientific evidence, it is not a problem of the communication of science. The problem is the corrupting influence of money in US politics and media.’

I take him at his word.

Germany is the country with the strongest consensus around the need to ‘do something’ about climate change. No other nation has started an ambitious a plan as Energiewende. The program started in 2000 and set an objective for 2050 – though bizarrely, as is common with these ‘plans’ and ‘roadmaps’, the objective is stated in absolute greenhouse gas emissions rather than the emission intensity of the economy. It’s easy to see the problem:

a) If emissions by 2050 are higher than the plan stated, advocates will claim that this happened because economic growth was stronger than expected. In other words: advocates could claim climate policies succeeded in making emissions lower than they would otherwise have been. Of course advocates of emission cuts never clarified how much economic growth they expected in the first place, so this claim is completely unfalsifiable.

b) If emissions by 2050 are the same or lower than the plan stated, advocates will claim success for the plan – even though the decline in emissions may in fact be due to economic crises and/or population decline.

Not to sound repetitive, but the only measure of progress that makes sense is the emissions intensity of GDP. In particular, how much this intensity declines per year. In this article I will show a positive number, i.e. how many more dollars of GDP per ton of…