Steve Keen o ekonomii klimatickych zmen a IPCC
In his 2018 Nobel Prize lecture, William Nordhaus described a trajectory that would lead to global temperatures peaking at 4°C above pre-industrial levels in 2145 as “optimal” (Nordhaus, 2018a, Slide 6) because, according to his calculations, the damages from climate change over time, plus the abatement costs over time, are minimised on this trajectory. He estimated the discounted cost of the economic damages from unabated climate change — which would see temperatures approach 6°C above pre-industrial levels by 2150 — at $24 trillion, whereas the 4°C trajectory had damages of about $15 trillion and abatement costs of about $3 trillion. Trajectories with lower peak temperatures had higher abatement costs that overwhelmed the benefits (Nordhaus, 2018a, Slide 7). In a subsequent paper, Nordhaus claimed that even a 6°C increase would only reduce global income by only 7.9%, compared to what it would be in the complete absence of global warming.
This sanguine assessment of the costs of climate change contrasts starkly with the non-economic sections of IPCC reports. The recent Global Warming of 1.5°C Report, for example, predicted that 70% of insects and 40–60% of mammals would lose 50% or more of their range at 4.5°C (Warren et al., 2018, p. 792). Yet the economic components of IPCC reports concur with Nordhaus that damages from climate change will be slight: the Executive Summary of Chapter 10 of the 2014 Fifth Assessment, “Key Economic Sectors and Services”, opens with the declaration that:
For most economic sectors, the impact of climate change will be small relative to the impacts of other drivers (medium evidence, high agreement). Changes in population, age, income, technology, relative prices, lifestyle, regulation, governance, and many other aspects of socioeconomic development will have an impact on the supply and demand of economic goods and services that is large relative to the impact of climate change. (Arent et al., 2014a, p. 662)
How can such relatively small estimates of economic damages be reconciled with the large impacts that scientists expect on critical components of the biosphere? The answer is that they can’t, because the economic studies are not based on the scientific assessments of damage from climate change. Instead, the numerical estimates of the impact of climate change on GDP have been made up by economists themselves.
Economic failures of the IPCC process | by Steve Keen | Mediumhttps://profstevekeen.medium.com/economic-failures-of-the-ipcc-process-e1fd6060092e