40 percent poorer or 370 percent richer?
How framing matters
“Average person will be 40% poorer if world warms by 4C, new research shows.”
This is reported by The Guardian and many other media outlets. It is based on the article Reconsidering the macroeconomic damage of severe warming published in Environmental Research Letters. The sentence in the abstract of the article that is the basis for this statement is: ” Damage to world GDP in 2100 under SSP5-8.5, averaged across both econometric models and climate models increases from ∼11% under models without global weather to ∼40% if global weather is included.”
But neither the abstract in the research articles, the article by the main author in The Conversation, nor the media reports explain that the “damage” to the GDP is theoretically calculated compared with the calculated GDP for the IPCC:s SSP1-2.6 scenario by 2100. This is expressed in the articles main text: “Forecasted damage to global GDP per capita from severe climate change is then calculated as the percentage deviation between the forecasts of world GDP under SSP5-8.5 against a baseline of forecasts under SSP1-2.6.”
In the SSP1-2.6 average GDP per capita is projected to increase from 13 000 US dollars to 81 000 dollars in real terms (measured in fixed dollar rate), that is an increase of 620 percent (see chart). The 40% reduction in GDP thus corresponds to an increase of 620%*60% = 372 %!
I would say that the sensational aspect of this research is that climate change would still allow a tremendous economic growth, which actually could be construed as an argument for why we shouldn’t worry about climate change at al. How would a headline stating: ”Average person will be 370 perdent richer if world warms by 4C, new research shows” be received?
The 40 percent reduction of the GDP is actually a 370 percent increase.
I am concerned about global warming, but I find it highly problematic when research is giving such a distorted view of the effects of global warming.
I also find it highly problematic when researchers are writing their abstracts, press releases or articles in a way to either catch the public interest (klick-baits) or twist their results into something else than they actually show. In this particular case the lead author writes in The Conversation, that this level of harm to the global economy “could devastate livelihoods in large parts of the world.” I am sure that climate change will have devastating effects, but it is hard to state that a 370 percent higher income compared with today will be devastating compared to a 620 percent higher income.
I also find it highly problematic that media outlets don’t read scientific articles with a critical eye, especially when the same media is full of fact-checks and statements about disinformation. It seems to me that being sceptical and checking the sources only apply when there is news contradicting the prevailing narrative.
How credible are the projections?
In the end, the projections in most the IPCC scenarios when it comes to GDP is totally off the mark. The idea that global GDP could grow by 620 percent in the remaining 75 years up to 2100, is just wishful thinking with no support in reality. And the SSP5 scenario projects a 1000 percent increase. The climate and the economy are extremely complex systems with numerous feedback loop within themselves and between them as well as to other systems in the biosphere. Both are susceptible to tipping points and other unpredictable developments. To combine them in projections 75 years ahead is guesswork, guesswork based on very advanced models, but still guesswork.
But despite all this advanced modelling, among all the IPCC scenarios, there is not one single scenario projection for no growth or de-growth, something that I believe seriously undermines the credibility of the IPCC. Even if they think it is not so likely, as scenarios are there to demonstrate possible outcomes, it would have been appropriate to have no-growth and a de-growth scenario as well.
I find it amazing that so few researchers are aware of the fact that all economic growth is depending on increased energy use. And that 80% of the energy comes from fossil. The dream of phasing out fossil for "rebuildable" energy production is not possible at large scale. So we are struck with what is remaing of fossil energy until it becomes too expensive to extract.
This will happen gradually during the coming decades and we will have to revert back to more physical work again at a lower living standard. Eternal growth is about to disappear long before 2100, probably in a decade or two. This also means that the climate models based on that growth is faulty.
Even without all the recent politicization and polarization, research has been in a crisis for a while. Publish or perish, chasing grants that practically define the results, all the recent concern over the replication crisis confirms that money is driving the bus, not rational inquiry. We are in a fog of uncertainty, and I simply don't know what to believe anymore. Thanks for tagging one example.