September 11, 2024
“Shocking data”: according to the Corriere della Sera, the main Italian newspaper, “the cold has disappeared” as a result of climate change and last year, the Guardian tells us, heatwaves killed nearly 50,000 people in Europe.
Yet, as it often happens when it comes to dealing with issues related to climate change, reality is much more complex and does not lend itself to simplifications. Two recent examples are the sinking of atolls and desertification.
In November 2021, Simon Kofe, foreign minister of Tuvalu (Polynesia), spoke remotely at the climate conference in Glasgow with his legs mostly in the water.
Scientists and journalists insistently tell us that the increase in water volume and the melting of glaciers are provoking a rise in sea levels. Not surprisingly, the 1.5°C target at the core of the 2015 Paris Agreement was established also under pressure by the Alliance of Small Island States worried for their own quick sinking.
Yet, this is only half of the story. For many years, scientist have observed that atolls can naturally adapt to a rising sea levels by accreting sediments from the surrounding coral reefs. The press has not written much about this phenomenon. The New York Times considered the news fit to print only last June, after it interviewed the author of a 2008 paper stating that 89% of Pacific and Indian islands are either stable or increased in area while only 11% contracted. The researcher added: “I am confident that there’ll be islands in the Maldives 50 or 100 years from now. They are not going to look like these islands; they’re going to be different. But there will be land here”.
This does not mean that there is nothing to worry about. Sea level will continue to rise for many centuries due to our past and future emissions. Nevertheless, the reality is far less dramatic than usually perceived.
Another pillar of the climate change story telling is the spreading of desertification around the world due to higher temperatures and lower precipitations. Overall, the opposite is true. Between 1981 and 2020, the rise of CO2 in the atmosphere increased global photosynthesis by around 13.5% per year. As a result, the net effect is that “most of the global drylands are projected to see an increase in vegetation productivity due to climate change through 2050”.
Now, back to temperatures: today, the world is about 1°C warmer than fifty years ago and Europe is 2°C hotter.
The traditional interpretation of this trend is almost one-sided, though. As mentioned before, we often read about the excess mortality during the heatwaves. Yet, probably very few people know that in the world ten times as many people die from cold temperatures than from the heat. This happens not only in the coldest areas, but also in North and Sub-Saharan Africa.
In fact, ceteris paribus, warming causes an increase of heat and a decrease of cold-related mortality. The net effect varies from place to place, but it has been estimated that colder countries will benefit until at least 2050 while those near the equator will be harmed.
The above estimates do not take into account spontaneous adaptation. We know that this phenomenon can be significant. In the United States, for example, the mortality impact of days with mean temperature exceeding 80°F (26.6C) declined by 75 percent over the course of the twentieth-century. Almost the entire drop occurred after 1960, and the diffusion of residential air conditioning explains essentially the entire change.
In 2018, the share of households with air conditioning in China was already 60%. Growth is the key: the correlation between AC and income is very strong, starting from $10,000. According to the International Energy Agency, the number of air conditioning units will rise from 2 billion to 5.6 billion by 2050. In this scenario, the impact of warming on mortality will be significantly lower.
To sum up, science tells us that climate change emerges as a real and growing phenomenon, but not as an existential threat that justifies drastic cuts in CO2 emissions whatever their cost.
Lower-carbon energy means also more expensive energy, otherwise consumers would freely choose it and no obligation, subsidy or other form of regulation would be necessary to increase its adoption.
It also implies greater risks for human lives. The Economist estimated that between November 2022 and February 2023, the rise of the price of electricity led to 68,000 more deaths from cold in the 28 European countries investigated.
More generally, economic growth makes us much less vulnerable both in terms of numbers of victims and economic costs. The average economic loss from disaster is equal to about 1% of GDP in lower middle-income countries compared to 0.1% in high income countries.
In a sentence, grand climate policies may be worse than doing nothing.