This Labor Day weekend saw a batch of headlines like, “More than 230 journals warn 1.5°C of global warming could be 'catastrophic' for health,” (https://www.wsj.com/articles/action-on-climate-change-is-urged-by-medical-journals-in-unprecedented-plea-11630886402). This kind of extreme overstatement has become so routine that none of the news outlets I read expressed any kind of surprise or skepticism.
To be clear, I’m not denying that warming is a serious long-term problem, with catastrophic scenarios possible. But the idea that 1.5°C is some kind of threshold that will predictably lead to large increases in death rates is hysterical overreaction, unsupported by science.
We’ve already seen the effects of getting 91% of the way to 1.5°C (we saw a global warming of 1.37°C in February 2016) and the health damage is yet to be found in death rates. The chart below shows temperatures steadily increasing since 1960, while crude death rates fell even more steadily. I understand there’s a difference between 1.37°C for a month and 1.5°C for decades—some damage takes years to show up—but shouldn’t 60 years of steadily increasing temperatures led to some increase in death rates if 1.5°C is a massive health disaster?
I suppose it’s logically possible that the death rate would have declined faster without the temperature increase, but then it’s obvious that economic growth and technological innovation are far more important to death rates than climate, so we shouldn’t risk the economy and innovation to improve the climate.
If temperature is so dangerous, shouldn’t we see higher death rates in warm places than cold places? The chart below shows the opposite, death rates declining with temperature by country. Absolute mean global temperature is probably around 15°C, so if we go up from, say, 15°C to 16.5°C there isn’t any huge jump death rates. Granted there are problems with the data—like countries reporting zero death rate—but the trend is undeniable. We also know there are more deaths in cold months than warm months in the same places.
Once again, none of this means rising temperatures are not a problem, just that they’re not a fall-off-a-cliff in panic problem. We have ample data about the effect of higher temperatures, both over time and from place-to-place. There’s no dramatic shift, and warmer in general in better than colder. Not just longer lives but more prosperity. There aren’t more natural disasters in warm places than cold ones, nor more wars, famines or pandemics.
The problems with rising temperature and long-term, uncertain and subtle. They don’t show up in a month, or maybe not even in 60 years. Things can adapt for decades without major effects, then at some combination of stress change abruptly. There are many possible tipping points in climate and the environment and biosphere in general. Some of them might be catastrophic to humans.
That means the solutions should be long-term, humble and careful. We have no policy options to guarantee global warming stays below 1.5°C—the only chance would be to embark on massive untested geoengineering with risks far greater than doing nothing. Stoking panic about 1.5°C would be foolish even if there were evidence of a cliff at that level. You plan for the horizons you can affect, not for the horizons you fear.
Another lesson is that economic growth and technological progress have been far more important to human health over the last 60 years than climate. Any climate solution that intends a net improvement in human health has to balance warming with innovation and growth. Finally, while it’s not obvious from the data shown here, significant global emission reductions absolutely require cooperation from China, India and other nations. Solutions that bypass the need for international cooperation and goodwill cannot succeed, and world peace is not a sprint goal to be accomplished from panic.