Will global warming of a couple of tenths of a degree Celsius bring about certain disaster? That’s what a widely circulated report by Marlow Hood of the French Associated Press suggests about the horrors to come if global warming exceeds 1.5°C.
According to the Climate Research Unit at the University of East Anglia, we’ve already warmed about 0.9° since 1900, although temperatures have been remarkably flat in the first 14 years of this century. A bit less than half of the total warming probably had nothing to do with the combustion of fossil fuels, as it began in 1910, when the increase in atmospheric carbon dioxide was tiny.
Global temperatures are a mere 0.6° away from the dreaded 1.5° threshold. Yet there are reasons to question the concerns voiced in the AFP report; does one seriously believe that if you tack on another 0.6°, all that prosperity, wealth, and health that was accrued since 1900 starts to melt away?
Since then, vibrant economies grew like topsy. Per capita wealth in the U.S. increased by more than a factor of ten, and life expectancy nearly doubled.
Despite the fact that cities naturally warm from the bricks, buildings and pavement retaining heat, and also warm slightly from carbon dioxide increases, heat-related deaths are in decline because people adapt to frequent and repetitive events. And global warming preferentially heats the coldest airmasses, not the hottest ones. It’s noteworthy that winter cold kills 20 times more people than summer heat.
And in spite of rising temperatures, there has been economic development throughout Asia and South Asia in recent decades, with China’s average GDP growth exceeding eight per cent since 2000. In sub-Saharan Africa there have been rapid increases in life expectancy, between 20 to 42% since 2000. It’s unlikely that temperatures 0.6 degrees higher will dramatically reverse that.
Yet the AFP article points to research which says that, despite huge gains in global per capita GDP to date, it will fall globally by 13% if the world meets the 2° ceiling. According to the World Bank, global GDP is currently growing at an impressive 3.7% per year, despite climate change.
The research cited by the AFP is flawed at its core, because it assumes that all the warming since 1900 has been caused by human activity. If the spurt that began in 1910 (and ended in 1945) indeed was due to us, then the atmosphere would be so sensitive to changes in carbon dioxide that it would be hotter than blazes right now.
Global temperatures did spike in 2016, but that was thanks to a big El Niño event, a periodic fluctuation of the tropical Pacific Ocean that releases a lot of heat into the atmosphere. Both satellite-sensed and surface-measured temperatures have since fallen back near to what they were at the end of the 14-year “pause” in warming, prior to the El Niño. Both records show net warming to be about half of what was forecast to be occurring by this time.
The 1.5° goal turns out to be very expensive compared to the two degree limit. Recently Joeri Rogelj of the International Institute for Applied Systems Analysis in Vienna calculated in his econometric model that the cost of limiting warming to the IPCC’s 1.5°C is three times the cost for two degrees Celsius.
And that doesn’t even consider the illogic that literally a few tenths of a degree of additional warming will somehow turn the world around from its prosperous trajectory of the past 120 years.