There are many parts of the earth we cannot live on without artificial support including the oceans, the poles, mountaintops and deserts. In a recent blog I suggested that many parts of the now inhabited earth areas will be made uninhabitable when the wet bulb temperature approaches 35 degrees (see below). The wet bulb temperature is explained here.
In a paper published in 2010 Steven Sherwood of the University of NSW, stated: “prolonged wet-bulb temperatures above 95 degrees (Fahrenheit) would be intolerable after a matter of hours…The wet-bulb limit is basically the point at which one would overheat even if they were naked in the shade, soaking wet and standing in front of a large fan… Although we are very unlikely to reach such temperatures this century, they could happen in the next…Wet-bulb temperature estimates provide upper limits on the ability of people to cool themselves by sweating and otherwise dissipating this heat. In order for the heat dissipation process to work, the surrounding air must be cooler than the skin, which must be cooler than the core body temperature. The cooler skin is then able to absorb excess heat from the core and release it into the environment. If the wet-bulb temperature is warmer than the temperature of the skin, metabolic heat cannot be released and potentially dangerous overheating can ensue depending on the magnitude and duration of the heat stress.”
Sherwood’s reference that we were unlikely to reach wet bulb temperatures until next century may have been referring to large areas being made uninhabitable by this process. But in May 2016 Robert Scribbler reported that in places near the India Pakistan border the dry bulb temperatures topped 50 degrees and nearer the coast approached the crucial wet bulb temperature of 35 degrees. These temperatures caused a substantial number of heat stress casualties and fatalities across northern India. Pakistan had similar high wet bulb temperatures in 2015 with similar outcomes.
Approximately 40% of earth’s population – more than 3 billion people – live in the tropics. Likewise about one third of Australia lies within this highly vulnerable area. With each degree climate change warms the earth there is 7% more moisture in the atmosphere. Those areas where highest wet bulb temps have so far been recorded are in the tropics or adjacent to it. A worst-case scenario map (above) by Huber accompanied the Sherwood article.
There is a problem in examining this aspect of warming in isolation and not allowing for all the other climate induced changes happening simultaneously including sea level rise, heatwaves, population movements, crop failures, droughts and many other, some as yet unrecognised, consequences. In the worst-case scenario the Australian continent, including Gippsland, becomes uninhabitable. Meanwhile there is currently a push for a new coal fired power generator in the Valley. That is a sign of madness.