Just too darn hot?
If global warming continues unabated due to business-as-usual emissions of greenhouse gases, disturbing new research suggests, human tolerance could be pushed to the limits in the very near future. Humans have lived in significantly colder climates before now, they haven't lived in much warmer ones. There are physical limits to how much our bodies can adjust to higher temperatures. It is entirely possible that many parts of the world could simply too hot for humans.
We do know that earth is warming at a swifter pace than even the gloomiest scenarios predicted just a few short years ago, the latest research shows, and the extreme weather events that have crippled numerous regions across the world in the past year underscore this alarming trend. Now that climate change has become, in the words of Thomas Friedman, "blindingly obvious" to most people, even Mitt Romney, politicians and corporations are now pushing the comforting notion that we can somehow adapt to these changes, and acclimate to higher temps, according to the U.S. Chamber of Commerce, through "a range of behavioral, physiological and technological adaptations."
But new research suggests that may be impossible and that incremental steps, like painting thousands of roofs white to reflect the sun in order to mitigate the urban heat island effect in cities like Chicago and New York, may be the equivalent of moving the deck chairs on the Titanic. In the not too distant future, temperatures could rise so high so fast, according to a disturbing study by scientists in Australia and here in the United States, that adaptation is impossible and many regions of the Earth will become uninhabitable.
Sound farfetched? It's not so outlandish when you look at what's been happening in the past year. Bear in mind that the freak weather patterns that have unleashed deadly tornadoes across the Midwest and in Massachusetts, severe droughts in the Southwest, and massive flooding along the Mississippi, and in Australia, China and Pakistan, are the result of a mere two degrees Fahrenheit rise in temperature in the last century. And we ain't seen nothing yet, scientists grimly tell us: even more extreme weather is on the horizon.
Because of the CO2 that has already been emitted, we're on track for an additional five degrees of warming in the next few decades, even if we stop dumping carbon in the atmosphere tomorrow, which isn't happening. As a consequence, the long, gradual, linear warming-which would give us ample time to adapt-isn't the way it will play out, the latest models tell us. Change will be quick, violent and abrupt.
At what point will the world become just too darn hot? All humans, no matter where they live, maintain a core body temperature of about 98.6 degrees. This warmth is maintained by our metabolism. But it is crucial that our bodies be able to get rid of this heat without body temperatures rising too high. An elevated core body temperature causes a variety of acute and chronic health problems. By the time the core body temperature exceeds 104 degrees, organ damage occurs. An additional 2 degree rise in core body temperatures can results in death.
If ambient temperature and humidity become high enough, heat removal becomes impossible because heat must flow into, rather than out of, the body. At a certain point, it creates intolerable outdoor conditions, even in the shade in some areas. In the absence of strong measures to reduce greenhouse gas emissions, a temperature increase of ten degrees could occur within the lifetimes of babies born today, making much of the planet too darn hot.
While many Americans will be able to retreat to the comfort of their air conditioned homes-if they don't have power outages from grid failures due to overwhelming demand-people in developing countries who can't afford costly electrical power could perish by the thousands. The Amazon and parts of India would be first, with northern Australia and other regions with very humid summers not too far behind. Not a pretty picture and one more reason to push for reducing carbon emissions.