Friday, August 03, 2018

The steamy details!

In a recent email, a cousin referred to Chennai as "the hottest place on earth!"  I suspect that there was not much snark in that comment :(

Chennai, like seemingly all the places on this planet, appears to be getting hotter and hotter every year.  More than that heat itself, the humidity of this coastal city can suck the energy in a matter of minutes.

First, let's make sure we understand sweating: "Humans shed heat by sweating and letting the evaporating moisture carry excess heat away."  We cool down thanks to the stinky sweat.  If sweat smelled like perfume, well, I will be a walking cologne factory!

When you have a whole bunch of sweaty people in the tropics, hey, this is a big reason why women wear fragrant flowers on their hair and bodies, and men apply sandal paste on themselves.  We humans stink otherwise!

Climate change is not merely about the temperature.  It will also affect the humidity.  What happens then?
“It’s not the heat that kills you. It’s the humidity.” As climate change progresses, this is likely to become gruesomely true, according to a new study published Friday in Environmental Research Letters. Climate change–induced increases in humidity could actually exacerbate the effects of heat to the point of making certain places in the world uninhabitable later this century.
Why?  Because it alters the mechanics of the sweat-cooling process:
when humidity is too high, your sweat doesn’t evaporate as fast, because there’s already tons of moisture in the air. The cooling process is stymied, and your body can’t lower its temperature. Every part of you starts to feel tired, and if you can’t get inside to climate-controlled conditions, heat exhaustion or a heat stroke could take effect.
This is when you begin to think that maybe a place like Las Vegas is better because it is only dry heat. Think again!

There are no signs of any reversal of the hockey-stick trendline.  Which means:
If global greenhouse gas emissions continue at their current pace, they say, heat and humidity levels could become unbearable, especially for the poor.
And there is the heat-island effect.  The rich can hide only a little bit in air-conditioned cocoons.  They, too, will be screwed.

if current warming trends continued, by the end of the century, wet bulb temperatures — a measure of heat and humidity that can indicate the point when the body can no longer cool itself — would be so high that people directly exposed for six hours or more would not survive.
So, the wet bulb temperature. The heat index that factors in humidity also.  Consider Chennai's 90 degree heat (we refuse to use Celsius, dammit!!!) with 50% humidity.  That is the equivalent of 95 degrees.

Now, think of a 95 degree day in Chennai with 55% humidity.  It is 109 degrees!

You think trump and the Republicans care?


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