Wednesday, September 12, 2012

Nature's Version of Waterboarding

Think of it as the difference between a refreshing drink of water and undergoing waterboarding.   We used to expect the former from nature but now, all too often, it's the latter.

Las Vegas is an object lesson.   The desert city is now forced to drain its essential freshwater from a distant corner of the state via a canal system.   Until nature shows up but then it's often in the form of deluge triggering flash floods.

The city, that averages 4.5 inches of rain annually, got hit with a 1.75 inch downpour that left parts of the city flooded, like this parking lot at the University of Nevada, Las Vegas:


The floods have hit various spots throughout the American southwest.   Yet this sort of urban flooding is now established world wide.   Many municipal storm sewer systems are not designed to handle the sort of rainfall patterns they're now experiencing.  Runoff becomes concentrated and backs up, resulting in heavy flooding.   From Britain to the Philippines to China to the United States and elsewhere, heavy flooding is becoming commonplace.

Many of these areas are also beset by sustained drought that can harden the ground and make it impervious.   Then, when floodwaters arrive, they don't seep into the ground but simply run off into what the Mexicans call arroyos, normally empty streambeds carved out by centuries of flash flooding.

Today's floods, just like today's droughts, evidence our broken hydrological cycle.   Surface temperatures warm, increasing evaporation.   Atmospheric temperatures warm, increasing volumes of water vapour, itself a powerful greenhouse gas.   Warmer, wetter conditions create more atmospheric energy that results in erratic precipitation patterns and severe storm events of increasing frequency and intensity.   Some regions get hit by torrential rains, others are bypassed and experience drought.

This is occuring this year in most of the world's greatest grain producing countries - the United States, Australia and Russia in particular.   Food prices globally are already spiking.  A continuation of this threat will destabilize already wobbly countries around the world.

Predictable, reliable and moderate rainfall has been a vital part of mankind's introduction of agriculture that, in turn, facilitated the rise of civilization.   With but a few exceptions, farmers could count on receiving the right amounts of rainfall at the right times throughout the planting/growing/harvest cycle.   Too much rain or too little rain at any stage and the crop might fail.

Despite demographic predictions that the world population will reach 9-billion by 2050, perhaps 15-billion by 2100, the hydrological cycle problem could make those projections unrealistic.  At 7-billion, mankind's ecological footprint is already placing us in a severe "overshoot" deficit.   World Overshoot Day this year fell on August 22nd, several weeks earlier than just a few years ago.  In effect, mankind now uses a full year's worth of the Earth's renewable resources before the end of August, leaving us to "eat our seed corn" for the balance of the year.   This deficit is only going to be worsened by disruptions in agricultural production from droughts and floods.

We are being overtaken by events.   The theme of Gwynne Dyer's latest column could be "nobody saw it coming."  But it's here and we're going to have to find ways to live with it - better systems to collect and hold rainwater, curbs to water usage and wastage, improved agriculture and food distribution, for starters.   We're also going to have to realistically price carbon to whatever extent necessary to decarbonize our economies and our societies.  Above all else we'll need to develop technologies to strip atmospheric carbon in massive amounts.

For mankind this is likely the fight of our lives.   Yet that is still a far cry better than having to fight for our lives.

5 comments:

Anonymous said...

'severe overshoot' link returns a 404

The Mound of Sound said...

Thanks, anon, link fixed.

Beijing York said...

On the CBC Radio 6:00 pm news about the flash floods in central NS, an ex-member of the Harper Regime axed Committee on the Economy and Environment was interviewed. He said they released a report last year that outlined Canada's need to upgrade infrastructure that was not built to withstand the new normal in extreme weather patterns. My guess is that that report went straight to the garbage when they closed the outfit down.

The Mound of Sound said...

Hi, BY. For all the talk about stimulus spending what better place for that but to upgrade infrastructure as required by climate change impacts? Yet to do that would be an admission of the problem that Harper can't let cross his lips. Acting in a timely and effective fashion on adaptation would run afoul of his dreams of petro-superpowerdom.

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