Recent temperature extremes support global drying

12/16/14

The Oregonian prints summaries of Earthweek every Friday.  Last week, the headline was "Quickening Extremes:" "The number of outbreaks of extreme heat and cold around the world during the past three decades increased more rapidly than the rate of global warming, which scientists say is fueling the trend."

One suspects that the scientists involved are all climate scientists who have long bought into trace-gas warming alarmism.  Weathermen and physicists know that dryness brings on extremes of temperature, as Arizona's desert illustrates: cold nights and hot days in summer; colder nights and days in winter; and cooler days and warmer nights during the humid summer monsoon season.

One cannot find any article on Oregonlive.com unless it is written by their writer.  So I looked it up on Earthweek: http://www.earthweek.com/2014/ew141212/ew141212a.html.  It has a lot more information than the Oregonian brief.  But their page does not allow one to copy and paste.

It continues, "Researchers at the UK's University of East Anglia looked at temperature records from 1883 to 2013 before coming to the conclusion.

"They found that the occurrence of unusually cold periods had been increasing at a faster rate than heat waves until 30 years ago."

"But the trend reversed in 1983, when extreme heat events became more frequent."

"Temperatures were also found to be more variable in the Northern Hemisphere than the Southern Hemisphere, mainly because there is less landmass south of the Equator to make weather systems more complex."

This fits with the increase in modern irrigation from 1883 to 1983, which was about the time the water-saving no-lawn movement began, followed by water price hikes in cities to save water, regardless of local supplies and conditions.  In Grants Pass, overpricing has been too successful, with seemingly half the town going dry in summer.  

I was part of the anti-lawn movement until a few years ago, simply because I hate mowing.  But as a professional gardener for the last 14 years, I have come to realize that replacing lawn with ground covers, shrubs, flowers, especially edibles does not save any water over lawn, as most plants and all vegetables need an inch of water per week, just like lawn.  

Lawns and hedges are also easier for most people to maintain, as it takes little knowledge to water deep, give everything a haircut, and to weed out everything but lawn grasses.  But with high water prices, many have simply stopped watering and weeding.  They can't afford to water, and no one likes to maintain ugly, so they ignore the yard and its weeds and play indoors.  

Since they can't garden without water, the poor are not learning how to garden, and paid gardeners are scarce.  Our Food Bank rents farmland from the City to supply the poor, and gets middle class volunteers to weed it.  The poor used to supply the Food Bank with excess vegetables and enter their best produce in the Fair.  Produce entries in the Fair are pitifully few these days, spread out thinly through a huge building.

A bit over a year ago, after reading this article in Science News on irrigation from Central California farms increasing monsoon rains in the Four Corners area and water in the Colorado River, I did a study of weather in Grants Pass from 1983 to 2013, and wrote this blog post.  

It shows that midsummer monthly high temps dropped slightly from 1993 to 2003, and then rose a lot from 2003-2013.  In the same two decades, midsummer rainfall dropped by 0.9 inches per decade, and July and August high rainfall events were lower than those in June and September.  In the first decade, when we were nearly all watering, July and August rainstorms were bigger than in June and September, which fit with my memories of frequent wet summer thunderstorms when I lived here between 1985 and 1987.  

When this area was first settled by white people, it was called the Agate Desert.  It takes a lot of irrigation to grow food here.

Sprinkler irrigation cools, humidifies, and reduces weather extremes.  Less irrigation can only do the reverse, especially with high temperatures.  Drip contributes some humidity through transpiration from plants, but not like throwing water in the air and all over the plants.  The effects are seen the most in the interior of the continents, far from the moderating humidity of the ocean.

 



 at the U.K.’s University of East Anglia looked at temperature records from 1881 to 2013 before coming to the conclusion.

They found that the occurrence of unusually cold periods had been increasing at a faster rate than heat waves until 30 years ago.

But the trend reversed beginning in 1983, with extreme heat events becoming more frequent.hers at the U.K.’s University of East Anglia looked at temperature records from 1881 to 2013 before coming to the conclusion.

They found that the occurrence of unusually cold periods had been increasing at a faster rate than heat waves until 30 years ago.

But the trend reversed beginning in 1983, with extreme heat events becoming more frequent.