Warmth will worsen wet and dry extremes – Climate News

GR: This warning is worth repeating. It needs to reach the ears of the climate-change deniers whose willful ignorance is endangering all of us and all the creatures sharing this ride with us. Storms, floods, and droughts will get worse.

Cloudburst, North Vancouver: Wet or dry, extremes will become more intense. Image: Terence Thomas via Wikimedia Commons

“Wet and dry extremes across the world will become more marked as the planet heats up, evidence from past climates shows.”

“Two US scientists have once again confirmed one of the oldest predictions of climate change: that those regions already wet will become wetter, while the arid zones will become drier.

“This time the reasoning comes not just from computer models of future climate, but also from the evidence of the past.

“Because the northern hemisphere will warm faster than the southern, the temperature difference will drive the planet’s rainbelts northwards, at least during the winter months. The tropics will become wetter, while the subtropics and the mid-latitudes will become drier, and this will be most noticeable in June, July and August.

“The predictions – made in the journal Science Advances – come from two researchers. Aaron Putnam is a glaciologist who studies ancient climates at the University of Maine. Wallace Broecker is an oceanographer at the Lamont-Doherty Earth Observatory of Columbia University, and one of the pioneers of climate research.” –Tim Radford (Learn more: Warmth will worsen wet and dry extremes – Climate News NetworkClimate News Network.)

Desertification and China’s Great Green Wall

“Unlike the Great Wall of China, a 5,000-mile fortification dating back to the 7th century BC that separates northern China from the Mongolian steppe, the Great Green Wall of China-otherwise known as the Three-North Shelter Forest Program-is the biggest tree planting project on the planet. Its goal is to create a 2,800-mile long green belt to hold back the quickly expanding Gobi Desert and sequester millions of tons of carbon dioxide in the process. If all goes according to plan, the completion of the Green Wall by 2050 will increase forest cover across China from five to 15 percent overall.

“The Chinese government first conceived of the Green Wall project in the late 1970s to combat desertification along the country’s vast northwest rim. Soon thereafter, China’s top legislative body passed a resolution requiring every citizen over the age of 11 to plant at least three Poplar, Eucalyptus, Larch and other saplings every year to reinforce official reforestation efforts.

“But despite progress-according to the United Nations’ most recent Global Forest Resources Assessment, China increased its overall forest cover by 11,500 square miles (an area the size of Massachusetts) between 2000 and 2010, with ordinary citizens alone planting upwards of 60 billion trees-the situation is only getting worse. Analysts think China loses just as many square miles of grasslands and farms to desertification every year, so reforestation has proven to be an uphill battle. The encroaching Gobi has swallowed up entire villages and small cities and continues to cause air pollution problems in Beijing and elsewhere while racking up some $50 billion a year in economic losses. And tens of millions of environmental refugees are looking for new homes in other parts of China and beyond in what makes America’s Dust Bowl of the 1930s look trivial in comparison.”  Source: www.healthnewsdigest.com

GR:  A little reading in this article and its references quickly reveals that despite China’s massive commitment to reforestation, desertification is increasing.  Part of the problem is that the land-use practices that led to vegetation loss and soil instability are continuing.  Another part of the problem is that Chinese planners are making the same mistakes made in the U. S. and in other arid regions where managers used nonnative plants to replace depleted natives.

Many of you will be nodding and thinking that whenever land-use managers focus on Human benefits, they lose sight of the need for complete ecosystem health. They focus on potential benefits from foreign species that appear to be suited to growth on degraded lands.  Their goal is to continue profitable logging, livestock grazing, and water diversion.  Therefore, the desert grows.


Thanks to Professor Willem Van Cotthem for his efforts to provide a single Internet source for work on desertification (https://desertification.wordpress.com).

Desertification and Biodiversity

The link between land degradation and desertification has been made abundantly clear in studies conducted in Africa and Australia. A loss of natural vegetation, a loss in soil organic matter and a loss of soil stability contribute greatly to the process. These processes are often interlinked. Vegetation encourages soil stability by providing cover, the binding action of roots, providing root exudates and by the contribution of its biomass to the soil. A loss of vegetation results in a corresponding loss of soil organic matter and stability.

Soil organic matter and soil stability are often linked. A soil that becomes depauperate in its content of organic matter looses the glue that holds soil particles together and becomes easily erodible. The more a soil erodes the more difficult it becomes for the soil microorganisms to glue the particles together. The process is analogous to a spider’s web in the wind. A whole web can withstand the pressure. If one of the threads that anchor it is broken the spider can repair it, but if the rate of damage is slowly increased, there will come a time when the spider cannot repair the damage and the web will be destroyed by the wind.

Every environment has a threshold beyond which damage cannot be repaired by the natural system. In arid and semi arid environments this threshold is very low.”  –Source: groundviews.org

GR:  Naturalists have been concerned about desertification for more than a century.  Though the term has not been in the news very much in recent years, the process has continued wherever people have conducted marginal farming, excessive livestock grazing, watershed deforestation, and other improper land-use practices.  Recently, the term has been showing up more often, and I think we will soon begin to see it regularly seated beside biodiversity as one of the great concerns of this century.

Soil Isn’t Sexy

“Soil is the earth’s fragile skin that anchors all life on Earth. It is comprised of countless species that create a dynamic and complex ecosystem and is among the most precious resources to humans…Half of the topsoil on the planet has been lost in the last 150 years.” WWF

“Desertification is a phenomenon that ranks among the greatest environmental challenges of our time, unfortunately most people haven’t heard of it or simply don’t understand it.

“Desertification and land degradation is a global issue with desertification already affecting one quarter of the total land surface of the globe today

“Today the pace of arable land degradation is estimated at 30 to 35 times the historical rate. Land degradation is costing US$490 billion per annum and desertification is degrading more than 12m hectares of arable land every year – the equivalent of losing the total arable area of France every 18 months.

“Every morsel of food we eat . . . our clothes . . . our houses and most everything that’s in them…each scrap of paper, from birth certificates to books to dollars…our fuel…even the very oxygen we breath: All of it comes from plants, trees…and topsoil.”

Source: www.marketoracle.co.uk

GR:  Soil erosion is the least-mentioned major crisis of all.  When do all humans begin to mourn the wealth of the planet Earth that we have squandered?