Is it a result of climate change or something else? Part 2.

Editor's note: This is a continuation of yesterday's post. The writer looks at some of the week's environmental news –  the UN climate chief visited Mongolia, a semiarid country undergoing rapid desertification, and the New Scientist reported that the Fertile Crescent "will disappear this century" – and asks the question: How many of the changes we see happening around us are really attributable to climate change?

He's not denying that human-released greenhouse gases are changing Earth's climate. "At this point, the science points overwhelmingly in that direction," he says. But are there other factors involved in attributing some changes to global warming/climate change? To try to answer that question, he looks at two more incidents:

UN Secretary-General Ban Ki-Moon visited land-locked Mongolia on Monday. The AFP reports:

The theme of Ban's visit to Mongolia is the importance of helping communities adapt to the effects of climate change so they can become more resilient in the face of extreme weather and other environmental problems. ... Mongolia's grassland is rapidly turning into desert, the environmental ministry warned last month. Grassland is thinning in three quarters of the country, while seven percent of the steppe has already become desert.

Mr. Ban said: "You are part of the one-third of the world's population -- 2 billion people -- who are potential victims of desertification."

There's no doubt about that. The question is: Why does desertification occur? Yes, scientists predict that many dry areas will become drier in a warmer world. But in many cases, land-use practices have more to do with desertification than a changing climate.

In Mongolia, for example, overgrazing is a huge problem. By most estimates, the primary driver of desertification is too many animals grazing, not climate change.

In 2001, China's People's Daily reported on a survey by Mongolia's Ministry of Food and Agriculture. One finding: "Mongolia's livestock grew by one third during the period of 1993 and 1997 to reach nearly 33.5 million heads." (It fell to 30.2 million in subsequent bad years.)

It's human population growth that's behind the growth in livestock. The country is still greatly dependent on animal husbandry. In 2001, half the population depended on animals, according to the People's Daily article. That represented 30 percent of the gross domestic product.

Also, Mongolia's population exploded in the 20th century. According to Wikipedia, in 1956, Mongolia had 845,481 people; in 1979, 1,538,980; and in 2007, 2,601,789. In 50 years, the population tripled.

The semiarid landscape may have easily sustained the number of livestock grazing in Genghis Khan's time (the 13th century) and even the number in the 1950s, but now it simply can't. Sure, climate change will likely make things worse. But at least in the short-term, changing land-use practices will go much further than halting CO2 emissions in fighting Mongolia's desertification problem — something that the AFP story does, by the way, allude to.

The same is true in other desertifying areas of the world, such as Africa's Sahel and even the United States' desert Southwest. Human land use is often the critical factor in ecological degradation.

So what about Iraq's water woes? The "fertile crescent" – often called the cradle of civilization – is drying up, says New Scientist. The story's opening paragraph:

Is it the final curtain for the Fertile Crescent? This summer, as Turkish dams reduce the Tigris and Euphrates rivers to a trickle, farmers abandon their desiccated fields across Iraq and Syria, and efforts to revive the Mesopotamian marshes appear to be abandoned, climate modellers are warning that the current drought is likely to become permanent. The Mesopotamian cradle of civilisation seems to be returning to desert.

The immediate impression: Climate change is sending the region into permanent drought. But the article goes on to ascribe many of Iraq's water problems to political jockeying over a fixed water supply. Countries upstream are taking it, essentially. Then it ends:

Drought has helped precipitate the crisis. The most detailed assessment of the Fertile Crescent's future under climate change suggests flow on the Euphrates could fall by 73 per cent. "The ancient Fertile Crescent will disappear in this century," forecasts Akio Kitoh of Japan's Meteorological Research Institute in Tsukuba, Japan. "The process has already begun."

But is climate change really a major factor in the current crisis?

A recent New York Times article lays the blame squarely on upstream countries, as well as Iraq's own water mismanagement:

Officials say nothing will improve if Iraq does not seriously address its own water policies and its history of flawed water management. Leaky canals and wasteful irrigation practices squander the water, and poor drainage leaves fields so salty from evaporated water that women and children dredge huge white mounds from sitting pools of runoff.

There's also the question of land-use practices. Neither article mentions that the Middle East is one of the earliest known areas where humans, through overgrazing livestock and wholesale forest removal, have likely altered climate.

Remember the legendary cedars of Lebanon? Cedar forests once covered swaths of Lebanon, Syria, and beyond. A few cedars now remain in isolated pockets, but, basically, millenniums of timber harvesting have deforested the entire region.

The more an area is denuded, the drier it becomes. Less grows there, there's less foliage, and the ground retains even less moisture — a vicious cycle. Yes, the Middle East was already dry as a region, but human activity likely made it drier long before worries over CO2 emissions arose in the fossil fuel age.

The point is, confirmation biases aside — and we've all got them — you hardly need climate change to create a desert.