Further Desertification results in extinction – causes loss of food, exacerbation of climate change and bio-d, makes areas more conflict-prone, and affects the most marginalized populations first

Desertification and land degradation is "the greatest environmental challenge of our time" and "a threat to global wellbeing", according to the UN's top drylands official, who says people must be paid via global carbon markets for preserving the soil. Luc Gnacadja, executive secretary of UN's Convention to Combat Desertification (UNCCD), will today [Monday] launch the UN decade for the fight against desertification in London. "The top 20cm of soil is all that stands between us and extinction," he told the Guardian. Land conflicts in Somalia, dust storms in Asia and the food price crises of recent years all stem from the degradation of land, he said, due to overuse by humans and the impacts of global warming. Since the early 1980s, a quarter of the planet's land has been despoiled and 1% a year continues to be lost. The better known issues of climate change and loss of biodiversity are both rooted in the global loss of fertile soil, said Gnacadja, as the soil harbours a huge stock of carbon and the health of creatures living in the soil underpins global food production and forest growth. The reason desertification has not been a priority is because 90% of the 2.1 billion people who live in drylands live in developing countries, he said. "Even in their own countries, they are the poorest among the poor and live in remote areas," said Gnacadja. "The world is driven by city dwellers: political leaders are setting agendas to satisfy people who live in the cities, we therefore tend to perceive soil as just dust, or mud, or a dumping place. But if we don't preserve that first 20cm of soil, where will we get our food and water from?" Half the world's livestock are raised on drylands and a third of crops, especially wheat. The impacts of climate change – rising temperatures and more erratic rainfall – are here already from Latin America to the Sahel, said Gnacadja. Adding to the pressure on land is rising global population, which is expected to pass the 7 billion mark next year and reach 9 billion by 2050. As well as the consequences for food and water, violent conflicts and migration will also increase, he said, affecting those living outside drylands. "Increased aridity is making the drylands the most conflict prone region of the world," he said. "If you really want to look at the root causes of the conflicts in Somalia and Darfur, and drylands of Asia, you will understand that people in their quest to have access to productive land and water for life, they end up in conflict." He also cited nothern Nigeria, where increased aridity means lack of fodder is driving herders south into the areas farmed for corn. "Conflict is almost inevitable." Desertification and rising aridity were the ultimate cause of the food price crisis of 2007-8, Gnacadja said, as it began with a drought in Australia. This year's price spike started with a drought in Russia. Another example of desertification's impact was the loss of land bordering the Gobi desert leading to record dust storms that damage the health of people in Seoul in South Korea, thousands of kilometres away.

Monarch butterflies (Danaus plexippus) are a long-migratory species of butterfly that span much of North America and use the milkweed (Asclepius spp.) as their mating habitat. Although not officially listed as threatened or endangered, monarch butterflies have experienced massive decline in their population. Since the 1980s there has been more than a 80% decrease in the eastern migration and about 99.4% decrease in their western migration. That is roughly a decrease from 4.5 million to approximately 28,000 today. Later this year the U.S. Fish and Wildlife Service was to have voted on whether the monarch butterfly should be protected under the Endangered Species Act; given recent moves to change the way this Act is applied, it is unclear that the monarch’s threatened habitats would be adequately protected to ensure the survival of the species.