Land degradation and desertification fundamentally undermine the carrying capacity of our planet. Across the world, land degradation is forcing people to flee their homes and homelands. Already, more than 500 million hectares of farmland – an area more than half the size of China – have been completely abandoned due to drought, desertification and land mismanagement.

“Over the next few decades, worldwide, close to 135 million people are at risk of being permanently displaced by desertification and land degradation. If they don’t migrate, the young and unemployed are also at more risk of falling victim to extremist groups that exploit and recruit the disillusioned and vulnerable.”

So says Monique Barbut, Executive Secretary of the United Nations Convention To Combat Desertification, in a message to mark the World Day To Combat Desertification on 17 June. This year the Convention is calling for a focus on making the land and life in rural communities viable for young people, under the theme: “Our land. Our home. Our future.”

Land degradation is usually caused by intensive agriculture or the activities of often impoverished people who slash and burn the land before moving on to do the same elsewhere. It can be aggravated by climate change and poor governance.

But, if properly managed, the land can provide not just enough to get by, but a place where individuals and communities can thrive.

“Let’s give young, rural populations better choices and options,” says Barbut. “We need policies that enable young people to own and rehabilitate degraded land… Let us give young people the chance to bring that natural capital back to life and into production.”

Stories of migration caused by environmental degradation pepper human history. The Dust Bowl exodus from the American Prairies in the 1930s, for example, was a combination of severe drought and poor land use. It led to massive soil erosion and the United States’ biggest internal migration.

More recently, the 2006-2009 drought in Syria was the worst the country has experienced in modern times. Exacerbated by climate change, the drought led to significant displacement of people from rural to urban areas. This may have contributed to the outbreak of civil war in 2011.

“Land degradation affects where and how people live,” says UN Environment Executive Director Erik Solheim. “It drives human displacement by threatening lives over the short term and making people’s livelihoods untenable over the long term, particularly the poorest and most vulnerable.”

Other environmental drivers of displacement are natural disasters, sea level rise, resource conflicts and land grabbing, industrial accidents, and large infrastructure projects such as hydroelectric dams.

Environmental migration is a warning sign that we are failing to manage our environment sustainably.

“When you look at the root causes of displacement, environmental change or degradation is often a part of the story, so better environmental management should be part of the solution,” says Oli Brown, a disasters and conflicts expert with UN Environment.

UN Environment is working with other UN agencies on the 2018 Global Compact on Safe, Orderly and Regular Migration. The Compact is supposed to develop a new international framework for the management and protection of migrants and displaced people. If this happens — a big “if” — this will be a watershed moment in the international management of migration.

[This article originally appeared on unep.org]