BRUSSELS: Europe's leaders are being warned to prepare for big new flows of migration by 2020 as climate change puts strains on food and water supplies, provokes natural disasters and undermines political stability in poorer, neighboring countries.

A report prepared for the European Union heads of government, who will meet Thursday in Brussels, said that the rest of the world could not insulate itself from the impact of changes that could overwhelm regions that already suffer from poverty and conflict.

So serious are the threats that the multilateral system of global governance could be at risk if the international community failed to address them, the document said.

Because of its proximity to North Africa and the Middle East, both of which are vulnerable to the pressures caused by climate change, "migratory pressure at the EU's borders and political instability and conflict could increase in the future," the document said.

In North Africa and the sub-Sahara, drought and overfarming could lead to a loss of 75 percent of arable land. The Nile Delta could be threatened by both rising sea levels and salinization of agricultural land. Between 12 and 15 percent of arable land could be lost to rising seas in this century with five million people affected by 2050. Meanwhile, both the Horn of Africa and southern Africa are vulnerable to reduced rainfall and higher temperatures.

"Migration in this region, but also migration from other regions through northern Africa to reach Europe, is likely to intensify," the report said.

The document, which will be presented by the EU's foreign policy chief, Javier Solana, listed a series of phenomena that could destabilize poor nations, including rising sea levels, a reduction in arable land, droughts, flooding, water shortages and diminishing food and fish stocks.

Such pressures could also lead to more disputes over territory and water supplies, exacerbating social and religious tensions and fueling the radicalization of the poor. Competition for energy resources is likely to increase and one flash point may be the Arctic, where melting polar ice caps are opening up new waterways and making enormous hydrocarbon resources accessible.

Last year, Britain told the United Nations that there were few greater threats to global security than climate change and predicted that competition for food, water and land could lead to armed conflict.

But some European diplomats argue that, while climate change is high on the political agenda, the focus tends to be on narrower issues such as carbon emission reduction targets.

EU heads of government are likely to ask for more detailed proposals on climate change and security by the end of the year. But the Solana study called for intensified research and monitoring so that Europe has early warning of impending disasters, as well as improving civil protection capabilities.

It also suggested more international cooperation both on combating climate change and its effects, building "carbon diplomacy" into the EU's dealings on the world stage.

At the summit meeting Thursday, EU leaders will review the goal they set last year of cutting carbon emissions by 20 percent by 2020. Draft conclusions for the meeting suggest that there should be agreement on the target "as a coherent package before the end of 2008," with laws put in place early in 2009.

But the Solana document argued that, even if the world manages to reduce carbon emissions to below half of 1990 levels by 2050, a temperature rise of 2 degrees Celsius (3.6 degrees Fahrenheit) would be difficult to avoid.

"Climate change and its impact on security is already a reality," said a senior EU official who works on the issue. "It is best viewed as a stress or threat multiplier which will worsen the existing tensions and threats."

The document suggested that climate change could trigger migration, including internal population shifts, in countries where health care is poor, unemployment is high and social exclusion is widely prevalent.

"The United Nations predicts that there will be millions of 'environmental' migrants by 2020 with climate change as one of the major drivers of this phenomenon," the document noted.

Migration may increase conflicts in "transit" and destinations countries, the report said, adding that: "Europe must expect substantially increased migratory pressure."

In the Middle East, water systems are already under huge stress with significant reductions in crop yields predicted. Climate change could also have a dramatic impact in South Asia, with serious consequences in Europe because of trading and financial links. Higher sea levels could threaten almost two billion people because 4 out of 10 people in Asia live within 60 kilometers, or 38 miles, of a coast.

Central Asia, Latin America and the Caribbean could also suffer from water shortages and declining agricultural productivity.

Source: International Herald Tribune