THE growing number of people who migrate from developing countries to over-populated Western states in search of a better life is damaging the planet and could be avoided, a think-tank said Tuesday.
Governments and aid agencies should encourage families to stay put by tackling environmental degradation, such as the spread of deserts, that forces many to leave, rather than promote migration, said the Optimum Population Trust (OPT), a British group that campaigns for a sustainable population.
At the same time, Britain should continue to fulfil its humanitarian obligation to genuine refugees and asylum-seekers, the think-tank said in evidence to a parliamentary inquiry on population.
Parts of the planet that have been damaged by climate change, soil erosion and water shortages merely deteriorate further once their inhabitants flee.
In addition, migrants typically increase their ecological footprint-the damage each person inflicts on the environment - - by moving from low- to high-consuming countries.
"The priority must surely be to prevent or cure environmental damage, and help people to remain in their homes and communities, not abandon damaged areas of the planet to their fate," the OPT said in a report.
The ecological footprint of someone from Bangladesh increases 16- fold if he or she emigrates to the United States, while that of a Somali citizen rises more than 13-times when he or she migrates to Britain.
The push factors behind migration can only be solved by reducing the impact of consumption and population in richer countries and supporting environmentally-sustainable development in poorer nations, the OPT said.
"Currently, however, excess immigration into countries which are already densely populated can cause substantial environmental damage and economic costs, the effects of which may not be seen until the pressures on land and natural resources become intense," it warned.
Britain, for example is more densely populated than China.
England alone is the world's fourth most crowded country-behind Bangladesh, South Korea and the Netherlands-with migration accounting for more than 80 percent of population growth.
"With parts of the country already facing serious water supply problems, population growth on this scale will make the UK increasingly vulnerable to resource and energy shortages and will increase its contribution to climate change," the think-tank warned.
OPT patron Professor Aubrey Manning said Britain was morally obliged to accept some migrants "but we need immigration like we need a hole in the head."
On a global scale, he said: "People are in surplus and often those most needed at home are those who leave. A gradual reduction to our population is the only way to secure any quality of life for future human beings."
The total number of migrants worldwide surged from 175 million to 185-to-192 million between 2000 and 2005, the group said.
Of these, an estimated 30 million migrants were forced from their homes by environmental factors, including floods, famine and over- population.
Environmental degradation is seen forcing a further 135 million people out of their homes in the future.
Such migration coupled with ongoing population growth is undermining efforts to meet the United Nations' Millennium Development Goals, the think-tank added.
It advised governments to work out what populations could be sustained, with the best quality of life and without causing environmental damage elsewhere.
The OPT believes the planet may not be able to support more than half its present population of some 6.58 billion people in the next century.
Meanwhile, another report from Los Angeles adds: A volunteer militia that conducts its own unofficial patrols of the US-Mexico border started building a fence Saturday aimed at stopping illegal immigrants from entering the United States.
The civilian border patrol, called the "Minutemen," which advocates a tough approach to illegal immigration, held the ground-breaking ceremony in the southwestern state of Arizona on private land adjacent to Mexico.
The fence represents a first step in the militia's plans to construct fences and barriers along the 3,000 kilometer (2,000- mile) common border which it says the US government has failed to secure.
"Many have talked of building a secure fence between Mexico and the United States," the Minuteman Civil Defense Corps said on its website, www. minutemanhq.com.
"Now ... MCDC is taking action again and doing the job the federal government will not do," the organization said.
A spokeswoman for the MCDC, Connie Hair, told AFP by telephone: "We laid ground for the foundations and we're about to raise the fence."
Several hundred people, including Minutemen and local politicians, attended the ceremony, she said.
The fence, some two meters (6.5 feet) high and 16 kilometers (10 miles) long, is an initial step toward a more sophisticated security system for which the Minutemen are trying to raise funds nationwide.
The grassroots group adopted the name of the Minutemen, an elite militia that played a role in the 1775-1783 US war of independence from England.
It has been patrolling the US-Mexico border since April 2005. The volunteers help the US Border Patrol to spot illegal immigrants, but are not authorized to arrest them.
Saturday's fence action occurred at the start of the long Memorial Day holiday weekend, when the US remembers its war dead.
And it came as the US Congress debates immigration reform, an emotional issue that has divided this nation built on immigrants.
The Senate approved a bill this week that would create 200,000 temporary work visas for foreigners who take low-skill jobs here, and double the number of US Border Patrol agents on the border with Mexico.
Most controversial is a provision that would allow many of the estimated 11.5 million foreign workers here illegally, many of them Mexican, to gain legal status.