Kris McDivitt thinks big. She plans to save 1.5m acres of South American wilderness and create four national parks. "This is our latest purchase," says the former head of the giant Patagonia clothing company as she looks at photographs of an Argentine swamp she bought last year.
Her new property will provide 280 species of birds with access to an environmentally rich habitat - and also allow her, and her husband Doug Tompkins, to escape the torrential rains that soak the huge areas they have also bought in Patagonia. In the past year, McDivitt has snapped up 260,000 acres of land in Argentina as she launches a non-profit foundation, the Patagonia Land Trust.
"We are just getting going in Argentina," she says flipping through a catalogue of the foundation's ecosystems. "It is an intact forest. Biodiversity can flourish and remain undisturbed." She concedes that some of the land will need 200 or 300 years to recover from overgrazing by sheep, but says that she sees her foundation guiding a master management plan "for the next 1,000 years".
On the other side of the Andes in Chile, Tompkins is equally ambitious. The co-founder of the billion-dollar North Face outdoor gear company has spent eight years buying land to make the 800,000-acre Pumalin Park - a temperate rainforest complete with snow-capped volcanoes and glacial fjords. He plans to give it to the government.
This couple, who own more than 2m acres in Chile and Argentina, are "eco barons", multi-millionaires buying swathes of wild, barely inhabited land around the world to conserve some of the world's remotest places.
Celebrities including Ted Turner (10,000 acres), George Soros (1m acres) and Luciano Benetton (2m acres) have also jetted down to South America to do their conservation bit. Sylvester Stallone, Jane Fonda and Michael Douglas are buying land. The same phenomenom is taking place in South Africa, where businessman Adrian Thompson has bought 45,000 acres, stocked them with lions and other mega fauna and, after ripping out all sign of previous human habitation in one 7,500-acre area, has had it declared Africa's first privately owned official wilderness area.
Meanwhile, Gordon Moore, co- founder of the giant Intel computer empire, last month gave $261m to the American charity, Conservation International to buy land and to carry out research in 25 of the world's most scientifically important biodiversity "hot spots" - mainly in Brazil and the tropics. Moore intends this to be just a downpayment on his plan to raise $6bn for conserving the world's most biologically rich places.
"There are more and more of these projects," says McDivitt. "People are very interested in leaving something more permanent than a wing on a museum. And, really, how many Citation jets can you own?" A second-hand 1998 Cessna Citation sells for about $3m, and land in Patagonia, the Amazon, South Africa and developing countries is very cheap. In many areas of Patagonia, ranches still sell for less than £20 an acre.
Tompkins bought his first 42,500 acres for just £250,000 and, having cut ties with their companies in the 1990s, the couple live in their remote Chilean homestead without electricity, computer, email or phone. They are surrounded by their vast properties - but also by the suspicions of people who question their intentions.
Tompkins and McDivitt have walked into a political minefield, and attacks against them have come in waves since they set up shop in Chile in 1994. Airforce jets have buzzed their retreat, they have received death threats and been accused of being a security threat, of planning a nuclear waste dump, setting up a Jewish homeland, and being American spies.
Meanwhile, church leaders have questioned Tompkins on everything from his opposition to population growth to his alleged support for US pro-abortion groups. Religious leaders lobbied the Vatican and Chilean public opinion to block the sale of Santiago university lands to Tompkins.
And the former president of Chile, Eduardo Frei, often lambasts the project. Frei says: "All indications that we have is that he threw the peasants off their land and that whenever there is development he blocks it. He won't allow free transit through [his land] and blocks the installation of salmon farms."
Tompkins is criticised also for his promotion of "deep ecology", the philosophy of the Norwegian Arne Naess, who argues that environmental destruction is so prolific that only a "deep" re-invention of modern society could reverse the pillaging of natural ecosystems. Naess contrasts this with "shallow" ecological trends - such as recycling or fuel-efficient cars - that he insists are temporary patches on a gaping wound.
"Our project ran into problems because it favours conservation and care for the environment, and confronts that runaway, pro-development juggernaut," says Tompkins. "It is an inevitable clash of concepts."
"The urban legends have died down," says McDivitt. "But what is literally painful is the accusation that we kicked people off their land. These farmers can't make it; they want to sell their land." Indeed, once the word leaked out that a pair of rich gringos were buying uninhabited - and, many say, uninhabitable - forest tracts, proposals flooded in.
Life for Tompkins in Chile is easier as he slows down his land purchase programme, learns to speak Spanish and signs agreements limiting his future land holdings. "We were clearly a little naive about the amount of political and non-political opposition we would face," he says. "We should have tried to know more, going in, about the political culture. We're getting better at that."
In an effort to integrate the few locals who live near his properties, Tompkins has set an ambitious plan to build trails, lookout points, bridges and a school.
Although he periodically announces that he is fed up with criticism and he might abandon Chile, people close to him say he is convinced that, in less than 10 years, his land will be converted into a new national park, ensuring his legacy. Tompkins says he wants people to copy his idea. "Those who can do a lot because of their position and potential should jump right in there. They will find tremendous pleasure in doing this, and discover that it is worth every penny."
Purchasing land for conservation is now a worldwide concern, with conservation groups such as the Ecology Fund and the World Land Trust buying up parts of the Amazon rainforest, oldgrowth forests in the US, and property in places as diverse as Scotland and the Lebanon. One British operation has put a down-payment on 20,000 acres of Patagonian coastland.
Conservation professionals see potential good and harm in it. "It depends on the country," says Chris Hail, international head of programmes at the Worldwide Fund for Nature. "It has to fit in with the development needs of the country. We prefer to ask what is the long-term sustainable plan for the country? When [huge areas] are owned by a private individual, you have to ask what happens when that person dies? Will it still be a national park in 100 years' time?"
Hail and others want to avoid people buying land and then trying to just preserve it, or throwing people out and locking up resources which could be used sustainably over years. Some countries are more open than others. Unlike the constant controversies in Chile, McDivitt's Patagonia Land Trust programme in Argentina has been heralded by politicians and the press as a godsend. "The distrust and paranoia about land conservation is much less in Argentina," she says. "All of our work has been accepted with open arms."
