Bianca Jagger leaves no stone unturned Yet this is one environmental crisis that is quickly reversible. Scientific surveys have identified two billion hectares of degraded and deforested land worldwide - an area the size of South America - that can be restored to productive life. And in September last year, a group of governments and businesses set a target of rescuing 150 million hectares of them this decade, in the world's biggest ever restoration initiative. Jagger is the public face of a campaign, Plant a Pledge, to make the target a reality by getting firm undertakings to take action. So far, it has succeeded beyond expectation. By this stage, the plan was to have pledges for an area approaching seven million hectares. Counting the new commitments made at Doha, it now stands at 20 million: 15 million from the US Forest Service; two million from Rwanda: and a million each from Costa Rica, El Salvador and a coalition of government agencies, businesses and environmental groups in Brazil. India has indicated that it will be in for another 10 million hectares, while the Mesoamerican Alliance of Peoples and Forests has said it is good for 20 million: if these come good, the pledges will already cover a third of the target. Still, pledges are one thing, and putting them into practice quite another. Such projects won't get far unless the local people are fully involved: the drylands of the Third World are littered with failed tree-planting and anti-erosion schemes, imposed by "experts" from the national capital, or from overseas, with little regard to local conditions and traditions. By contrast, the people at the grassroots, as it were, have often proved remarkably successful. The International Union for Conservation of Nature, which runs Plant a Pledge, tells how people near Kenya's Lake Turkana restored 30,000 hectares destroyed by a refugee camp, through banning grazing livestock at the most sensitive time of year. Offenders were fined two animals - one of which was slaughtered, roasted and fed to the community. It cost the public purse just $100. Even more remarkably, farmers in Niger - in a project virtually unknown to the outside world -have restored some five million hectares, by protecting naturally regenerating trees. As a result, enough grain has been grown on previously barren land to feed two and a half million people. As land revives, there are more resources to go round: income grows, jobs are created, hunger and poverty shrink, and conflicts diminish. Climate change is tackled, too, since the growing vegetation absorbs carbon dioxide from the air: restoring 150 million acres is calculated to remove a billion tons a year. That, you might say, is how to get satisfaction. Something fishy in the water nets the Swiss a fortune It's known for its cheese, chocolate and even cuckoo clocks - but caviar? For those who can afford it, Switzerland is now selling the black golden eggs, produced in the heart of the Alps. The "Pure Swiss Alpine Caviar," as it is labelled, is the result of drilling for the new Loetschberg railway tunnel between the cantons of Berne and Valais some 10 years ago. Engineers were flummoxed when they hit hot water, geothermally warmed, gushing from the rock at a rate of 70 litres a second. They didn't know what to do, since discharging it into a nearby river would harm fish and plants. Then the chief engineer, who happened to have a Russian wife, had a brainwave. As a result, some 35,000 sturgeon now flourish in heated pools amid the snow-covered peaks. The plan is to end up with 60,000 of the fish, which happily adapt to warm waters and can grow to three feet long. That would yield three tons of caviar a year, which - at 3,000 swiss francs a kilo - should fill a few bank accounts. Has tunnel vision ever been so lucrative? Climate-change warriors turn to peace and progress For two weeks, the vast Qatar National Convention Centre, in Doha, has been full of deadlocked delegates refusing to budge, quibbling over commas, and shunning firm commitments. Except in one room, in a back corridor, where the same people fell over each other on Thursday to co-operate. Peter Kent, the Canadian environment minister - a bogeyman since his country left the Kyoto Protocol - helped put on the meeting alongside Lena Ek, his counterpart in admired Sweden. The unenthusiastic US came along with the militant Maldives. All promised action to combat climate change, even putting money on the table. What was different is that they were not discussing reducing carbon dioxide emissions, but attacking a range of "short-lived climate pollutants" such as black carbon, methane and HFCs - long, as readers may recall, a concern of mine - which account for about half of global warming. Last February, six countries and the UN Environment Programme pledged to tackle them outside the bogged-down climate negotiations; within 10 months, this has grown to 26 countries and five international organisations. No one can join without signing up to a programme of action - such as cleaning up smoky exhausts and distributing better stoves in poor countries. It isn't a substitute for dealing with carbon dioxide, but could buy time to do so. It's a pity the world didn't start with this low-hanging fruit, and build up some trust before grasping the prickly carbon dioxide pear.