Now here's some really good news. Deforestation in the Amazon - poster child for the world's rainforests - has plunged to unprecedentedly low levels. Indeed, at around 6,500 square kilometers this year, less than a quarter as much has been felled as in 2004. Admittedly that was a peak year, if not quite the worst ever; that dubious distinction belongs to 1995, but it has fallen steadily for five of the last six years, the most sustained reduction on record.

Much of this is down to deliberate action by the government of outgoing President Luis Inacio Lula de Silva, which has enforced the country's Forest Code and cracked down on illegal logging. So successful has it been that it recently brought forward its target for achieving an 80 per cent cut in deforestation by four years: not to be satisfied, a coalition of environmental groups is pressing for it to be reduced to zero by 2015.

All this is excellent news for wildlife species (which achieve their greatest terrestrial abundance in rainforests), for the indigenous people who depend on the forest, and even for Brazil's food supplies - since the rains that water its southern breadbasket are generated by the Amazonian trees. But it is also important for the climate.

Felling trees - and burning them or letting them rot - releases carbon dioxide: deforestation worldwide is responsible for around a fifth of the emissions of the principal greenhouse gas from human activities. Brazil's reduction, the Union of Concerned Scientists calculates, now adds up to an emission cut of 870 million tonnes of it each year. That makes the country far and away the world's champion at tackling global warming, far outdistancing even the greenest industrialized country: for comparison, even if all the countries of the European Union fulfills its pledge to cut emissions by 20 per cent by 2020, they will still have less of a reduction, some 850 million tonnes annually.
But this progress could yet be reversed. Amendments to the Forest Code proposed in the Brazilian Congress, and backed by agricultural interests, could create loopholes that would send deforestation rates rising again. Everyone is waiting to see if Lula’s protégée president-elect Dilma Rousseff, shares his commitment to conserving Amazonia.