Hysteria vs Truth

Here is an interesting bit of fact digging by Nigel Calder in his blog Calder's Updates. He documents the dramatic difference between what a doom-and-gloom fanatic said and the down-and-dirty truth. Who wins? Fact. The fanatic's hysteria was way overblown!

... an ecologist Philip Fearnside declared in 1982 that the Amazon forest was vanishing at an accelerating rate, with more than 40% to be gone by 1988. I told the tale in my 1991 book about remote sensing, Spaceship Earth, after visiting INPE in São Paulo.

During the 1980s Brazil found itself at war on two fronts. At home, the government tried to moderate the rate of clearances in the Amazonian forest, and police a frontier region as gun-happy as the old Wild West of the USA. Internationally, they had to deal with a rising chorus of criticism about the rate at which the forest was disappearing. In 1982, on the basis of INPE’s figures, predictions by an American scientist P.M. Fearnside amounted to a forecast that 44 per cent of the Amazonian forest would be lost by 1988.

The Brazilians greeted such estimates with frank disbelief. There then followed a contest between calculation and remote sensing to try to establish the true facts. …

In 1989, the World Bank published estimates indicating that 12 per cent of Legal Amazonia was already deforested by 1988. This was based on calculations from the state of affairs in 1980. By this time the Brazilians were growing very angry. Although the figure was far less than the Fearnside estimate, the fact that it came from the World Bank secured it a place in international environmental folklore. The Brazilians appealed again to the umpires in space: the unblinking instruments of the remote-sensing satellites.

At INPE, Roberto Pereira da Cunha decided to make a ‘wall-to-wall’ assessrnent of the deforestation in Legal Amazonia. As he remarked, ‘No one wants to do the dirty work of gathering the data. It is a very trivial task for scientists.’ Trivial, but not unlaborious. Pereira’s team assembled 234 Landsat scenes and selected for close interpretation 101 images that showed evidence of deforestation. From colour composites of three wavelength bands the scientists outlined the deforested patches, and used a grid to measure their areas. Images for different years established rates of deforestation.

The most important conclusion was that there was no acceleration: deforestation was proceeding at a more or less steady rate. As for the total recent deforestation up till the end of 1988, INPE’S answer was 5 per cent of the area of Legal Amazonia. Meanwhile, Fearnside had changed his forecast. His new figures indicated 7 per cent deforestation of Legal Amazonia by 1989 – a far cry from his 44 per cent figure of just 7 years earlier, and almost in line with INPE’s figure. In 1990 Jim Tucker and Chris Justice of NASA broadly confirmed the Brazilian result by a similar large-scale use of Landsat imagery, but with a different technique, using only a single infra-red channel.

So what do the umpires in space say now, two decades later?

The latest official figures from INPE cover 1988-2009 (see the Butler references). They show that deforestation in Amazônia Legal amounted to 377,000 sq. km. from 1988 to the end of 2009, out of a recently forested area of about 3,700,000 sq. km. That puts the loss at 10 % over 22 years. When added to the earlier INPE data they suggest that from 1970 to 2009 about 15 % of the forest has been cleared. Not good, but not catastrophic either, except for some indigenous people of the forest.

A briefing paper just out from Chatham House reports that actions by governments and businesses over the past ten years have cut Illegal logging by between 54 and 75 % in the Brazilian Amazon. Compared with ranching and farming, logging legal or illegal is a very small direct contributor to deforestation.

Even so the overall deforestation rate, according to INPE, has fallen from a peak of 29,000 sq. km. per year In 1995 to 7000 in 2009. That low rate of 0.2 % per year must be more than compensated by natural forest regrowth in some of the cleared areas. If it can be maintained, the shrinkage of the Amazonian rainforest will have been halted.

Supporting an optimistic view is a factor that environmentalists prefer to ignore – the fertilizing effect of the increasing carbon dioxide in the air, which all plants love. In 2008 Oliver Philips of Leeds and his colleagues reported a remarkable increase in rates of growth in the Amazonian trees, and concluded, “The only change for which there is unambiguous evidence that the driver has widely changed and that such a change should accelerate forest growth is the increase in atmospheric CO2.”

Fanatics of all stripes shoot themselves in the foot by constantly over-blowing their case. People get disgusted when the wild-eyed claims fail to come to fruition. Only the diehard fanatics stay on board to keep beating the drum for the fanatical claims. And like religious zealots, the true believers silently change their claims to cover their tracks while still making future claims that are over-inflated. They somehow think that making end-of-the-universe-as-we-know-it claims is the way to garner attention. Sure it gets attention. But it turns them into idiots.

Any claims that "the end is nigh" deserves a heavy dose of skepticism.