Saturday, November 29, 2008

Putting destruction in context

The third headline on the BBC news website was "Amazon deforestation accelerates".  The article, in doom laden tones, usually consider appropriate by the BBC for environmental stories, states that:
The destruction of the Amazon rainforest in Brazil has accelerated for the first time in four years, Brazilian officials say. Satellite images show 11,968 sq km of land was cleared in the year to July, nearly 4% higher than the year before...

In recent years the Brazilian government has been able to celebrate three successive falls in deforestation. But the latest estimate from the National Institute for Space Research, known as INPE, shows that this trend has come to a halt.
Now, at a time that the world seems to be falling apart, with the terror attacks in Mumbai, protests in Thailand, the end of Western capitalism, and the assault by the Met police on Parliamentary sovereignty, you would think the ordering of BBC stories is strange. But the biggest sin, is the poverty of the story.

The lesser error is the suggestion that one year data can signal an end of a trend. To be honest, I wouldn't be sure that three years of downward data shows there is a downward trend; but there there is no way to tell whether this year's rise was a new trend or a blip.

But the howler is saying the 12,000 sq km were destroyed (as opposed to trees just being cut down) without any context.  How big is 12,000 sq km?

Using what seems to have been the international benchmark of choice when discussion Amazon destruction, 12,000 sq km is around half of Wales; that seems big.  A more appropriate comparison is that 12,000 sq km is but 0.2 per cent of the total rainforest area of 5,500,000 sq km.  Or put it another way, this rate of loss would have to continue for 50 years for the present rainforest to fall by 10 per cent; hardly disastrous.

So the bottom line of the story is there is no evidence that the slowdown of a already very slow fall in the Amazon rainforest has stopped.  A good news story.