Have one-half of the world’s forests been converted to non-forest use?

I posted recently “You’re pulling my Yang. Ten reasons to use dead tree stuff,” the Yang being half of the Taoist Yin-Yang concept of male/female, light/dark/ ebb/flow, action/reaction. The post’s message was that we can’t look at only one side of an issue as a Yahoo Green blog had done (10 big reasons to stop using dead trees). In this post, my objective is to give you tips on double-checking the statistics tossed about in the green war for your wallet. One of the places the Yahoo blog had gathered its statistics was a report by the Environmental Paper Network (EPN), “The State of the Paper Industry: Monitoring the Indicators of Environmental Performance.” According to this report (and the Yahoo Green blog paraphrased), “Roughly half the world’s forests have been burned or cleared and converted to non-forest uses. Human activity has degraded almost 80 percent of what remains of the planet’s once vast forests.” This sounds troubling, if it proves to be true.

I’m Skeptical

Of course, EPN crafted this factoid to sound troubling. You’ll make rash decisions if a gun is pointed at you, won’t you? Words matter. This rhetoric is designed to get you to take action, specifically grabbing your credit card and giving money to continue the fight. “Crisis, real or not, is a commodity,” Tom Knudson wrote in his 2001 series, Environment, Inc., “And slogans and sound bites masquerade as scientific fact.”

I’m also skeptical because of the organizations that EPN is affiliated with, including Tzeporah Berman‘s ForestEthics–an organization that, according to writer Mark Leiren-Young, “works with and/or bullies businesses into better environmental practices.” ForestEthics and World Wildlife Fund use “gray sources” and that will lead me to be more skeptical of the purported facts quoted. Ms. Berman contributed her ‘expertise’ to Leonardo DiCaprio‘s climate-change documentary, The 11th Hour.

The 11th Hour (film)

Image via Wikipedia

Ms. Berman told the film’s producers, “I think you need to look at the world’s resources and data showing that’s showing that 80 percent of the world’s intact forests are already gone…” To which I would have said, “show me the data,” but they said, “Who are you?”

She was hired for that as a consultant after piping up at a Bioneers‘ Conference in Marin, California, “I think,” she told the group who turned out to be the movie’s producers and directors, “you need to look at the world’s resources and data showing that’s showing that 80 percent of the world’s intact forests are already gone and there are only three countries left in the world with enough forests to maintain biodiversity and ecosystem services. And that’s Canada, Russia, and Brazil.” To which I would have said, “show me the data,” but they said, “Who are you?”

There are two parts to this: (1) Conversion of roughly half the earth’s forests and (2) Degradation of roughly 80% of our present forests. Let’s start with the conversion question.

Have roughly half the world’s forests been burned or cleared and converted to non-forest use?

Probably not. In his book “The Skeptical Environmentalist,” Bjørn Lomborg states that most authorities put the figure around 20 to 25 percent.

Of course, this is disputed by Emily Matthews, then with the World Resources Institute. Although she concedes, “Andrew Goudie [one of the authorities Lomborg cites], indeed gives a figure of 20 percent net loss in forest cover since pre-agricultural times. However, its author provides no reference or authority for this number.” Of course, neither does she state why this is incorrect. She does state, “Lomborg confusingly contrasts net loss of forest cover (that is, his figure of loss of natural forest offset by regrowth and new plantations) with loss of original forest (WWF‘s figure).”

Apparently, then, the contention is that one-half of the earth’s remaining forests have never, ever, been used for firewood, burned for plentiful game the following season, logged, or otherwise used for mankind’s purposes. I think the number is low because before humans developed agriculture, they used fire to change the forest’s composition to assure that young and tender new growth was there to attract game they could hunt.

Source: World Resources Institute

The terms do get slippery, don’t they? “Original forest” can mean pretty much whatever you want it to mean; it does not appear in the definitions of the Food and Agriculture Organization of the United Nations (FAO). The closest to what might be termed “Original” is the “Primary Forest” where the effects of humans no longer appear present. The FAO doesn’t fret about deep ecology or try to compare our current forests to forests before humans walked on two legs. They know we are in the Anthropocene Epoch. To the FAO deforestation and conversion mean the same thing: the change of use of the land (not the forest or its composition) to another land use or reducing tree canopy cover below 10 percent for a long time.

So, have half of the world’s forests been converted? That all depends on whose definitions you want to use. I would use Lomborg’s figure of 20-25 percent, since he uses FAO definitions and sources his number.

What do you say? Do you have any numbers to show that the earth has lost 1/2 of its forests?

Has human activity degraded almost 80 percent of what remains of the planet’s once vast forests?

I’ll get to that in the next post.


  • Deforestation (aka Conversion), “the conversion of forest to another land use or the long-term reduction of tree canopy cover below the 10% threshold.” (My emphasis)
  • Degradation, “the long-term reduction of the overall potential supply of benefits from the forest, which includes wood, biodiversity and any other product or service.”
  • Forest, “Forests are lands of more than 0.5 hectares, with a tree canopy cover of more than 10 percent, which are not primarily under agricultural or urban land use.”


Lomborg, Bjørn.,The Skeptical Environmentalist: Measuring the Real State of the World. Cambridge University Press. 2004 p.16


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