It has never been easy to get figures for actual rainforest area - and our estimates based on what we could find had settled as follows:  There were about 8.0 million square miles of tropical rainforest in the world 150 years ago, and we’re now down to around 3.0 million square miles.

Absolutely devastated former forest, hopefully on track to regenerate. (Photo: WildMadagascar.org)

Climate change consists of three very distinct, only somewhat interrelated phenomena:  global warming, extreme weather, and droughts.  To reiterate:  Our position is that all three of these phenomena are worsened when tropical rainforests are lost - and that the climate consequences of tropical deforestation may be more significant than those that might result from burning fossil fuel.

An encouraging bit of information has surfaced from a study entitled “No Convincing Evidence for Decline in Tropical Forests“ authored by rainforest expert Dr. Alan Grainger from the University of Leeds in the U.K.  From compiling totals per nation as reported in the most comprehensive assessments of rainforest canopy available - studies released every ten years by the U.N. Food & Agriculture Organization, it appears that in the 63 nations with tropical rainforest, there is no measureable decline in the last 25 years!

In 1990 the FAO’s data determined total tropical rainforest declined from 7.4 million square miles in 1980 to 6.8 million square miles in 1990.  In 2000, the FAO data showed a decline from 7.4 million square miles in 1990 to 6.9 million square miles in 2000.  Apparently the FAO revised upwards their own 1990 baseline.

Grainger also performed his own analysis of the all-important moist tropical rainforest subset of tropical rainforests.  Back in 1983, his first assessment estimated moist tropical rainforest worldwide at 4.2 million square miles.  But when he did the analysis again in 2000, his estimate revised upwards, at 4.6 million square miles.

There is a lot to glean from all this.  First of all, it is heartening to know we probably don’t have 3.0 million, but 4.0+ million square miles of tropical rainforest left.  Secondly, this is encouraging testimony to the power of the earth in general, and rainforests in particular, to regenerate.

Probably most significant from all this is the fact that even now, with so many earth imaging satellites orbiting the planet we’re starting to worry about “space junk,” we still aren’t doing comprehensive assessments of the land use status of our planet.  Grainger has called for establishment of a “World Forest Observatory” to bring together researchers from around the world to compile - backwards through compositing archival earth imagery - far more accurate estimates of world rainforest canopy, updated at least every five years.

It is surprising this hasn’t happened already, and given the attention - and the dollars - being showered into climate change research,  Dr. Grainger’s recommendation should be implemented immediately.  The money’s there.  Maybe if they would shuffle a few million of the yearly $4.0+ billion currently going to fund climate change research to fund a few teams of forest cartographers, everyone would benefit, including the climate change researchers.

And while it is good to know these rainforests can often reestablish themselves, the industrialization of China (and the rest of Asia), combined with ongoing biofuel mania, means that there are profound new forces now working to accelerate the deforestation of the tropics.  Resetting the benchmark from 3.0 million to 4.0 million square miles of tropical rainforest feels good.  But alarm bells are still ringing off the hook.