Time, Scientific American, etc: Amazon Basin shifting from carbon sink, to source?


A long and densely illustrated review paper in Nature this week has a lot of ifs, maybes, and possibles in it but not enough to stop it from being troubling. Fifteen authors – the lead from Woods Hole Research Center with others from Brazilian and US institutions – decided after scouring the literature and combing through their own studies that the Amazon basin is changing in fundamental ways. Reasons include El Niño-type rhythms of drought and downpour and other more or less natural cycles, but land-clearing, agriculture, and climate change are the prime drivers, it says. Maybe. Or probably.

It says there are signs of a transition away from approximate equilibrium, and net absorption of carbon, to a “disturbance-dominated regime” and net emission of element #6 that had been stored in standing biomass and other organic matter. (If clicking doesn’t yield a higher-def version of Illus, try this).

Well sure, haven’t we been hearing this kind of thing for a long time? This review is the end-result of Amazon science workshops among the authors, members of something called the LBA or Large-Scale Biosphere-Atmosphere Experiment in Amazonia. It culminated in 2010 in Brazil at a NASA co-sponsored summit far from the Amazon, at a place on the Argentine border called Foz do Iguaçu that draws lots of tourists to its enormous waterfalls. It was appended to a “Meeting of the Americas” organized by the American Geophysical Union. One thinks that such details as that, culled from the paper’s closing acknowledgments and a few searches, are interesting as illustration of scientific culture and process,  and of how much goes into some reviews. These background tidbits don’t appear in news coverage, to no surprise. They might suggest to reporters however that the paper is far more authoritative on its topics than previous, individual studies. One wonders whether the AGU meeting had much of a press room and who was there and whether any reporters sat in on the Amazon huddle. But so far relatively few general news outlets have written the paper up at all for public consumption.


  • Scientific American – David Biello: Rainforest in Transition: Is the Amazon Transforming before Our Eyes? ‘ ; Biello’s opening angle is that among consensus conclusions is that much of the Amazon basin is putting on biomass at present – maybe still recovering from some long-ago disturbance. Then he gets into the transition toward carbon export that appears underway in its southern and western regions where farms and logging are expanding.
  • Time Magazine (blog) Bryan Walsh: Amazonia: What’s Happening to the World’s Biggest Rain Forest? ; Good first-person recall of the impossibility of grasping, in one thought, the region’s immensity and diversity. Then a series of passages from the paper itself.
  • AFPAmazon Basin shifting to carbon emitter: study ;
  • Nature – Paulo Artaxo: Break down boundaries in climate research ; Not journalism, but plain English and in the journal itself by one of the review’s authors. It is on the cooperative, sustained research effort by many agencies that led to the review. Nothing on the resort-city conference center session where the paper itself began to come together.

Grist for the Mill: Woods Hole Research Center Press Release ; Nature paper abstract ;

Charlie Petit