For A New World View, chapter 5. Excerpt: Sensor-studded plots in the Amazon forest will measure the fertilizing effect of the gas. ...The ways in which rising carbon dioxide levels will affect the Amazon rainforest are still highly uncertain. ...One of the wild cards in climate change is the fate of the Amazon rainforest. Will it shrivel as the region dries in a warming climate? Or will it grow even faster as the added carbon dioxide in the atmosphere spurs photosynthesis and allows plants to use water more efficiently? A dying rainforest could release gigatonnes of carbon into  the atmosphere, accelerating warming; a  CO2-fertilized forest could have the opposite effect, sucking up carbon and putting the brakes on climate change. Climate modellers ... have had  precious few data to go on.  ...Now an international team of scientists is developing an ambitious experiment in the central Amazon that ... would bathe a patch of rainforest in extra CO2 and, over the course of a decade or more, measure how the plants respond....  http://www.nature.com/news/experiment-aims-to-steep-rainforest-in-carbon-dioxide-1.12855 ,  Jeff Tollefson, Nature.