The linked article uses wildfires in the Amazon as a canary in a coal mine to indicate that the rainforests have turned from carbon sinks to carbon sources:
Title: "Record Amazon fires stun scientists; sign of sick, degraded forests"
https://www.skepticalscience.com/2017-SkS-Weekly-News-Roundup_41.htmlExtract: "- With the fire season still on-going, Brazil has seen 208,278 fires this year, putting 2017 on track to beat 2004’s record 270,295 fires. While drought (likely exacerbated by climate change) worsens the fires, experts say that nearly every blaze this year is human-caused.
- The highest concentration of fires in the Amazon biome in September was in the São Félix do Xingu and Altamira regions. Fires in Pará state in September numbered 24,949, an astonishing six-fold increase compared with 3,944 recorded in the same month last year.
- The Amazon areas seeing the most wildfires have also seen rapid change and development in recent years, with high levels of deforestation, and especially forest degradation, as loggers, cattle ranchers, agribusiness and dam builders move in.
- Scientists warn of a dangerous synergy: forest degradation has turned the Amazon from carbon sink to carbon source; while globally, humanity’s carbon emissions are worsening drought and fires. Brazil’s rapid Amazon development deepens the problem. Researchers warn that mega-fires could be coming, unless trends are reversed.
See also the associated article at:
https://news.mongabay.com/2017/10/record-amazon-fires-stun-scientists-sign-of-sick-degraded-forests/Extract: "While in the past Amazonian forests served humankind inadvertently by absorbing more carbon than emitted, delaying the worst impacts of global warming, Feldpausch says that has now changed. The Amazon has now become part of the problem: “The combined effect of continued droughts, fire, and forest degradation is reducing carbon stocks, resulting in Amazon forests being an estimated net source of carbon during the past decade.”
Indeed, a new, just published study by researchers at the Woods Hole Research Center and Boston University, has found that human-caused deforestation, forest degradation and disturbance of tropical forests in Africa, the Americas and Asia have resulted in those forests now emitting more carbon into the atmosphere than they sequester on an annual basis."