by Cornelia Rumpel, for Nature News and Views
“Carbon has been stored in the organic layers of boreal-forest soils for hundreds of years. An analysis reveals that this carbon might be released into the atmosphere as global warming increases the frequency of wildfires…”
“Boreal forests are key players in the global carbon cycle, because they store 30–40% of terrestrial carbon1. They have been considered to be carbon sinks, mainly because they accumulate large amounts of carbon in the form of organic soils2. Their net carbon balance is driven by natural wildfires (Fig. 1), which produce large carbon emissions approximately every 70 to 200 years3, and which are necessary to maintain the productivity and biodiversity of these forests. But climate change is likely to shorten the period between fires (the fire-return interval) by producing warmer temperatures, more lightning strikes, longer wildfire seasons and drier forest conditions than those seen at present4. In a paper in Nature, Walker et al.5 show that the increase in fire frequency might turn boreal forests from carbon sinks into carbon sources.
“The cause of this shift is due to the impact of more-frequent fires on legacy carbon — the organic carbon that has escaped earlier fires and has accumulated at the surface of boreal- forest soils. A boreal forest will act as a carbon sink if a fire removes less soil carbon than the amount that accumulated after the previous fire — or, to put it another way, if the soil carbon removed by a fire is younger than the community of trees affected by the fire.”
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Transformation may ignite runaway climate change if humanity fails to act
This transformation process, from sink to potential carbon emission source has been identified as a highly likely instigator of runaway climate change if the Earth moves beyond 2C temperature change from pre-industrial levels by numerous climatologists. The greatest sink for anthropogenic carbon are the oceans. If the boreal soils reverse role from sink to source of carbon, along with the oceans, we will have little time to act…
Year 2000: Density of global forests cover. Note the key TROPICAL regions are the Amazon Basin, the Congo Region of Central Africa, and Indonesia/Malaysia. Key BOREAL forests are Canada, Russia, and Siberia. Key to every MapX directly below it. (courtesy: MapX; UNBiodiversity N6; UNEP)
Year 2018: Global Forest Loss since base year of 2000. (2018-2000)/.
Year 2013-2018 : Fire Locations. Te pixelation of off Brasil’s eastern coast appears in most satellite data and imaging, and attributed to burning embers carried loft and held aloft for at least one pass of the recording satellites.
In the Amazon, this loss has been definitively attributed to slash and burn techniques associated with the expansion of farms and cattle ranches in countries such as Brasil through analysis of NASA and GOES satellite data
Millions of hectares of pristine tropical rainforest were destroyed in 2018, according to satellite analysis. Losses were also high in the Democratic Republic of the Congo
Indonesia is the only major country with substantial TROPICAL forests where government protections and protection-on-the-ground appear to be significantly reducing the losses caused by fire.
Governments and People, today, can have a significant effect in reducing damage to forests and improving biodiversity.
“It is really tempting to celebrate a second year of decline (2017; 2018) since peak tree cover loss in 2016 but, if you look back over the last 18 years [since Year 2000], it is clear that the overall trend is still upwards,” said Frances Seymour from the World Resources Institute, part of the Global Forest Watch network. Her words proved prophetic in the devastating yer, 2019, when the Wolrd gasps t the loss of Amazonian Rainforests, and a new term entered the lexicon of every household – “Amazon – Lungs of The World.”
“The world’s forests are now in the emergency room – it is death by a thousand cuts,” she said. “Band-Aid responses are not enough. For every hectare lost, we are one step closer to…a scenario of runaway climate change,” Seymour said.
At the same time, Ghana and Ivory Coast recorded the biggest percentage rises in rainforest destruction, driven by gold mining and cocoa farming. African cocoa is the source of most chocolate in the World.
All MapX generated using publicly available databases by Dr. Kenneth Michael Beck for this post. You can do it too!