Land plants' carbon absorption already peaked in 2006, which we we didn't expect till 2030. Now soil carbon has a tipping point we didn't consider. Every new discovery seems to shorten our window to save ourselves.
A warmer world will release vast volumes of carbon into the atmosphere, potentially triggering dangerous climate change, scientists warn.
Writing in journal Nature, they project that an increase of 1C (1.8F) will release an additional 55 billion tonnes of carbon into the atmosphere by 2050.
This could trigger a "positive feedback" and push the planet's climate system past the point of no-return.
Previous assessments have not taken carbon released by soil into account.
In their Nature paper, an international team of scientists said that the majority of the Earth's terrestrial store of carbon was in the soil.
They warned that as the world warmed, organisms living in the planet's soils would become more active, resulting in more carbon being released into the atmosphere - exacerbating warming.
"There have been concerns about this positive feedback for a long, long time," said lead author Thomas Crowther, who conducted the research...
... the losses are going to be really considerable."
Using data stretching over 20 years from 49 sites across the globe, the team observed that global carbon stocks would fall by up to 55 petagrams (55 billion tonnes) under a business-as-usual scenario, which is roughly equivalent to adding the emissions from a nation the size of the US.
... our projection is that we are going to lose 55 petgrams, that's 55 trillion kilograms by 2050. This process is only going to accelerate and accelerate. [emphasis mine]
It’s also worth noting that 55 billion tons of carbon is roughly equal to 25 ppm of CO2 in the atmosphere. So adding that much over the next 35 years basically increases the net atmospheric CO2 accumulation rate by 0.7 ppm each year.
Continuing to burn fossil fuels has put us in a bad situation where Earth’s own carbon responses are being locked in.
... though it appears now that some carbon feedbacks are locked in, what we lock in by continuing on the BAU or near BAU path is an absolutely catastrophic situation. The urgency to halt emissions now could not be sharper. [emphasis mine]
Hear Dr Thomas Crowther on this study,
“It’s fair to say we have passed the point of no return on global warming and we can’t reverse the effects, but certainly we can dampen them,” said the biodiversity expert.
“Climate change may be considerably more rapid than we thought it was.”
“Our study shows that this major feedback has already certainly started, and it will have a significant impact on the climate in the coming decades. This information will be critical as we strive to understand how the climate is going to change in the future.”
“I think this is catastrophic for humanity,” said Dr Crowther.
Robert Scribbler explains the significance of this soil carbon release.
What this means is that even if all of human fossil fuel emissions stop, the Earth environment, from this single source, will generate about the same carbon emission as all of the world’s fossil fuel industry did during the middle of the 20th Century. And that, if human emissions do not stop, then the pace of global warming of the oceans, ice sheets, and atmosphere is set to accelerate in a runaway warming event over the next 85 years.
When initial warming caused by fossil fuel burning pumps more carbon out of the global environment, we call this an amplifying feedback. It’s a critical climate tipping point when the global carbon system in the natural environment starts to run away from us.
And it is also worth noting that the study categorizes its own findings as conservative estimates. That the world could, as an outside risk, see as much as four times the amount of carbon feedback ...
... amplifying carbon feedbacks from the Earth environment are probably starting to happen on a large scale now.
... even the optimists at this time think that we are on the cusp of runaway catastrophic global warming. That the time to urgently act is now.
Some part of me hopes that the rapidly declining environment will wake up the US citizenry, as the new administration demonstrates its total venality and incompetence, so that in four years we find the courage to turn toward global cooperation and sustainability. But we're already locked into a horror movie scenario, and that hope seems a will o' wisp.
I agree, "OH DEAR!"