World is close to a ‘global tipping point
![]() By Helen Regan, CNN, November 28, 2019 , The Earth is heading toward a “global tipping point” if the climate crisis continues on its current path, scientists have warned, as they called for urgent action to avoid “an existential threat to civilization.”
The group of researchers, who published a commentary in the journal Nature, say there is growing evidence to suggest that irreversible changes to the Earth’s environmental systems are already taking place, and that we are now in a “state of planetary emergency.”
A global tipping point is a threshold when the planet’s systems go beyond the point of no return — such as the loss of the Amazon rainforest, accelerated melting of ice sheets, and thawing of permafrost — the authors of the commentary say.
Such a collapse could lead to “hothouse” conditions that would make some areas on Earth uninhabitable.
“We argue that the intervention time left to prevent tipping could already have shrunk towards zero, whereas the reaction time to achieve net zero emissions is 30 years at best,” the authors said.
Active problem areasLed by Timothy Lenton, professor of climate change and Earth system science at the University of Exeter, in southwest England, the team identified nine areas where they say tipping points are already underway.
Those include widespread destruction of the Amazon, reduction of Arctic sea ice, large-scale coral reef die-offs, melting of the Greenland and West Antarctic ice sheets, thawing of permafrost, destabilizing of boreal forests — which contain vast numbers of trees that grow in freezing northern climes — and a slowdown of ocean circulation.
The team claims that these events are interconnected and change in one will impact another, causing a worsening “cascade” of crises………
.
The UN Environment Program (UNEP) 2019 Emissions Gap report said at the current rate, temperatures are expected to rise 3.2 C by 2100.
Greenhouse gases reached a record high in 2018 with no sign of peaking, according to a recent World Meteorological Organization report. Carbon dioxide levels reached 407.8 parts per million, a unit used to measure the level of a contaminant in the air.
Hope is not lost, however. Researchers say that mitigating greenhouse gas emissions could still slow down the accumulation of these climate impacts.
What is needed, they say, is urgent international action to cut emissions, slow sea level rise, and to keep warming to 1.5 C.
“A saving grace is that the rate at which damage accumulates from tipping — and hence the risk posed — could still be under our control to some extent,” they said.
“The stability and resilience of our planet is in peril. International action — not just words — must reflect this.” https://edition.cnn.com/2019/11/28/health/climate-crisis-global-tipping-point-intl-hnk/index.html?utm_source=twCNN&utm_content=2019-11-30T05%3A01%3A06&utm_term=link&utm_medium=social
|
|
No comments yet.
Leave a Reply