\n<\/p>\n
The world is closer than thought to a \u201cpoint of no return\u201d after which runaway global heating cannot be stopped, scientists have said.<\/p>\n
Continued global heating could trigger climate tipping points, leading to a cascade of further tipping points and feedback loops, they said. This would lock the world into a new and hellish \u201chothouse Earth\u201d climate far worse than the 2-3C temperature rise the world is on track to reach. The climate would also be very different to the benign conditions of the past 11,000 years, during which the whole of human civilisation developed.<\/p>\n
At just 1.3C of global heating in recent years, extreme weather is already taking lives and destroying livelihoods across the globe. At 3-4C, \u201cthe economy and society will cease to function as we know it\u201d, scientists said last week, but a hothouse Earth would be even more fiery.<\/p>\n
The public and politicians were largely unaware of the risk of passing the point of no return, the researchers said. The group said they were issuing their warning because while rapid and immediate cuts to fossil fuel burning were challenging, reversing course was likely to be impossible once on the path to a hothouse Earth, even if emissions were eventually slashed.<\/p>\n
It was difficult to predict when climate tipping points would be triggered, making precaution vital, said Dr Christopher Wolf, a scientist at Terrestrial Ecosystems Research Associates in the US. Wolf is a member of a study team that includes Prof Johan Rockstr\u00f6m at the Potsdam Institute for Climate Impact Research in Germany and Prof Hans Joachim Schellnhuber at the International Institute for Applied Systems Analysis in Austria.<\/p>\n
\u201cCrossing even some of the thresholds could commit the planet to a hothouse trajectory,\u201d said Wolf. \u201cPolicymakers and the public remain largely unaware of the risks posed by what would effectively be a point-of-no-return transition.<\/p>\n
\u201cIt\u2019s likely that global temperatures are [already] as warm as, or warmer than, at any point in the last 125,000 years and that climate change is advancing faster than many scientists predicted.\u201d<\/p>\n
It is also likely that carbon dioxide levels are the highest they have been in at least 2m years.<\/p>\n
Prof Tim Lenton, an expert on tipping points at the University of Exeter in the UK, said: \u201cWe know we are running profound risks on the current climate trajectory, which we can\u2019t rule out could turn into a trajectory towards a much less habitable state of the climate for us. However, we don\u2019t need to be heading towards a hothouse Earth for there to be profound risks to humanity and our societies \u2013 these will already be upon us if we continue to 3C global warming.\u201d<\/p>\n
<\/span>Meltwater flows from the Greenland ice sheet into the Baffin Bay. Tipping may already been happening in Greenland and west Antarctica.<\/span> Photograph: Kerem Y\u00fccel\/AFP\/Getty Images<\/p>\n The assessment, which was published in the journal One Earth, synthesised recent scientific findings on climate feedback loops and 16 tipping elements. The tipping elements include the Greenland and Antarctic ice sheets, mountain glaciers, polar sea ice, sub-Arctic forests and permafrost, the Amazon rainforest and the Atlantic meridional overturning circulation (Amoc), a system of ocean currents that strongly influences the global climate.<\/p>\n Tipping may already be happening in Greenland and west Antarctica, with permafrost, mountain glaciers and the Amazon rainforest appearing to be on the verge, the scientists said.<\/p>\n \u201cResearch shows that several Earth system components may be closer to destabilising than once believed,\u201d they concluded. \u201cWhile the exact risk is uncertain, it is clear that current climate [action] commitments are insufficient.\u201d<\/p>\n Prof William Ripple, at Oregon State University, US, who led the analysis, said: \u201cThe Amoc is already showing signs of weakening, and this could increase the risk of Amazon dieback. Carbon released by an Amazon dieback would further amplify global warming and interact with other feedback loops. We need to act quickly on our rapidly dwindling opportunities to prevent dangerous and unmanageable climate outcomes.\u201d<\/p>\n Scientists warned in 2018 of the prospect of a hothouse Earth. In this scenario, global temperature stays significantly above the 4C rise of current worst-case climate scenarios for thousands of years, driving a huge rise in sea level that drowns coastal cities. The scientists said then that the \u201cimpacts of a hothouse Earth pathway on human societies would likely be massive, sometimes abrupt, and undoubtedly disruptive\u201d.<\/p>\n","protected":false},"excerpt":{"rendered":" The world is closer than thought to a \u201cpoint of no return\u201d after which runaway global heating cannot be stopped, scientists have said. Continued global heating could trigger climate tipping points, leading to a cascade of further tipping points and feedback loops, they said. This would lock the world into a new and hellish \u201chothouse<\/p>\n","protected":false},"author":1,"featured_media":44296,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[186,1208,187,589,9597,23018,6558,1007,384],"class_list":{"0":"post-44295","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-climate","9":"tag-closer","10":"tag-crisis","11":"tag-earth","12":"tag-hellish","13":"tag-hothouse","14":"tag-point","15":"tag-return","16":"tag-scientists"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/44295","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=44295"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/44295\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/44296"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=44295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=44295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=44295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}