They’ve now passed a median threshold for the risk of mass dieback calculated at 1.2 degrees Celsius of global warming.<\/p>\n
WA’s ‘catastrophic’ bleaching event<\/a><\/p>\n In Western Australia, the damage to coral reefs including the World Heritage-listed Ningaloo has eclipsed any previous bleaching events.\u00a0<\/p>\n Tim Lenton, a University of Exeter professor and climate modeller who led the report, said tipping points could no longer be talked about as a “future risk”.<\/p>\n “The first tipping point of widespread dieback of those warm water coral reefs is already underway,” he said.<\/p>\n “That’s impacting hundreds of millions of people who depend on the reefs for fishing, tourism and coastal protection from rising sea levels and storm surges.”<\/p>\n What are Earth’s tipping points?<\/p>\n The Earth’s interconnected systems are split across three main categories: the cryosphere (ice), biosphere (living things), and the ocean and atmosphere.<\/p>\n The first tipping points report in 2023<\/a> identified 25 aspects of these categories that could “tip”.<\/p>\n This means they might abruptly change to a different state, and that change is likely to be irreversible within a human’s lifetime.<\/p>\n For the world’s reefs that means coral could be replaced by algae cover.<\/p>\n David Obura, a marine ecologist and coral expert from Coastal Oceans Research and Development in the Indian Ocean East Africa, helped put together the first tipping points report.<\/p>\n He said coral reefs that go past the tipping threshold were highly likely to remain changed.<\/p>\n “Past the threshold doesn’t mean forever, if we can return below the threshold,” he said.<\/p>\n “But if conditions remain past the threshold, then that tipping point is very real, and permanent on human timescales.<\/p>\n Dr Obura stressed we had not yet gone past the upper limit of the tipping point threshold for coral reefs, which is 1.5C.<\/p>\n “Unless the right actions are taken globally, urgently, on climate drivers … the increasing climate pressure means that all reef regions will approach their tipping points, and some may cross them.”<\/p>\n Other global tipping points include the melting of ice sheets, forest dieback and changes to ocean circulation.<\/p>\n Global tipping points include coral reef die-offs, the collapse of ice sheets and changes to ocean circulation. (Supplied: Global Tipping Points Report 2025, CC-BY-SA 4.0<\/a>)<\/p>\n Each tipping point has a different estimated threshold <\/strong>in a warming climate and the risk of these being breached rises with every 0.1C rise in global temperatures.<\/p>\n But understanding how they would then interact with each other and what cascading impacts might occur from collapses is hard to predict.<\/p>\n The world is aiming to keep the increase in long-term average temperatures, since the industrial revolution, to 1.5C or under 2C.<\/p>\n We’re currently on track to see surface temperatures warm by as much as 3.1C, come 2100<\/a> based on current decarbonisation policies of international governments.<\/p>\n<\/p>\n