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World likely to breach 1.5°C by early 2030s – IPCC report
Only immediate action to curb greenhouse gas emissions can still prevent the worst climate outcomes, according to a new report by the world's leading authority on climate change.
The Intergovernmental Panel on Climate Change (IPCC) – the United Nations body for assessing the science related to climate change – has issued its most dire warning yet on the state of the natural world. In the first part of its sixth assessment report (AR6), published to much fanfare in August, the IPCC concluded that climate change is ‘already affecting every inhabited region across the globe’ and that human influence has triggered far-reaching changes to the atmosphere, ocean, cryosphere and biosphere.
These conclusions may seem evident to many populations in the Northern Hemisphere, which endured record-breaking heat and wildfires this summer. However, the report is significant in that it establishes an ‘unequivocal’ link between anthropogenic emissions and extreme weather events. The group’s last assessment report, AR5, published in 2013–14 only concluded that warming had been observed, and did not assign firm causation to human activities.
As is the norm at the IPCC, the AR6 assessment cycle was subdivided into three working groups: the first was tasked with looking at the physical science basis for climate change, the second is exploring impacts, adaptation and vulnerability and the third is looking at the issue of mitigation. The findings of working groups two and three are scheduled for publication in spring 2022, while a final synthesis report is expected later that year.
The first installment of AR6 concluded that, in almost all emissions scenarios, global temperature rise will reach 1.5°C in the early 2030s. The climate system will also continue to warm until net zero carbon emissions are attained. At 1.5°C, there will be increased heatwaves, shorter cold seasons and longer warm seasons – while 2°C would bring heat extremes that put agriculture and human health under serious strain.
Temperature rise also brings with it a host of other impacts – which increase with further warming. Findings include the fact that climate change is intensifying the water cycle, bringing more intense rainfall and flooding in many regions. Precipitation is likely to increase at high latitudes, while it will decrease over large swathes of the subtropics.
Throughout this century, low-lying areas can expect to see more frequent and severe flooding, as well as coastal erosion. Once-in-a-century sea level events could happen every year by 2100 if emissions are not tackled urgently and permanently. However, although the IPCC avoids making prescriptive recommendations to policymakers, its latest report suggests that human societies still have the power to determine the severity of global heating.
‘Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO2 emissions,’ says IPCC Working Group I Co-Chair Panmao Zhai. ‘Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate.’
In a break with convention, a small group of scientists leaked the draft of the third part of AR6 to the Spanish media in mid-August. Those involved reportedly feared their conclusions could be watered down by governments before the report’s publication. The draft said that GHG emissions must peak in the next four years, while coal and gas-fired power stations must be mothballed in the coming decade. The IPCC did not comment on the leak.