The IPCC’s synthesis report, which draws together the state of climate science from three major Intergovernmental Panel on Climate Change (IPCC) assessments over the last two years, and three earlier shorter reports, was signed off by governments in Switzerland at the weekend.
The report concludes that human activities have “unequivocally caused global warming”, with global surface temperature reaching 1.1°C above 1850 - 1900 levels in 2011 - 2020.
It also notes that global greenhouse gas (GHG) emissions in 2030 implied by the nationally determined contributions (NDCs) announced by October 2021 make it “likely that warming will exceed 1.5°C during the 21st century and make it harder to limit warming below 2°C”.
“There are gaps between projected emissions from implemented policies and those from NDCs and finance flows fall short of the levels needed,” the report states.
The authors write that “every increment of global warming will intensify multiple and concurrent hazards”, and explains that “there is a rapidly closing window of opportunity to secure a liveable and sustainable future for all”.
António Guterres, the secretary-general of the United Nations, described the report as a “survival guide for humanity” which he said shows the 1.5 degree limit is achievable but will take a “quantum leap in climate action”.
“In short our world needs climate action on all fronts, everything, everywhere all at once,” he said in a media briefing, adding that “humanity is on thin ice and that ice is melting fast”.
According to the report, the solution lies in climate-resilient development. This involves integrating measures to adapt to climate change with actions to reduce or avoid GHG emissions in ways that provide wider benefits.
For example, the economic benefits for people’s health from air quality improvements alone would be roughly the same, or possibly even larger than the costs of reducing or avoiding emissions.
The report authors write that there are already tried and tested policy measures that can work to achieve deep emissions reductions and climate resilience if they are scaled up and applied more widely.
“If technology, know-how and suitable policy measures are shared, and adequate finance is made available now, every community can reduce or avoid carbon-intensive consumption. At the same time with significant investment in adaptation, we can avert rising risks, especially for vulnerable groups and regions”, the report states.
Speaking at the media briefing, Hoesung Lee, chair of the IPCC, said the report offers hope and provides a warning.
“It warns that the pace and scale of what has been done so far and current plans are insufficient to tackle climate change. We are walking when we should be sprinting.
“The impacts of human caused climate change are unfolding with bracing clarity, more intense droughts and flooding, threats to our food and water security, illness and death, the report shows that climate impacts are undermining our livelihoods, they are damaging the global economy and impacts threaten our life support system, the nature itself,” he said.
Dr Stephanie Roe, WWF global lead scientist climate and energy, and lead author on the IPCC Working Group III report, said the report represents the most comprehensive collection of climate science since the last assessment came out almost a decade ago.
“Weaving together the findings from the multi-thousand page reports published over the last few years, it very clearly lays out the devastating impacts climate change is already having on our lives and ecosystems all around the world, the harsh future we all face if we don’t get our act together, and the solutions we can implement now to reduce emissions and adapt to climate change.
“Some countries are already achieving sustained emissions reductions, but action is not yet at the scale or speed we need. With current emissions still at their highest level in human history, we are way off course, and the window to limit warming to 1.5ºC is rapidly closing.
“The sooner and more decisively we act, the sooner people and nature can reap the benefits of a cleaner, safer and more stable future. We have all the tools we need, so it’s well within our power to meet this challenge if we act now.”