IPCC Synthesis Report AR6: the outcome of the global interdisciplinary dialogue on climate change is a message of urgency and hope

At the end of its 58th session, taking place in Interlaken, Switzerland, the Intergovernmental  Panel on Climate Change (IPCC) released the Synthesis Report of the Sixth Assessment  Cycle on Monday, March 20, 2023. 

On the dedicated official website , the Summary for Policy Makers (SPM) and the longer report are now available, together with the figures representing data in the Synthesis Report (SYR)  and its headline statements. The full volume is coming soon.  

The SYR summarizes the findings of the reports respectively produced during the Sixth  Assessment Cycle: the contributions of the three IPCC Working Groups (respectively on the  physical basis of climate change; on impacts, adaptation, and vulnerability; on climate change  mitigation) and the three Special Reports (respectively on global warming of 1.5°C, on oceans and  the cryosphere, and on land use). The reports are based on peer-reviewed literature published  since the conclusion of the previous assessment cycle in 2014 and until 2019; the process  involves more than one thousand authors with different backgrounds from all over the world. This  SYR has a new structure if compared with previous ones, aimed at better integrating  multidisciplinary knowledge from the different Workin Groups and providing relevant information  on near and long-term climate change and possible climate action. 

The effort of the SYR authors toward the accessibility of the information is noticeable. As usual,  the report is written in the so-called calibrated language, the distinctive feature of the IPCC  publications: each finding is grounded in an evaluation of underlying evidence and agreement. A  novelty of the SYR has italicized annotations in the figures, to help non-experts navigate complex  content, while online tools are available for readers with different expertise to navigate through the  panel’s findings, such as the WGI Interactive Atlas and the WGI SPM Figure Explorer. Some of the straightforward figures of this SYR are destined to become iconic. Figure  SPM.1 effectively represents how the extent to which current and future generations will  experience a hotter and different world depends on choices taken now and in the near term. 

It is relevant that this report is destined to inform the first Global Stocktake of the implementation  of the Paris Agreement under the UNFCCC, which will be concluded during the 28th Conference  of the Parties of the FCCC (COP 28), taking place in Dubai from November 30 until December 12,  2023. The Global Stocktake is a critical juncture as it will show whether countries and other  stakeholders are making progress toward the achievement of the goals agreed upon in the Paris  Agreement (“holding the increase in the global average temperature to well below 2 °C above pre industrial levels and pursuing efforts to limit the temperature increase to 1.5 °C”). 

According to the SYR, they are not: the report states there is high confidence that “global  greenhouse gas emissions have continued to increase, with unequal historical and ongoing  contributions” and “global GHG emissions in 2030 implied by 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”. The report carves into stone that “human  activities, principally through emissions of greenhouse gases, have unequivocally caused global  warming, with global surface temperature reaching 1.1°C above 1850–1900 in 2011–2020”, and  that human-caused climate change has already led to impacts, losses, and damages to nature  and people, while “every increment of global warming will intensify multiple and concurrent  hazards”. 

This discouraging picture is followed by a message of urgency and hope: there is high  confidence that “deep, rapid, and sustained reductions in greenhouse gas emissions would lead  to a discernible slowdown in global warming within around two decades”. Nonetheless, some  future changes are unavoidable, but adaptation measures are available and should be taken today  before they become more constrained and less effective. According to the IPCC Chair Hoesung  Lee “mainstreaming effective and equitable climate action will not only reduce losses and  damages for nature and people, it will also provide wider benefits” (IPCC press release).

Written by Elena Nalato (PhD SDC candidate)