What is the IPCC AR6 Synthesis Report and why does it matter?
What is the IPCC AR6 Synthesis Report and why does it matter?
The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the scientific basis of climate change, its impacts and potential future risks, and possible response options. The IPCC produces comprehensive assessment reports every six to seven years that summarize the current state of knowledge on climate change and its implications for society and the environment.
The Sixth Assessment Report (AR6) is the latest and most comprehensive report by the IPCC, which consists of three Working Group contributions and a Synthesis Report. The Working Group I report, released in August 2021, focused on the physical science basis of climate change. The Working Group II report, released in February 2022, assessed the impacts, adaptation and vulnerability of human and natural systems to climate change. The Working Group III report, released in April 2022, examined the mitigation of climate change and the pathways to limit global warming to well below 2°C or 1.5°C above pre-industrial levels.
The Synthesis Report, released in March 2023, integrated the findings of the three Working Group reports and provided a concise and policy-relevant summary of the key messages and implications of the AR6 for decision-makers and stakeholders. The Synthesis Report was based on the approved Summary for Policymakers and adopted Longer Report of each Working Group contribution, as well as other relevant IPCC reports.
The Synthesis Report addressed four main topics:
- The current state of the climate system and its changes
- The future projections of climate change and its impacts under different scenarios
- The adaptation and mitigation options and their co-benefits and trade-offs
- The enabling conditions and challenges for implementing effective and equitable climate action
The Synthesis Report highlighted that human influence has been the dominant cause of observed warming since the mid-20th century, and that rapid and unprecedented changes in all aspects of the climate system are already occurring across all regions and ocean basins. It also warned that further warming will amplify existing climate risks and create new ones for natural and human systems, with some impacts being irreversible or very long-lasting.
The Synthesis Report emphasized that limiting global warming to 1.5°C or 2°C above pre-industrial levels would require rapid, deep and sustained reductions in greenhouse gas emissions, as well as reaching net zero CO2 emissions by around mid-century. It also stressed that adaptation is essential to reduce the unavoidable consequences of climate change and enhance resilience, but that it has limits and cannot prevent all losses and damages.
The Synthesis Report underscored that both adaptation and mitigation actions can provide multiple co-benefits for sustainable development, human health, biodiversity, equity and justice. It also pointed out that achieving these co-benefits requires addressing the interlinkages and trade-offs among different goals and actions, as well as enhancing cooperation and coordination at all levels of governance.
The Synthesis Report concluded that there is still a narrow window of opportunity to avoid the worst impacts of climate change and achieve a more sustainable and resilient future for all. However, this requires urgent, ambitious and transformative action from all actors in all sectors and regions, guided by the best available science and informed by diverse perspectives and values.