Report at a glance
- Full official title
- Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change
- Publisher
- Intergovernmental Panel on Climate Change (IPCC)
- Date published
- 20 March 2023
- Length
- 184 pages in the publisher’s citation; 186 PDF pages including covers
- Original source
- Official report page · Original PDF
- Topics covered
- Global climate, Heat, Water and floods, Finance
The answer in 3 sentences
What does the IPCC AR6 Synthesis Report say about climate change?
The IPCC AR6 Synthesis Report, Climate Change 2023, answers the question "What does the IPCC say about climate change?" by finding that human activities have unequivocally caused global warming. It finds that risks grow with each further increment of warming and that the people who contributed least are often affected most. Deep emissions cuts and faster adaptation can limit future harm, with benefits for health and air quality.
Key findings
- Human activities have unequivocally caused global warming, mainly through greenhouse gas emissions. The headline observed global warming level was 1.1°C in 2011 to 2020 relative to 1850 to 1900. (IPCC AR6 Synthesis Report, 2023; p. 4; SPM A.1)
- Human-caused climate change is already affecting weather and climate extremes in every region, with widespread losses and damages (high confidence). (IPCC AR6 Synthesis Report, 2023; p. 5; SPM A.2)
- Vulnerable communities that historically contributed least to climate change are disproportionately affected (high confidence). (IPCC AR6 Synthesis Report, 2023; p. 5; SPM A.2)
- Increased extreme heat has caused deaths and illness in every region (very high confidence). (IPCC AR6 Synthesis Report, 2023; p. 6; SPM A.2.5)
- Every increment of warming intensifies multiple hazards (high confidence). Deep, rapid and sustained emissions cuts would slow warming. (IPCC AR6 Synthesis Report, 2023; p. 12; SPM B.1)
- Limiting human-caused warming requires net zero carbon dioxide emissions, alongside strong reductions in other greenhouse gases (high confidence). (IPCC AR6 Synthesis Report, 2023; p. 19; SPM B.5)
- Faster emissions cuts and adaptation reduce future losses and damages (very high confidence) and offer air quality and health benefits (high confidence). (IPCC AR6 Synthesis Report, 2023; p. 25; SPM C.2)
- Improved access to finance can help developing countries adapt and reduce emissions (high confidence). (IPCC AR6 Synthesis Report, 2023; p. 33; SPM C.7.2-C.7.4)
Key numbers
| Figure | What it measures | Year or period | Original page |
|---|---|---|---|
| 1.09°C (0.95 to 1.20°C) | Observed global surface temperature increase relative to 1850 to 1900; bracket is the very likely range | 2011 to 2020 | 4 |
| 59 ± 6.6 GtCO₂-eq | Global net anthropogenic greenhouse gas emissions | 2019 | 4 |
| 0.20 m (0.15 to 0.25 m) | Observed global mean sea-level increase; very likely range | 1901 to 2018 | 5 |
| 3.3 to 3.6 billion | People living in contexts highly vulnerable to climate change (high confidence) | Assessed in 2023 | 5 |
| 15 times | Flood, drought and storm mortality in highly vulnerable regions compared with regions of very low vulnerability (high confidence) | 2010 to 2020 | 5 |
| 43% (34 to 60%) | Median global GHG reduction from 2019 in pathways limiting warming to 1.5°C with over 50% likelihood and no or limited overshoot; range is pathway 5th-95th percentile | 2030 (scenario) | 21 |
Source: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (2023). Page numbers above use the printed report, unless a PDF page is explicitly named.
What it means for Pakistan and the Global South
The synthesis identifies South Asia as a hotspot of high human vulnerability (high confidence, p. 51, section 2.1.2). It links vulnerability to poverty, governance challenges and limited access to basic services, and finds that finance gaps are largest in developing countries (high confidence, p. 33, C.7.4). These are regional and development findings. The headline warming, emissions and sea-level numbers above are global and must not be described as measurements for Pakistan.
What the report does not say
- This is an assessment of published science, not a weather forecast or a new set of local measurements.
- Its global averages do not describe the temperature or flood risk of an individual place in Pakistan.
- Modelled pathways are conditional projections, not predictions or fixed national emissions quotas (p. 9, Box SPM.1).
- Net zero carbon dioxide does not mean that every greenhouse gas emission has ended; residual emissions and removals are treated separately (pp. 20-21).
How to cite this report
Please cite the original report, not this summary.
APA 7
Intergovernmental Panel on Climate Change. (2023). Climate change 2023: Synthesis report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (Core Writing Team, H. Lee, & J. Romero, Eds.). https://doi.org/10.59327/IPCC/AR6-9789291691647
Harvard
IPCC (2023) Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by Core Writing Team, H. Lee and J. Romero. Geneva: IPCC. doi:10.59327/IPCC/AR6-9789291691647.