What is the IPCC?
The Intergovernmental Panel on Climate Change is a UN body set up in 1988 to assess the science around climate change. The IPCC provides governments with scientific information they can use to develop policies on global heating.
The first of its comprehensive Assessment Reports on climate change was released in 1992. The sixth in this series will be split into four volumes, the first of which - covering the physical science behind climate change - will be published today. Further parts of the review will cover impacts and solutions. A summary has been approved in a process involving scientists and representatives of 195 governments.
Humanity's damaging impact on the climate is a "statement of fact", say UN scientists in a landmark study.
The report says that ongoing emissions of warming gases could also see a key temperature limit broken in just over a decade. The authors also show that a rise in sea levels approaching 2m by the end of this century "cannot be ruled out".
But there is new hope that deep cuts in emissions of greenhouse gases could stabilise rising temperatures. This sober assessment from the Intergovernmental Panel on Climate Change (IPCC) features in a 42-page document known as the Summary for Policymakers.
It leads a series of reports that will be published over coming months and is the first major review of the science of climate change since 2013. Its release comes less than three months before a key climate summit in Glasgow known as COP26.
"Today's IPCC Working Group 1 Report is a code red for humanity," said UN Secretary-General, António Guterres.
"If we combine forces now, we can avert climate catastrophe. But, as today's report makes clear, there is no time for delay and no room for excuses. I count on government leaders and all stakeholders to ensure COP26 is a success."
"it is unequivocal that human influence has warmed the atmosphere, oceans and land".
The Summary for Policymakers of the Working Group I contribution to the Sixth Assessment Report (AR6) as well as additional materials and information are available at IPCC Climate Change Report
Every region facing increasing changes
Many characteristics of climate change directly depend on the level of global warming, but what people experience is often very different to the global average. For example, warming over land is larger than the global average, and it is more than twice as high in the Arctic.
“Climate change is already affecting every region on Earth, in multiple ways. The changes we experience will increase with additional warming,” said IPCC Working Group I Co-Chair Panmao Zhai.
The report projects that in the coming decades climate changes will increase in all regions. For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.
But it is not just about temperature. Climate change is bringing multiple different changes in different regions – which will all increase with further warming. These include changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans. For example:
- Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions.
- Climate change is affecting rainfall patterns. In high latitudes, precipitation is likely to increase, while it is projected to decrease over large parts of the subtropics. Changes to monsoon precipitation are expected, which will vary by region.
- Coastal areas will see continued sea level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion. Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
- Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice.
- Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century.
- For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea level rise in coastal cities.
For the first time, the Sixth Assessment Report provides a more detailed regional assessment of climate change, including a focus on useful information that can inform risk assessment, adaptation, and other decision-making, and a new framework that helps translate physical changes in the climate – heat, cold, rain, drought, snow, wind, coastal flooding and more – into what they mean for society and ecosystems.
This regional information can be explored in detail in the newly developed Interactive Atlas interactive-atlas.ipcc.ch as well as regional fact sheets, the technical summary, and underlying report.
IPCC report fast facts
- Global surface temperature was 1.09C higher in the decade between 2011-2020 than between 1850-1900.
- The past five years have been the hottest on record since 1850
- The recent rate of sea level rise has nearly tripled compared with 1901-1971
- Human influence is "very likely" (90%) the main driver of the global retreat of glaciers since the 1990s and the decrease in Arctic sea-ice
- It is "virtually certain" that hot extremes including heatwaves have become more frequent and more intense since the 1950s, while cold events have become less frequent and less severe
Photo by Kelly Sikkema, Callum Shaw and Julia Joppien