The sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC), Climate Change 2021 – The Physical Science Basis, was released on Monday, August 9, 2021.
The Intergovernmental Panel on Climate Change is the United Nations body responsible for assessing the science related to climate change.
Several hundred scientists from around the world have contributed to this report, which provides an assessment and synthesis of the peer-reviewed literature on climate science.
Five scientists from CSIRO were part of the 14-person Australian author group.
It includes information on the rates, causes and likely future trajectories of global warming and other changes in the climate system.
What are the conclusions of the report?
The report provides information on climate change around the world. It contains more regional information than any previous IPCC assessment.
The report’s synthesis document (known as the Summary for Policymakers) synthesizes the global findings into 14 high-level statements in four areas:
- The current state of the climate
- Our possible climatic futures
- Climate information for risk assessment and regional adaptation
- Limit climate change.
Global findings relevant to Australia include:
- Large-scale indicators of climate change in the atmosphere, ocean and cryosphere are rising and changing at rates not seen for centuries or thousands of years.
- It is virtually certain that the frequency and intensity of extreme heat as well as the intensity and duration of heat waves have increased in most parts of the world since 1950.
- Marine heat waves have become more frequent in the 20th century, human influence has most likely contributed to 84-90% of them since at least 2006.
- The frequency and intensity of heavy precipitation events have increased in most land areas with good observational coverage, and human influence is probably the main factor behind this increase.
- Human influence has contributed to drought especially during the dry season on most land due to increased demand for atmospheric evaporation.
Regional fact sheets have been produced by the IPCC, including a fact sheet on the Australasian region.
The IPCC findings for the Australian region are consistent with the State of the Climate 2020 report published by CSIRO and the Bureau of Meteorology.
How did CSIRO contribute to the IPCC report?
Five scientists from CSIRO participated in the writing and writing of the report.
They have contributed to areas such as global carbon cycles, oceans and sea level change, climate change projections and regional impacts of climate change.
Specifically, this relates to the Atlas of Global and Regional Climate Projections and Chapters 5, 9 and 12.
Science peer reviewed by CSIRO scientists was also considered within the scope of the report.
CSIRO scientists are contributing other parts of the IPCC Sixth Assessment Report, including the volume on Impacts, Adaptation and Vulnerability, which is currently scheduled for publication in February 2022.
CSIRO scientists work closely with research and academic partners to provide climate, ocean and atmosphere research to a large community of end users across many sectors of Australian industry and government. . Learn more about CSIRO’s research on climate change.
Where can I access Climate Change 2021: The Basics of Physical Science?
The full report, Summary for Policymakers document, regional fact sheets and other resources are available at https://www.ipcc.ch/assessment-report/ar6/