The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the most recent scientific research on climate change. The IPCC is widely acknowledged as the most reliable source of advice on climate change. The IPCC reviews the most recent scientific, technical and socio-economic research produced worldwide relevant to the understanding of climate change.
Fifth Assessment Report
The IPCC publishes Assessment Reports every six to seven years, with the IPCC First Assessment report published in 1990. The Fifth Assessment Report is being published in stages across 2013 and 2014. The Working Group I report, The Physical Science Basis, was released on 27 September 2013. The report finds that there is strong evidence that the Earth’s climate system is changing, and there is now stronger evidence than ever that human activities are the primary cause.
Other key findings include:
- There is robust evidence that multiple components of the Earth’s climate system are changing, including rising global air and ocean temperatures, widespread melting of snow and ice, rising global average sea level, and changes in many extreme events.
- For the first time, the IPCC provides estimates of the total allowable global emissions of carbon in order to limit temperature rise to 2°C above pre-industrial levels.
- The likely total allowable global emissions are about 1,000 billion tonnes of carbon. By 2011, around half of this budget had already been emitted.
- If emissions of greenhouse gases other than carbon dioxide (eg. methane and nitrous oxide) are accounted for, the likely allowable emissions are reduced to about 790 billion tonnes of carbon
- If emissions continue to track at the top of IPCC scenarios, global temperature could rise by between 3.2°C and 5.4°C by the end of the century (relative to a 1850-1900 baseline). If emissions track along the lowest scenario, then global average temperature could rise from 0.9-2.3°C by the end of the century (relative to a 1850 -1900 baseline).
- We are already observing the consequences of a changing climate in Australia and elsewhere around the world.
- Scientific understanding of sea level rise has improved and projections of global average sea level rise are higher than in previous IPCC reports.
The report represents the international consensus on climate change science in literature that has been extensively peer-reviewed and published in scientific journals. The report is available from the Intergovernmental Panel on Climate Change.
Further information about the Fifth Assessment Report.
Special Report on Extreme Events
In 2012 the IPCC released the Special Report for Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX report) which brings together the latest research on climate change and extreme events.
Key findings from the SREX report include:
- It is virtually certain that the world will experience a decrease in cold extremes and an increase in the frequency and magnitude of warm extremes over the 21st century.
- It is very likely that mean sea level rise will contribute to upward trends in extreme sea levels in the future.
- It is likely that the frequency of heavy precipitation will increase over many areas of the globe.
- Key findings from the SREX report for Australia include:
- Australia has already observed an increase in warm days and a decrease in cold days. This trend is projected to continue with large scale increases in the number of days over 35 degrees Celsius and 40 degrees Celsius and an increase in heatwave duration.
- Extreme rainfall events are projected to increase.
- Tropical cyclones are likely to become more intense and shift southwards; however the frequency of tropical cyclones could remain unchanged or even decrease.
- Since the 1950s there has been an observed increase in drought over the south west and south east of Australia with projections indicating this could continue.
- In south-east Australia, the frequency of very high and extreme fire danger days is expected to rise by 15-70 per cent by 2050. The fire season is expected to lengthen.
The most effective adaptation and disaster risk reduction actions for extreme events are those that offer development benefits in the relatively near term, as well as reductions in vulnerability over the longer term.
- Intergovernmental Panel on Climate Change facts
- Intergovernmental Panel on Climate Change website
- Special Report for Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX report)