Response: the IPCC
The Intergovernmental Panel on Climate Change : IPCC
- In 1988 the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) established the IPCC to provide governments and policymakers around the world with regular scientific assessments about climate change.
- The reports include scenarios: what our futures might be like depending on how much more warming we cause.
- The first part of the Sixth Assessment Report, Climate Change 2021: The Physical Science Basis was finalized on 6 August 2021 during the 14th Session of Working Group I and 54th Session of the IPCC (Video 1).
“Climate change is widespread, rapid, and intensifying… Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years.” – IPCC Press Release 09 August 2021
Once it became clear that the world’s climate was changing, it was also evident that every aspect of life on Earth would be affected. The IPCC was formed to gather research from around the world, evaluate it, and use it to make predications about the impacts, with the objective of ‘stablising greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (human-induced) interference with the climate system’.
By gathering research from across all sectors, the IPCC is also able to see where there are gaps in knowledge, which in turn to direct research.
Each of the six Assessment Reports published since 1988 runs into several million words, are in several parts, and were collated over four to five years by scientists and researchers nominated by their respective governments (Fig. 1). This process ensures that:
- All member nations are represented
- There is time to include all relevant material
- A consensus is reached by all nations prior to each Assessment Report being released
Thousands of scientists and other experts around the world volunteer their time to write and review the draft reports. As these are long and technical to ensure the research is robust and comprehensive, there is also a summary report for policymakers. Delegates from all participating governments—around 120 including New Zealand—check the summary report line-by-line, and all countries have to agree on the wording before the final report is published.
The Sixth Assessment Report now underway. The first report in this cycle, the Physical Science, is now published. The second report ‘Mitigation’ and third report ‘Impacts, Adaptation and Vulnerability’ will be published in 2022.
Criticisms of past reports being too conservative
Some assumptions in earlier reports have not (so far) come to pass; primarily:
- Once governments knew the problems that climate change would bring, they would act quickly to replace fossil fuels. This is slowly happening, but not anywhere fast enough, and not by all governments.
- Technologies would be invented and installed to remove excess greenhouse gasses from the atmosphere. This technology exists, but is not cost effective.
Some nations rejected aspects of the science and implications of climate change, insisting on language in the summary reports that downplayed the scale and urgency of the problems.
It takes time, sometimes years to gather robust evidence, write research papers, and have that research published. Some research included in the IPCC may be more than a decade old, so by the time IPCC reports are released, information may already be superseded. For example, the 2001 Third Assessment Report included predictions about sea level rise and temperatures with the ‘worst case’ scenario regarded as ‘least likely’. On the eve of the Fourth Assessment Report in 2007, a study was published showing the temperatures were at the top end of the worst predictions, and sea levels were rising much faster (Fig. 2).
Most recent reports
The Fifth Assessment Report, which superseded earlier reports, was used as the basis of the Paris Agreement to keep global temperatures under 1.5°C. Interim reports focused on specific issues took into account more recent observations and research:
- October 2018: Global Warming of 1.5°C (SR15) made it abundantly clear that temperatures needed to be kept under 1.5°C, not 2.0°C in order to ‘avoid the worst effects of climate change’.
- May 2019: The 2009 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (used by MfE to account for NZ’s greenhouse gas emissions).
- August 2019: Climate Change and Land (SRCCL)
- September 2019: Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC)
The Sixth Assessment Report, Climate Change 2021: The Physical Science Basis, was finalized on 6 August 2021. This includes and interactive map (Fig. 3) and an unequivocal warning: the science is indisputable.
References and further reading
- IPCC website (links to all prior reports)
- 2021 (August) Sixth Assessment Climate Change 2021: The Physical Science Basis, Working Group I contribution
- Interactive mapping tool
- 2007: Rhamstorf et al; Recent Climate Observations Compared to Projections Science 316(5825) :709