A major review of the Intergovernmental Panel on Climate Change’s fourth assessment report by the Netherlands Environment Agency wrapped up this week, finding no significant errors in the report’s main conclusions on regional impacts of climate change. It is the latest in a series of reviews that have largely validated mainstream climate science conclusions, while calling for further transparency in the working process.
The review was spurred by a Dutch media and political furore in February over an incorrect figure for the Netherlands’ area below sea level. This figure had been provided by the Dutch Environment Agency (PBL) to the IPCC and was published in the 2007 IPCC Assessment (AR4).
The exposure of the error came alongside a much-publicised mistake over the melting rate of Himalayan glaciers, and led the Dutch Minister of the Environment to call for a review into whether there were other errors in IPCC AR4’s section on regional impacts. The PBL has now released its findings and recommendations, which are summarised below.
The Netherlands Environment Agency (PBL) review found:
- No significant errors found in summary conclusions
- Provenance of summary statements needs to become more transparent in future reports
- The regional chapters contained one additional significant error (regarding a projected decrease in productivity of anchovy fisheries on the African west coast)
- Examples of negative impacts dominate at summary level
- No consequences for overarching conclusions
It also recommends that for future publications, the IPCC should:
- Create a public website for the submission of possible errors found in the published reports
- Provide stronger underpinning of generalisations of case studies to entire regions or sectors, also making use of regional modelling studies
- Ensure that statements that attribute impacts to climate change are well founded in scientific research, including systematic observations, modelling and statistics. The climate change component of impacts should be carefully characterised
- Be careful with phrasing of statements that could be perceived by readers as heightening the projected impacts of climate change
- IPCC governments should provide financial support for hiring chapter assistants to assist with quality control
- Assure that the reviews of all draft texts are fully covered by several expert reviewers
- Strengthen the expert and government reviews of the foundation for and provenance of statements in the summaries
- IPCC governments should increase their investments in climate-change observations and modelling in developing countries.
The full report can be downloaded here.