Who participates in the Intergovernmental Panel on Climate Change and why: A quantitative assessment of the national representation of authors in the Intergovernmental Panel on Climate Change

► Europe and North America dominate participation in the IPCC (73%). ► 45% of countries have never contributed as authors in the Intergovernmental Panel on Climate Change process. ► Non-Annex 1 contributions, while improving, lag significantly behind Annex 1. ► Regression analysis shows that GDP, population, English language and tertiary education are significant drivers of national levels of authorship. ► Few authors, and limited expertise, may signify insufficient Non-Annex 1 capacity. This paper presents a quantitative analysis of international representation in the activities of the Intergovernmental Panel on Climate Change using expert authorship counts by country in each of the four IPCC assessment reports (1990, 1995, 2001 and 2007). Overall, we find that 45% of countries, all Non-Annex 1, have never had authors participate in the IPCC process; on the other hand, European and North American experts are make up more than 75% of all authors ( N = 4394). Generalized linear models using negative binomial regression were used to quantitatively estimate the effect of a number of socio-economic, environmental and procedural factors influencing country-level participation in the IPCC. Per capita gross domestic product, population, English-speaking status, and levels of tertiary education were all found to be statistically significant drivers of authorship counts. In particular, participation by authors from English-speaking Non-Annex 1 countries is 2.5 times greater than those that are non-English speaking. Regionally small island nations of Oceania were the most severely under-represented group. South American and Asian countries had fewer authors, and African countries had more authors than what might be expected on the basis of demographic and socio-economic data. These differences across nations partly reflect existing scientific capacity that will be slow to change. However, the on-going under-representation of developing country scientists in the IPCC, particularly in the assessment of climate science (WGI) and climate mitigation (WGIII) warrants greater efforts to close the capacity gap.