November 5, 2015

Global Concern about Climate Change, Broad Support for Limiting Emissions

Appendix

Brazil Most Concerned, Israel LeastTo explore the relationship between climate change and other objective economic and environmental indicators, we developed an additive climate change concern index. The index combines responses for three survey questions that ask about the extent to which people believe global climate change is a serious problem, is harming people now and will impact them personally at some point in their lives. The index was developed using a principle components analysis and alpha reliability coefficients.

Responses for each of the three questions range between 1 and 4, where 1 indicates the least concerned about climate change and its impact and 4 is the most concerned. For instance, those who believe climate change is a very serious problem are coded as a 4 while those who say that climate change is not at all a problem are coded as a 1. The responses for the three questions are added together for an index range from 3 to 12, where 3 is the least concerned about climate change and 12 is the most concerned.

Index scores are only calculated for respondents who gave substantive answers to all three questions, comprising a large sub-sample of the total sample (n=42,136). Those who replied “Don’t know/Refused” were not included in the index.

We report the mean score for each country in our analysis. On a scale of 3 to 12, index scores range between 8.66 in Israel and 11.42 in Brazil, with an overall average of 9.93 for all valid responses.