How has the COVID-19 pandemic affected the climate change debate on Twitter?

•Concerns exist about the fact that over the past year, the pandemic has put on hold climate objectives.•We assess how the COVID-19 pandemic affected the climate change debate, while controlling for other factors.•Considered factors include socio-economic variables, social norms, and risk preferences.•We find that COVID-19 has reduced the amount of Tweets produced about climate change.•We find this reduction more significant in Spanish speaking countries. Climate change and the COVID-19 pandemic share many similarities. However, in the past months, concerns have increased about the fact the health emergency has put on hold during the pandemic many climate adaptation and mitigation policies. We focus our attention on understanding the role of the recent health emergency on the transmission of information related to climate change, jointly with other socio-economic variables, social norms, and cultural dimensions. In doing so, we create a unique dataset containing the number of tweets written with specific climate related keywords per country worldwide, as well as country specific socio-economic characteristics, relevant social norms, and cultural variables. We find that socio-economic variables, such as income, education, and other risk-related variables matter in the transmission of information about climate change and Twitter activity. We also find that the COVID-19 pandemic has significantly decreased the overall number of messages written about climate change, postponing the climate debate worldwide; but particularly in some vulnerable countries. This shows that in spite of the existing climate emergency, the current pandemic has had a detrimental effect over the short-term planning of climate policies in countries where climate action is urgent.