In this article, we examine the rates, disclosure regimes and levels of corporate carbon emissions in the major European stock market indices from 2002 to 2017. We find an increase in the rate of disclosure and a decrease in the level of carbon emissions. The decrease in the level of carbon emissions is mainly due to the decrease in emissions from companies belonging to the FTSE 100 and the CAC 40 - two indices in which companies are subject to mandatory disclosure. For companies belonging to other stock market indices - which are generally subject to less prescriptive disclosure regimes - carbon emissions decrease slightly or increase. Finally, we show that the relationship between disclosure rates and carbon emissions levels is negative : within an index, the higher the number of companies disclosing their carbon emissions, the lower the average carbon emissions.