The UK's 2050 net-zero emission target is one of the most ambitious goals in the world. Organisations should play a vital role by communicating a sufficient level of carbon emission information with the stakeholders. Motivated by the necessity of measuring the level of carbon disclosure, this paper provides a unique carbon emission disclosure measurement based on a sample of UK firms from 2013 to 2019. We apply different methods to assess the validity and reliability of our developed measurement. The results suggest that our measurement captures the actual CO2 emission, including scope 1, scope 2, and also captures the environmental, social and governance (ESG) score. Additionally, we explore the association between capital expenditure, corporate governance and the level of carbon emission disclosure. Further, the results show a positive relationship between capital expenditure and carbon emission disclosure. Also, there is a significant positive relationship between internal governance and carbon emission disclosure. Moreover, the analysis suggests that internal governance strengthen the relationship between capital expenditure and carbon emission disclosure. We also use quantile regression, and the findings show that capital expenditure and internal governance have a positive impact on carbon emission disclosure under all quantiles. Our data suggest that capital expenditure declines within the UK by around 53% over the last six years. Following the reduction in capital expenditure, the results demonstrate 39% decline in the CO2 emission level. The results also indicate that for every $1 million capital expenditure, approximately 2.75 Metric tons of carbon dioxide (MtCO2) emissions increase. Business investment is around 70% of the UK's total investment. Therefore, the reduction in capital expenditure is one of the primary reasons that might explain the decrease in the UK's overall CO2 emission level. The unique findings of this paper are relevant to the government, management and standard-setters.