Land-cover changes occurring before 1800 are often ignored in the estimation of CO2 emissions, probably because they are poorly documented in most tropical countries. India appears to be an exception to this rule. It was possible to reconstitute the main stages of the land-cover history for a large region of South India, and therefore to retrace the dynamics of CO2 emissions during nearly 1000 years. It was then possible to demonstrate that 25% of the total emissions occurred before 1800, and are mistakenly considered as more recent emissions.