India's CO2 emissions have fallen for the first time in four decades, according to researchers at the Centre for Research on Energy and Clean Air (CREA).

This happened due to an economic slowdown, growth of clean energy and the ongoing lockdown. It was revealed in the latest analysis done by Lauri Myllyvirta and Sunil Dahiya at CREA.

"Emissions fell by around 1 percent in the fiscal year ending March 2020, as coal consumption fell and oil consumption flatlined," said the researchers.

Falling electricity use and competition from renewables had weakened the demand for fossil fuels even before the coronavirus hit, according to the analysis. However, it was the sudden nationwide lockdown in March that further pushed the emissions growth trend into reverse.

The study finds that Indian carbon dioxide emissions fell 15% in March, and are likely to have fallen by 30% in April.

The researchers looked further into the sectors that has contributed most towards the decline:

Coal: Coal-fired power generation was down 15% in March and 31% in the first three weeks of April. Even before India's sudden coronavirus lockdown, the demand for coal was weakening.

The study finds that in the fiscal year ending March 2020, coal deliveries were down by around 2%, a small but significant reduction when set against the trend - an increase in thermal power generation of 7.5% a year set over the previous decade.

Oil: Indian oil consumption shows a similar reduction in demand growth. Oil consumption was down 18% year-on-year in March 2020.

Consumption during the fiscal year only grew 0.2 percent -- the slowest in 22 years, on the back of slow demand growth earlier in the year and a dip in demand during the lockdown.

The researchers stated that taking the above figures in mind they have estimated that CO2 emissions fell by 30 million tonnes in the fiscal year ending March -- the first annual decline in four decades.

As for the dip in carbon emissions in April, the researchers said that the estimates are based on power-sector emissions from daily generation data. They said that they have assumed that consumption fell as much in April as in March, which is a conservative estimate as the lockdown was in full force till the end of the month.