Ratan Tata-led Tata group companies are targetting a 20-50% emission reduction in 10-30 years.
The group, which began carbon footprint measurement of group companies in 2008, will bring all its 76 companies under the GHG Protocol Corporate Accounting and Reporting Standard, an emission calculating methodology, this year.
Tata Steel, Tata Power, Tata Chemicals and Tata Motors - which together account for 80% of the carbon emission of the group - have set different emission reduction targets.
Tata Steel has taken up ultra-low CO2 steelmaking project (ULCOS), through which it aims to achieve 50% reduction in carbon emissions by 2050.
Tata Chemical has set a target of 20% reduction in green house gas emissions by 2020. As part of shifting to a "carbon-conscious" manufacturing practice, the company has stopped producing methyl bromide and consuming carbon tetra chloride and freon-12 (generally known as ozone depleting substance).
Tata Motors is targetting a 5% year-on-year reduction in the generation of CO2 emissions from manufacturing.
The carbon footprint of all group companies will be measured by the year-end. "We began the carbon footprint measurement of all group companies in June 2008," said Prasad Menon, director, Tata Industries. "Most of the 76 firms, which together account for 98% of the group's carbon emission are already covered. Some small companies are remaining. They will be covered this year."