Citigroup will be tougher on clients in the oil-and-gas industry, changing the way the bank asks Big Oil to measure how much pollution their efforts spew into the air as a requirement for receiving financing while the world tries to curb global warming.

Citi said in a 19 January report that it aims for an “absolute reduction” in emissions from companies across its energy loan portfolio of 29% by 2030 from 2020. Citi did stress that dropping oil and gas clients if they are deemed to fall short of such targets would only be a last resort.