The Investor Group on Climate Change (IGCC) has urged parliament to pass the carbon pollution reduction scheme (CPRS).

The CPRS includes the emissions trading scheme (ETS), which prices carbon.

"Investors need to be able to include carbon risk in their investment decisions and the passage of the CPRS would allow this for the first time in Australia," IGCC chief executive Nathan Fabian said.

"Delaying passage of the scheme yet again will hold up investment decisions and generate significant uncertainty in the business and investment sectors."

Fabian said there was a need to price carbon if the market was to respond.

"If we don't have a CPRS we don't have a price on carbon and this makes it hard for investors to respond to the market," he said.

The IGCC, however, did not support some of the CPRS amended provisions, particularly concessions given to the agricultural sector, he said.

"Concessions given to some sectors disadvantage other sectors of the economy. This is a drawback for our investors as they invest in the whole economy," he said.

Despite the shortcomings of the existing CPRS, he said the group would work with the current design.

"No scheme will be perfect in the first instance, but it is time to get on with the job of reducing emissions," he said.

The IGCC represents institutional investors that collectively manage more than $500 billion in funds under management. Investors include industry superannuation funds and fund managers.