Institutional investor groups representing more than $20tn in assets under management issued a joint statement on Thursday calling on companies and governments to take action to minimize methane emissions from "fracking."

Hydraulic fracturing, or fracking, is used to extract shale gas, but a surge in its production has been accompanied by growing environmental concerns, including about the negative effect on the world’s climate of methane released during the fracking process.

The statement said group members were concerned about regulatory and reputational risk associated with so-called “fugitive methane” and the significant climate change concerns that methane emissions raise.

It said the groups were working with industry and experts, in co-ordination with the Carbon Disclosure Project, to develop an investor framework for disclosure to evaluate company progress on reducing methane emissions.

Consultation on the draft disclosure framework is currently underway, with a final version due for publication in October 2012.