NEW YORK New York City's $170.6 billion pension system will analyze its carbon footprint for the first time amid concerns of potential investment risks from companies that fail to adapt to climate change, its custodian said in a statement on Thursday.

Trustees for the five funds that make up the system selected Mercer Investment Consulting LLC to determine how to incoporate "the realities of global warming" into asset allocation, manager selection and risk management, said New York City Comptroller Scott Stringer, custodian for the system.

Four of the funds - including for police and firefighters - also chose Trucost plc to perform a carbon footprint analysis of public equity investments.

That study involves measuring actual and estimated greenhouse gas emissions that can be attributed to an investment portfolio and, proportionally, to its holdings.

Mercer will conduct a carbon footprint analysis for the remaining fund, the Teachers Retirement System. The reviews are expected to be completed by the end of 2017.

The city's funds have previously taken other measures to address concerns about climate change and related investment risks, as have public pensions and other institutional investors around the world.

The $184.5 billion New York State Common Retirement Fund, the third largest in the country, last month became the first major U.S. public pension to join the Portfolio Decarbonization Coalition.

The coalition was co-founded by the United Nations' Environment Finance Initiative. Its 28 members control over $3 trillion of assets.

(Reporting by Hilary Russ)