Energy efficiency is one of the better ways to keep climate risks at bay, an International Energy Agency report released Wednesday from Italy said.

The IEA report finds as much as 40 percent of the reductions needed to keep global temperature increases at bay comes from energy efficiency.

"Energy efficiency is the invisible powerhouse in IEA countries and beyond, working behind the scenes to improve our energy security, lower our energy bills and move us closer to reaching our climate goals," IEA Executive Director Maria van der Hoeven said in a statement from Verona, Italy.

IEA's report said the global market of energy efficiency is worth at least $310 billion per year and should continue to grow. The Paris-based agency describes energy efficiency as the world's "first fuel."

The report finds energy consumption was down 5 percent from 2001-11 among 18 member states surveyed because of efficiency measures.

An IEA paper released last month suggests nearly 60 percent of the economic potential from energy efficiency is unrealized through 2035 because efficiency is typically undervalued in national policies.

"To fully expand this market, initiatives to continue to reduce barriers will need to strengthen," van der Hoeven said.