Renewable sources will be the leading source of electricity by 2030, an International Energy Agency report to be released Monday predicts. The report also says greenhouse gas emissions could peak as early as 2020 using existing technology with no net economic cost.

The IEA's report, "Energy and Climate Change," says if the world sets conditions to achieve emissions-related goals, reviews national climate targets regularly, translates climate goals to long-term emissions goals and tracks the transitions, emissions can begin falling as early as 2020.

The report said though electricity from renewable sources like solar and wind will be the leading source of electricity by 2030, inefficient coal-fired power generation will fall only slightly, underlining the need for ambitious pledges by leading nations.

Assuming renewable sources will not impact today's energy companies would be a mistake, IEA chief economist Fatih Birol told the Financial Times. “That would be like assuming interest rates will stay the same for the next 25 years,” he said in an interview. “It’s the same type of short-sightedness.”

The IEA urged governments to require industry, buildings and the transport sector to increase energy efficiency, reduce the use of coal and ban the construction of new coal-fired plants, increase investment in renewable energy from $270 billion in 2014 to $400 billion by 2030, phase out use of fossil-fuel subsidies by 2030, and reduce methane emissions in oil and gas production.

"As IEA analysis has repeatedly shown that the cost and difficulty of mitigating greenhouse-gas emissions increases every year. Time is of the essence," IEA Executive Director Maria van der Hoeven said. "It is clear that the energy sector must play a critical role if efforts to reduce emissions are to succeed. While we see growing consensus among countries that it is time to act, we must ensure that the steps taken are adequate and that the commitments made are kept."

The report said governments should make climate pledges for December's 21st U.N. Conference of the Parties, known as COP21, to serve as a basis for further progress and recommends setting a goal of keeping the long-term average increase in global temperatures to less than 2 degrees Celsius.

“Any climate agreement reached at COP21 must have the energy sector at its core or risk being judged a failure,” Birol said. “Climate pledges submitted for COP21 are an important first step to meeting our climate goal, and our report shows that they will have a material impact on future energy trends.”

The IEA said pledges that have been made so far fall short of the 2-degree Celsius goal, but the proposals do show a weakening link between economic growth and carbon dioxide emissions.