A global effort to deploy the right energy efficiency policies could, on its own, see greenhouse gas emissions peak quickly and then fall even as the global economy doubles between now and 2040.

Energy demand, energy intensity, and GDP. Image courtesy of OECD/IEA.
That is one of the conclusions of Energy Efficiency 2018, a report from the International Energy Agency.
The report examines the opportunities for improving global energy efficiency to 2040, and finds that efficiency gains alone could allow the world to extract twice as much economic value from the energy it uses compared to today. Doing so would reduce energy bills for consumers by more than $500 billion dollars per year, lower energy imports and cut air pollution in cities – a key issue for many countries.
Per the report, industry could produce nearly twice as much value per unit of energy by 2040 through efficiency improvements. However, to realize these opportunities, average annual energy efficiency investment would need to double to 2025 and then double again to 2040. Per the report, all the needed investment opportunities are highly cost-effective and would bring significant economic benefits.