In October, amid dramatic reports of plane crashes and stranded migrants across Europe, the International Energy Agency (IEA) released a report keenly awaited by the environmental crowd — its Energy Efficiency Market Report 2015.

We are in an age of sharp attention on supply-and-demand fundamentals, and I have written before on the key role of energy efficiency as the "hidden fuel" in these calculations. In the foreword to the IEA's recent report, director Fatih Birol describes energy efficiency as the most important "arrow in the quiver" in the battle to decouple economic growth from greenhouse gas (GHG) emissions.

As I have already noted in the case of the U.S., Birol notes how the ongoing, steady improvement in energy efficiency over the past 40 years has gone largely unnoticed. Per capita energy consumption in IEA countries has now dropped to levels not seen since the 1980s, while income per capita has rocketed. Optimists will say citizens of these countries have had the best of both worlds — economic growth and efficiency gains — but this gradual decoupling is too rarely celebrated.

The report's significance is boosted, of course, by its timing just two months ahead of the United Nations climate summit in Paris. Negotiating governments will not, and cannot, allow progress on efficiency to relieve countries from their responsibilities to cut carbon consumption in more dramatic (and painful) ways, but the IEA report makes clear that it will have an important role.

The agency urges that energy efficiency savings must account for approximately 40 percent of emissions reductions required by 2050 in order to limit global temperature rises to the less than 2 degrees centigrade agreed in order to avoid "catastrophic" climactic impacts.

Reports of breakthroughs in energy-efficient innovation — from "Teslamania" to data-driven smart university campuses — often constitute the "good news" on climate change desks, amid otherwise gloomy images of failed promises, floods and heatwave victims. The authors of the IEA report talk of energy efficiency creating a "virtual supply" of energy, by reducing total final consumption (TFC) of energy across IEA countries by an amount larger than the annual TFC of Japan and Korea combined.

They estimate the global market for energy efficiency goods and services was worth $310 billion per year, which is why energy efficiency commitments are easier to stomach for governments. Indeed, if demanding targets are set in Paris, it could significantly boost the market for energy efficiency investments in efficient buildings, appliances and transportation. Tesla will be sitting pretty.

However, alongside the financial returns to citizens and governments, the report highlights strategic returns. Aside from the obvious implications for the global fight against climate change, there are dividends for energy security too as nations become less dependent on foreign sources of fossil fuel for their own economies. Germany, by avoiding imports, improved its trade surplus by an estimated 14 percent in 2014.

The IEA is optimistic about the potential impact of the low oil price environment on energy efficiency investments, provided there is strong policy making in consuming countries. While the financial appeal of energy efficiency policies is dimmer with oil at $50 a barrel, it also provides an opportunity to cut fuel subsidies with less pain to citizens. They are also banking on governments understanding the implications of their energy efficiency performance for energy security, productivity and local air pollution.

Which brings us to China. No discussion of energy consumption patterns can leave out China, which could reap multiple benefits from a growing energy efficiency market, driving both growth and wider social objectives.

The report notes that emerging economies are playing their part by at least "doing even more with more." During 2004-13, China improved its end-use energy productivity by 29 percent, even though its energy consumption rose by as much as 70 percent.

Birol's urge to "decouple" is particularly relevant for China, and statements by the Chinese government have been encouraging. The commitments are primarily aimed at shifting the country's energy mix away from coal (which currently accounts for almost two-thirds of the mix) through the introduction of "everything-but-coal" targets, but also includes explicit plans for low-carbon industrial systems ad emissions reductions through the built environment and transport.

Under China's INDCs (UN jargon for "intended nationally determined contributions"), it is expected that energy intensity in China will drop by around 57 percent by 2030.

Just like carbon-trading arrangements, energy efficiency components of climate change-avoidance strategies are more palatable to market liberals, who fear the impact of environmental policies on growth rates. The IEA estimates that member countries saved $80 billion in fossil fuel imports in 2014, nowhere more so than in Germany.

Few believe technology alone can help us avoid climate change disaster, but it will undoubtedly be a key talking point in Paris next month.