The "International Energy Outlook" projects that natural gas will be the world’s fastest growing fossil fuel in the period 2015 to 2040. In the United States, gas from shale will increase to nearly 70% of the nation’s natural gas production by 2040, with advances in horizontal drilling and hydraulic fracturing techniques. Pictured is natural gas fracking on the Haynesville Shale near Shreveport, La., in 2013. Credit: Daniel Foster, CC BY-NC-SA 2.0

Global energy consumption will increase 28% between 2015 and 2040, with fossil fuels still providing the bulk, 77%, of the energy consumption by 2040, according to a new report by the U.S. Department of Energy’s Energy Information Administration (EIA). That’s a slight tick down from EIA’s 2016 report that modeled fossil fuels as accounting for 78% of energy consumption by 2040.

The increased energy use will be matched by a 16% increase in energy-related carbon dioxide (CO2) emissions over that same time period, with annual emissions rising from 33.9 billion metric tons in 2015 to 39.3 billion metric tons in 2040, according to EIA’s report, “International Energy Outlook 2017,” released on Thursday. That energy usage, increasing from 575 quadrillion British thermal units (Btus) (607 exajoules) per year in 2015 to 663 quadrillion Btus (700 exajoules) in 2040, assumes an annual 1.7% gross domestic product growth in Organisation for Economic Co-operation and Development (OECD) countries—including the United States and many European nations—and a 3.8% growth in non-OECD countries.

The projected 16% increase in emissions noted in the new report differs significantly from the projected 34% increase stated in EIA’s 2016 report, which projected emissions rising from 32 billion metric tons in 2012 to 43 billion metric tons in 2040.

The new report, which provides long-term modeled projections of energy production and consumption, states that energy consumption could be up to 40 quadrillion Btus (42 exajoules) higher or 29 quadrillion Btus (31 exajoules) lower annually, depending on what rates of economic growth actually occur and other factors.

Reduction Expected in the Growth Rate of Emissions

The growth rate of energy-related CO2 emissions is expected to ease.

The growth rate of energy-related CO2 emissions is expected to ease, with an average 0.6% increase per year between 2015 and 2040, according to the report. That’s a sizeable drop from a 1.3% annual growth rate from 1990 to 2015. EIA attributes that anticipated slowdown to increases in energy efficiency and a gradual shift from coal to natural gas and renewable energy sources.

The report, which Ian Mead, EIA’s assistant administrator for energy analysis, presented at the briefing, also forecasts a 2.8% annual increase in renewable energy, including hydropower. “By 2040, generation from renewable energy sources surpasses generation from coal on a worldwide basis,” the report states.

EIA’s projections find renewables to be the most rapidly growing energy source for electricity generation. Still, the agency may be underestimating the contributions from renewables, according to some economists, including Rachel Cleetus, lead economist and climate policy manager for the Union of Concerned Scientists.

The report also forecasts a continued decrease in carbon intensity, the amount of energy used per unit of economic growth. EIA attributes that decrease to China’s decline in coal use and to global growth in the use of non-CO2-emitting sources of energy.

The industrial sector continues to account for the largest share of energy consumption through 2040, with a 0.7% annual increase in energy use between 2015 and 2040. However, other sectors grow faster, with energy use for the transportation and building sectors increasing 1% and 1.1% annually, respectively.

An Increase in Nuclear Power

Amid concerns about greenhouse gas emissions and energy security, nuclear power for electricity generation increases from 2.5 trillion kilowatt hours in 2015 to 3.7 trillion kilowatt hours in 2040, with much of that increased capacity in China, according to the report.

“Without pointing fingers at any particular countries, there are some regions where we don’t assume that [country targets for meeting Paris emissions goals are] a binding constraint.”

With the Paris accord on climate change having come into force in November 2016, EIA attempted to incorporate some details about country-specific plans to meet emissions targets. However, the report notes that a great deal of uncertainty remains about the full implementation of policies and how countries will meet their goals. It also mentions that the Paris accord covers more than energy-related CO2 emissions.

“Without pointing fingers at any particular countries, there are some regions where we don’t assume that [country targets are] a binding constraint,” Mead said at the briefing.

Fossil Fuels Continue to Dominate

The report projects that natural gas will be the world’s fastest growing fossil fuel, increasing by 1.4% annually, whereas petroleum and other liquids will increase 0.7% and coal will see just a 0.1% increase, with declined usage in China and OECD regions offset by growth in India and other non-OECD countries.

Fossil fuel dependence will continue because “a lot of it just has to do with the base that you are starting with,” Mead told Eos. “So it may take a while for some of those [other] sources to move in.”

—Randy Showstack (@RandyShowstack), Staff Writer

Correction, 9 November 2017: A prior version of this article omitted an decimal in an emissions projection. The error has been fixed.


Showstack, R. (2017), World’s heavy dependence on fossil fuels projected to continue, Eos, 98, Published on 18 September 2017.

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