Links in the chain: Global carbon emissions and consumption

Washington, D.C. — It is difficult to measure accurately each nation’s contribution of carbon dioxide to the Earth’s atmosphere. Carbon is extracted out of the ground as coal, gas, and oil, and these fuels are often exported to other countries where they are burned to generate the energy that is used to make products. In turn, these products may be traded to still other countries where they are consumed. A team led by Carnegie’s Steven Davis, and including Ken Caldeira, tracked and quantified this supply chain of global carbon dioxide emissions. Their work was published online by Proceedings of the National Academy of Sciences during the week of October 17.

The Supply Chain of CO2 Emissions

See “The supply chain of CO2 emissions“, doi: 10.1073/pnas.1107409108 PNAS October 17, 2011

Traditionally, the carbon dioxide emitted by burning fossil fuels is attributed to the country where the fuels were burned. But until now, there has not yet been a full accounting of emissions taking into consideration the entire supply chain, from where fuels originate all the way to where products made using the fuels are ultimately consumed.

“Policies seeking to regulate emissions will affect not only the parties burning fuels but also those who extract fuels and consume products. No emissions exist in isolation, and everyone along the supply chain benefits from carbon-based fuels,” Davis said.

He and Caldeira, along with Glen Peters from the Center for International Climate and Environmental Research in Oslo, Norway, based their analysis on fossil energy resources of coal, oil, natural gas, and secondary fuels traded among 58 industrial sectors and 112 countries in 2004.

They found that fossil resources are highly concentrated and that the majority of fuel that is exported winds up in developed countries. Most of the countries that import a lot of fossil fuels also tend to import a lot of products. China is a notable exception to this trend.

Davis and Caldeira say that their results show that enacting carbon pricing mechanisms at the point of extraction could be efficient and avoid the relocation of industries that could result from regulation at the point of combustion. Manufacturing of goods may shift from one country to another, but fossil fuel resources are geographically fixed.

They found that regulating the fossil fuels extracted in China, the US, the Middle East, Russia, Canada, Australia, India, and Norway would cover 67% of global carbon dioxide emissions. The incentive to participate would be the threat of missing out on revenues from carbon-linked tariffs imposed further down the supply chain.

Incorporating gross domestic product into these analyses highlights which countries’ economies are most reliant on domestic resources of fossil energy and which economies are most dependent on traded fuels.

“The country of extraction gets to sell their products and earn foreign exchange. The country of production gets to buy less-expensive fuels and therefore sell less-expensive products. The country of consumption gets to buy products at lower cost.” Caldeira said. “However, we all have an interest in preventing the climate risk that the use of these fuels entails. [Emphasis is mine]

To look at the data, visit:

The Department of Global Ecology was established in 2002 to help build the scientific foundations for a sustainable future. The department is located on the campus of Stanford University, but is an independent research organization funded by the Carnegie Institution. Its scientists conduct basic research on a wide range of large-scale environmental issues, including climate change, ocean acidification, biological invasions, and changes in biodiversity.

The Carnegie Institution for Science ( is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

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2 Responses to Links in the chain: Global carbon emissions and consumption

  1. Alan Burke says:

    Here’s the abstract for the PNAS study: The supply chain of CO2 emissions. The full text of the study with accompanying supplemental data can be downloaded in PDF form from here.


    CO2 emissions from the burning of fossil fuels are conventionally attributed to the country where the emissions are produced (i.e., where the fuels are burned). However, these production-based accounts represent a single point in the value chain of fossil fuels, which may have been extracted elsewhere and may be used to provide goods or services to consumers elsewhere.

    We present a consistent set of carbon inventories that spans the full supply chain of global CO2 emissions, finding that 10.2 billion tons CO2 or 37% of global emissions are from fossil fuels traded internationally and an additional 6.4 billion tons CO2 or 23% of global emissions are embodied in traded goods.

    Our results reveal vulnerabilities and benefits related to current patterns of energy use that are relevant to climate and energy policy. In particular, if a consistent and unavoidable price were imposed on CO2 emissions somewhere along the supply chain, then all of the parties along the supply chain would seek to impose that price to generate revenue from taxes collected or permits sold.

    The geographical concentration of carbon-based fuels and relatively small number of parties involved in extracting and refining those fuels suggest that regulation at the wellhead, mine mouth, or refinery might minimize transaction costs as well as opportunities for leakage.

  2. Alan Burke says:

    From the Guardian, Duncan Clark Friday 21 October 2011:
    Groundbreaking data tracks carbon emissions back to their source
    A new scientific paper allows us to see which countries extracted the fossil fuels burned to support lifestyles in other countries

    Overview of carbon flows from fossil fuel extraction to the final consumers of goods and services

    Which of the following accounts for the largest share of the UK’s carbon footprint? All our holiday flights, all the power used in our homes or … Russia?

    Okay, so it’s kind of a trick question, but according to a scientific paper published this week, we might reasonably conclude that the answer is Russia – though to understand why it’s necessary to go back a couple of steps.

    More (Click here)

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