Atmospheric Sciences News

Targets of Biggest Global Carbon Emitters Flunk Fairness Test

Pledges so far by the United States, European Union, and China would require all other countries to emit 7 to 14 times less per capita than those three regions by 2030 to limit warming to 2°C.


In a new study, researchers have analyzed how much countries worldwide say they’ll cut greenhouse gas emissions, finding that the pledges of the biggest emitters—the European Union (EU), United States, and China—don’t meet widely held standards for international fairness. Unless those top three emitters commit to steeper reductions in their use of fossil fuels and invest in technology development, all other nations will need to make far more heroic and self-denying cuts, the researchers conclude, to forestall dire consequences from average global warming exceeding 2°C (3.6°F) in coming decades.

If warming tops 2°C, the effects become potentially hazardous to human infrastructure, according to the United Nations Intergovernmental Panel on Climate Change: Agricultural yields could drop, diseases (especially those borne by mosquitoes) will spread more easily, people worldwide might face more drought and water shortages, and extreme weather will become more common.

Emissions Squeeze

Summarizing results of the new analysis, its lead author, Glen Peters, senior researcher at the Center for International Climate and Environmental Research–Oslo (CICERO) in Oslo, Norway, and his collaborators report that “combined, the EU, US, and Chinese pledges leave little room for other countries to emit CO2 if a 2 °C limit is the objective, essentially requiring all other countries to move towards per capita emissions 7 to 14 times lower than the EU, USA, or China by 2030.”

He and his colleagues published their analysis on 15 October in Environmental Research Letters.

“Developing countries are emitting far less per capita than developed countries do,” said atmospheric scientist Susan Solomon at the Massachusetts Institute of Technology in Cambridge, a coauthor on the new paper. In the United States, “we’re about something on the order of double the Europeans, but we’re around the order of 100 times, literally 100 times, Kenyans or Ethiopians,” she added.

Under current emissions pledges, carbon released collectively by just the United States, EU, and China through 2030 will account for 79% of the world’s allowable emissions that could keep warming below 2°C, the paper’s authors conclude. But if the biggest emitters sustain that same emission rate beyond 2030, warming closer to 3°C would result by the end of the century.


Next month, a high-profile, 12-day climate meeting known as the 21st Conference of the Parties (COP21) will convene in Paris. There, national emissions pledges called independent nationally determined contributions (INDCs) will influence negotiations toward a new international climate change agreement.

In anticipation of those negotiations, the researchers investigated the relative fairness of two potential ways of divvying up emission allowances among nations: an “inertia” approach that allots to each country the same fraction of allowable emissions in the future as they have now and an “equity” approach granting each country a share of allowable emissions based on its percentage of the world’s population. The inertia approach won’t aid developing countries, the researchers concluded, because the large emitters would keep their current shares of global emissions.

If the biggest emitters “don’t put themselves on a 2°C consistent pathway, then we quickly use up our available carbon budget,” said Louise Jeffrey, a scientific researcher at Potsdam Institute for Climate Impact Research who did not contribute to the new analysis.

Equity Versus Inertia

The equity approach, which the study authors deemed more fair, would allow developing countries to emit more than they currently do, easing further economic development in those nations. But the approach could require some countries to cut emissions at an infeasible rate, the researchers warned.

Nearly 2 years ago, the body convening the Paris meeting—the United Nations Framework Convention on Climate Change (UNFCCC)—asked each country to state its INDC well in advance of COP21, which begins 30 November. Even though researchers project that the globe will overheat and see emissions distributed unfairly, Nick Nuttall, a UNFCCC spokesperson, emphasized that INDCs represent a starting point for COP21 and that negotiations will progress beyond just these pledges.

Nuttall added that the countries and the UNFCCC know that the INDCs currently don’t add up to an emissions reduction that will keep the globe below a 2°C warming. Today, in a press conference, UNFCCC released its own report of aggregated effects from submitted INDCs, which will provide a foundation for the Paris meeting.

“Paris needs to send a signal to the entire world, including the power sector and the energy sector, that we are now embarking on a super low-carbon trajectory,” said Nuttall.

—Cody Sullivan, Writer Intern

Citation: Sullivan, C. (2015), Targets of biggest global carbon emitters flunk fairness test, Eos, 96, doi:10.1029/2015EO038423. Published on 30 October 2015.

© 2015. The authors. CC BY-NC 3.0
  • Roger Clifton

    The article dangerously associates the concept of a 2° limit to warming with an “allowable” rate of emission.

    We should not forget that our climate experts have told us that any increase of greenhouse gases inevitably leads to an increase in temperature. The Copenhagen Diagnosis of 2009 said that we might achieve this 2° limit if we reached near-zero emissions by 2100, after a (relentless) cutting of emissions in the interim.

    Now that we know that any emission of fossil carbon whatsoever does permanent damage to the greenhouse, any continuing rate of emission becomes a crime, not an “allowance”. We never had a right to emit in the first place and no one has a right to continue.

    If there is any compelling obligation on the part of developed to developing nations it should be to provide them with noncarbon power. It is ironic that the mass production of nuclear power plants was once seen as a disaster for the environment, but now may be the best means of saving it.

  • David Huard

    You’re right, but I see this as a way to frame the issue in such a way that no one country can wiggle out of the impacts it has on the rest of the world. While the 2C limit is non-binding from a legal standpoint, there are expectations that countries are ethically binded to it.

  • dankd

    This seems deliberately obtuse- the major emitters simply haven’t been willing yet to make pledges of reductions sufficient to keep us below 2 C with high confidence. That doesn’t mean everyone will have to emit even less, it means we can’t be confident we’ll stay below 2 C. The other emitters aren’t any more bound to make commitments that keep us below 2 C than the major emitters. No?