New estimates show China's carbon emissions were less than previously thought

August 19, 2015, University of East Anglia
Credit: Alfred Palmer/Wikipedia

China's carbon emissions have been substantially over estimated by international agencies for more than 10 years, according to research co-led by the University of East Anglia.

From 2000-2013 China produced 2.9 gigatonnes less than previous estimates of its cumulative emissions. The findings suggest that overestimates of China's emissions during this period may be larger than China's estimated total forest sink - a natural carbon store - in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

Published tomorrow in the journal Nature, the revised estimates of China's were produced by an international team of researchers, led by Harvard University, UEA, the Chinese Academy of Sciences and Tsinghua University, in collaboration with 15 other international research institutions.

The team re-evaluated emissions from the burning of fossil fuels and from 1950-2013. They used independently assessed activity data on the amounts of fuels burned and new measurements of emissions factors - the amount of carbon oxidised per unit of fuel consumed - for Chinese .

Nearly three-quarters of the growth in from the burning of fossil fuels and cement production between 2010-2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty due to conflicting assessments of energy consumption and emission factors. Indeed, using different official sources of activity data and emissions factors can result in estimates that vary by up to 40 per cent in a given year.

Lead UK researcher Prof Dabo Guan, of UEA's School of International Development, said the key contributor to the new estimates was fuel quality, which for the first time was taken into consideration in establishing emission inventories - something the Intergovernmental Panel on Climate Change (IPCC) and most international data sources had not.

"China is the largest coal consumer in the world, but it burns much lower quality coal, such as brown coal, which has a lower heat value and carbon content compared to the coal burned in the US and Europe," said Prof Guan.

"China is one of the first countries to conduct a comprehensive survey for its coal qualities and a global effort is required to help other major coal users, such as India and Indonesia, understand their physical coal consumptions as well as the quality of their coal types.

"Our results suggest that Chinese CO2 emissions have been substantially over estimated in recent years. Evaluating progress towards countries' commitments to reduce CO2 emissions depends upon improving the accuracy of annual emissions estimates and reducing related uncertainties. These findings represent progress towards improving estimates of annual global carbon emissions."

The researchers found that total energy consumption in China was 10 per cent higher between 2000-2012 than the value reported by the country's national statistics. However, emission factors for Chinese coal were on average 40 per cent lower than the default levels recommended by the IPCC. Emissions from China's cement production were 45 per cent less that recent estimates.

The revised estimate of China's CO2 from fossil fuel combustion and cement production in 2013 is 2.49 gigatonnes of carbon. This is up to 14 per cent lower than the emissions reported by previous assessments, including those by the Carbon Dioxide Information Analysis Centre (CDIAC) in the US and the Emissions Database for Global Atmospheric Research (EDGAR) in the EU, which are the official data sources for the IPCC Fifth Assessment Report (AR5) - providing scientific evidence for climate change policy negotiations in Paris later this year.

The figure is also about 10 per cent less than the estimate given for China in the most recent publication of the Global Carbon Project, which updates annually the emissions and their implications for future trends.

Prof Corinne Le Quéré, director of the Tyndall Centre for Climate Change Research at UEA, co-leads the publication of annual updates of emissions for the Global Carbon Project. She said there were a lot of uncertainties in Chinese data, especially given discrepancies between national and provincial figures.

"There is still a lot of work to do," said Prof Le Quéré. "The strong message here is that as we refine our estimates of carbon we get closer to an accurate picture of what is going on and we can improve our climate projections and better inform policy on ."

Explore further: Global carbon emissions set to reach record 36 billion tonnes in 2013

More information: 'Reduced carbon emission estimates from fossil fuel combustion and cement production in China' is published in Nature on August 20, 2015. DOI: 10.1038/nature14677

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2 / 5 (8) Aug 19, 2015
DOI doesn't recognize the link to the paper.

So does this mean that the climate models that predicted Armageddon were wrong in the amount of CO2 that was calculated?

What about all the articles screaming about how much carbon went into the air? Certainly, these two need to be revised.

That would at least partly explain why the models failed.

On a darker note, could this be a way of cutting China lose from the "carbon reduction effort", probably because they have no intention of doing it anyway? "Don't worry guys, they're not putting out so much carbon that they need to do anything; only the Western societies do".

Nevertheless, once again it is demonstrated that policies allegedly intended to reduce carbon, but in practice wreck successful economies and scientific moralities are not justified. Again.
1 / 5 (3) Aug 19, 2015
And Chairman Mao was really Mother Theresa.
1 / 5 (4) Aug 19, 2015
New estimates show China's carbon emissions were less than previously thought

This has been a paid advertisement brought to you by, China, The People's Republic Of.
2 / 5 (8) Aug 19, 2015
Whatever the numbers, the extreme pollution in China is real and a big health issue. That is by far the more important issue, rather than counting how much CO2 was produced. We should focus on real issues.

It is a real issue. Californians are, by law, staring at a 50% reduction in gas usage because of these climate model predictions. Google California SB 350.

If the climate models are false (as is already known by observation), then every indicator that the models are even worse than we thought needs to be screamed from every mountain-top until the economic damage done is fixed, and the plans to wreak more damage stopped.

The entire world is under threat form greater and greater restrictions based on false models, and there is more and more evidence to prove it? Stop the presses. Now.

2.3 / 5 (6) Aug 19, 2015
Wait till they reveal how NASA and NOAA overcooked the temperature record.
2 / 5 (8) Aug 19, 2015
Wait till they reveal how NASA and NOAA overcooked the temperature record.

Conflict of Interest.

If there is no AGW, then the IPCC has no reason to exist, and the UN loses a lot of its Social Justice leverage.

1.9 / 5 (9) Aug 19, 2015
verkle is right, and it is a problem. Much of that nasty stuff, including the heavy metals, comes our way.

We really do ride Spaceship Earth. Ain't no window to open.
4.4 / 5 (7) Aug 19, 2015
Gee @denglish, if only this article was about climate models. Then maybe every single thing you just said might be vaguely relevant.

But then again... what are the odds?
Da Schneib
3.7 / 5 (3) Aug 19, 2015
Hope this doesn't encourage them to switch back to building coal-fired electrical plants. The really big increases coming in the future were due to that.

I'd like to know how the almanac figures for mined and burned coal are affected by this. Also it apparently doesn't help the smog in Bejing much, just sayin'.
5 / 5 (5) Aug 20, 2015
It will give them some breathing room for negotiations later this year. But China is pretty dedicated to reducing emissions. They may use this as a way to commit to less emissions cuts but I suspect they'll instead make deeper commitments based on these numbers.

And no - the current smog exists regardless of reducing the uncertainties around the exact emissions figures. Unfortunately.
Da Schneib
3.4 / 5 (5) Aug 20, 2015
Hopefully they've fully figured out that they'll get hosed more by global warming than any other large country. It seems so now but they're volatile. Ten years ago they were AGW deniers and their politicians were pretending that global warming was a plot to restrict their industrialization. I remain suspicious.
4.8 / 5 (5) Aug 20, 2015
Hopefully they've fully figured out that they'll get hosed more by global warming than any other large country. It seems so now but they're volatile. Ten years ago they were AGW deniers and their politicians were pretending that global warming was a plot to restrict their industrialization.

And yet they moved to corner the electric car market in that time. You never quite know with these kind of countries whether their public rhetoric represents their real position. China committed to a low-carbon economic transformation well over five years ago.
Da Schneib
5 / 5 (4) Aug 20, 2015
You never quite know with these kind of countries whether their public rhetoric represents their real position. China committed to a low-carbon economic transformation well over five years ago.
I was heartened to hear that they'd chosen to change their long-term electrical generation plans from coal to nuclear; the problems with nuclear are generally local rather than global. I'd say overall that's the most important factor here in terms of global warming. I'd hate to see that disturbed. There are significant pro-coal political forces in managed socialist economies.
3 / 5 (2) Aug 20, 2015
if only this article was about climate models.

CMIP5 models use C02 as a main climate change forcer. This includes man made C02, which must be estimated re: future output in order to look into the future.

This will help you learn more about the CMIP5 model:

According to this paper, China's carbon output was overestimated by 15%. If the model overestimated the output by 15%, then it has overly-high results, and that result is exponentially magnified as the model moves into the future.

Not ironically, this is pretty close to what we're seeing re: predictions and observations.

Another idea is that climate modelling is impossible due to the unknowns and variability, and the US cut carbon by 18% through crippling the economy, and China cut carbon by 15% by having a study published.
1 / 5 (3) Aug 23, 2015
Re: denglish, cherry picks with nil idea of Robust Statistics

Acts like ubavontuba, similarities abound. Key issue they both fail, other than statistics/means/medians etc are failures to understand key settled physics

further detailed re greenhouse gases here

Is well proven, never refuted. So question arises Where is the heat going, answer is obvious to anyone who has done high-school physics - the material with the higher specific heat/mass. That is, Oceans !

denglish's reporting is an outright lie, his naive attempt to pursue propaganda here, Eg my last post

denglish FAILs to address the warning by RSS

ie Last sentence of 1st para

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