Decomposing the 2010 Global Carbon Dioxide Emissions Rebound

In January, Glen Peters et al. published a short paper in Nature Climate Change on trends in global carbon emissions in the wake of the global financial crisis. The key point was that the rebound in emissions in 2010 was much more rapid relative to the previous trend than in previous economic downturns as illustrated in this figure:



Emissions have returned to the trend that held during the last boom rather than there being a break in trend. Our article, appearing in the same journal, examines the reasons for this using the Kaya Identity. In 2010 GDP grew rapidly and both energy intensity of GDP and the carbon intensity of the energy input (grams of carbon per joule) increased:



In recent decades both the latter factors have declined, but since 2001 carbon intensity has risen due to the carbonization in India and China. Energy intensity does seem to rise in the recovery from recessions but in the past has been mitigated by declining carbon intensity.

The text of our media release follows:

TUESDAY 13 MARCH 2012

GLOBAL EMISSIONS SURGE BACK AFTER GFC

A recent spike in worldwide carbon emissions growth was caused by the rebound from the global financial crisis and is likely to be a one-off, according to a new study from The Australian National University.

The study found that global carbon emissions remain on a relentless upward trend, though efforts to shift to low-carbon energy and cut energy demand are bearing some fruit.

Led by Dr Frank Jotzo, director of the Centre for Climate Economics and Policy in the ANU Crawford School, the study traced the causes of a surge in carbon emissions during 2010. It found that the surge was due to a combination of unusual factors and was unlikely to happen again.

“The global economy grew very quickly in 2010. In addition, relatively low fossil fuel prices and fiscal stimulus spending on energy-intensive activities like construction contributed to a global emissions surge,” said Dr Jotzo. “The global mix of energy sources also shifted slightly towards higher-carbon sources during 2010.

“The 2010 emissions surge was exceptional. It is likely that global emissions growth slowed in 2011 and the fragile condition of the world economy suggests moderate emissions growth for 2012 as well.”

Dr Paul Burke, a co-author of the study and energy economist at ANU, added that 2010 saw a rare occurrence of energy demand outpacing world economic output, or GDP, as the world rebounded from the GFC.

“For energy demand to grow faster than GDP is most unusual,” said Dr Burke. “Over the last four decades this has only happened on four occasions. Apart from 1990, when the Soviet Union collapsed, the effect was never as strong as it was in 2010.”

The researchers also found that global carbon emissions growth is likely to slow in years to come.

“Thanks to policy efforts to improve energy efficiency and shift to lower-carbon energy supply, combined with greater availability of natural gas and falling costs of renewable energy technologies, we can expect slower emissions growth,” said Dr Jotzo.

“For example, Australia’s emissions from energy and industry fell slightly over the year to September 2011. This was mainly due to a reduction in Australia’s power use and less coal-fired electricity in the energy supply mix. The use of more hydropower, a ramp up of other renewable energy, and energy savings all contributed to the outcome.

“Cutting global emissions remains an enormous challenge, because of the strong underlying growth momentum, particularly in developing countries. Energy efficiency will need to be improved at a rate of knots, and zero-carbon sources deployed faster. China, in many respects, is leading the way, but much stronger policy action is needed in just about all countries,” he said.

The study has been published in the journal Nature Climate Change.

For interviews:

Dr Frank Jotzo – 02 6125 4367
Dr Paul Burke – 02 6125 6566

For media assistance: Sarina Talip – 02 6125 7988