Global CO2 emissions: increase continued in 2007

Global CO₂ emissions

Increasing global CO₂ emissions: the trend continues

In 2007, global CO₂ emissions increased by 3.1%, compared to 3.5% in 2006. China’s emissions accounted for two thirds of this increase. India, the USA and Russia each contributed about 10% to the global increase. Since 1990, global CO₂ emissions from fossil fuel use and cement production increased by about 34%.

These figures include CO₂ not only from fossil fuel combustion, but also from other industrial activities, such as cement clinker production, other fuel use (e.g., feedstock in the production of chemicals) and flaring and venting of unutilised gas in oil and gas production. Globally, these activities comprise only about 8% of the total of CO₂ emissions, but there are notable exceptions, such as China (13%) and Brazil (11%). CO₂ emissions from deforestation, underground coal fires and peat fires are not included because they are very uncertain, not well monitored or not directly related to human activities.

Underlying causes of increasing trends

The increase in global CO₂ emissions was mainly due to the combustion of the fossil fuels coal, oil and natural gas. Fossil fuel still remains the most used energy source to meet the growing energy demand. For the third year in a row, global energy growth slowed, rising by 2.4% in 2007, down from 2.7% in 2006, which is still above the 10-year average. The pattern of recent years, which has seen a robust growth in demand in China and the rest of Pacific Asia, was continued with China’s primary energy consumption rising by about 8% in 2007, due to the continued economic growth.

Global fossil CO₂ emissions from fossil fuel in 2007: impact of weather conditions and high fuel prices

In 2007, global emissions of the main greenhouse gas carbon dioxide (CO₂) from fossil fuel combustion increased by about 3.2%, which is about the same as the 3.1% increase in 2006. These figures are based on a preliminary estimate by the Netherlands Environmental Assessment Agency (PBL) using BP energy data to estimate emissions in 2006 and 2007 (BP, 2008). The increase in 2007 is mainly due to a 4.5% increase in coal consumption:

• global CO₂ emissions from coal combustion increased by 4.5% (+500 megaton CO₂). China contributed most to this increase with an 8% increase in 2007 (vs 12% in 2006). In the rest of the world coal combustion emissions increased by 2.2%.
• global CO₂ emissions from combustion of natural gas increased by 3.1% (+200 megaton CO₂), mainly due to increasing consumption in China, Russia, Japan and Turkey.
• global CO₂ emissions from combustion of oil products increased by only 1.1% (+100 megaton CO₂), mainly due to a decrease in consumption in OECD countries of 0.9%, on average. In non-OECD countries, oil consumption increased in 2007 by 3.8%. China, India, Saudi Arabia and Brazil contributed most to this increase.

CO₂ emissions from fossil fuel combustion in China increased in 2007 by 7.6%. In the USA, according to the BP data, CO₂ emissions increased in 2007 by 1.8%, relative to 2006. CO₂ emissions from fuel combustion in the European Union countries “EU-15” decreased by 1.9% in 2007; in 2006 the emissions remained almost constant.

Weather conditions and high fuel prices affect global energy consumption

High oil prices of recent years have had their impact on oil consumption. OECD consumption fell by 0.9% in 2007. In Europe, a relatively warm winter, together with high fuel prices, have had a mitigating effect on CO₂ emissions, which decreased by about 2% last year. In 2006, CO₂ emissions from the EU-15 remained constant, which was confirmed in a recent report by the EEA, which compiled data from the 15 original Member States. In the USA, relatively cold winter and warm summer temperatures in 2007, combined with a decline in non-fossil-fuelled electricity generation, resulted in increases in CO₂ emissions from space heating and cooling. Overall, in the USA in 2007, CO₂ emissions increased by 1.8%, compared to 2006.

The top 5: China, USA, European Union, India, and Russia

Having surpassed the USA’s emissions in 2006 by 8%, China’s CO2 emissions are now estimated to be about 14% higher than those from the USA. With this, China tops the list of CO₂ emitting countries, having about a quarter share in global CO₂ emissions (24%), followed by the USA (21%), the EU-15 (12%), India (8%) and the Russian Federation (6%). Together, they comprise 71% of global CO₂ emissions. However, since population size and level of economic development differ considerably between countries, the emissions expressed per person show a largely different ranking: CO₂ emissions per person from the USA, Russia, EU-15, China and India are presently about 19.4, 11.8, 8.6, 5.1 and 1.8 metric ton CO₂, respectively.

Half of global cement production takes place in China

Of all industrial non-combustion processes, the cement clinker production process is the largest source of CO₂. It contributes around 5% to the total of global CO₂ emissions from fuel use and industrial activities. With a production increase of 10% in 2007, China now has a share in global cement production of about 50%.

Cement manufacturing is responsible for almost 20% of China’s CO₂ emissions, when including those from fuel combustion for heating the kilns. The rebuilding of houses for over 5 million people, after the earthquake which recently hit the Sichuan province, may cause the cement demand to soar even further. Other economic activities causing China’s CO2 emissions to increase further are electricity generation and steel production. Although China’s road transport emissions are also increasing fast, in absolute figures the CO₂ emissions from power generation are about ten times larger.

The example of China illustrates that, when other countries will start to show similar fast urbanisation and industrialisation, CO₂ emissions from the building industry will also be boosted due to large increases of CO₂ emissions from cement manufacturing. In the last five years, the largest increases in cement related emissions in other countries − in absolute amounts − are seen in India, Turkey, Vietnam, Mexico, Spain, Pakistan and Saudi Arabia. However, these do not compare with China’s increase, which was ten times larger than runner-up India

Methodology and data sources

The recent trend estimates were compiled by PBL, using the trends in most recent data on fossil fuel consumption from the BP Review of Energy 2007 (BP, 2008) and cement production data through 2007, published by the US Geological Survey (USGS). The CO₂ estimates for 2006 and 2007 were compiled by PBL, using the detailed national CO₂ emission estimates for energy use through 2005, compiled by the International Energy Agency (IEA, 2007), estimates for flaring and venting through 2004, compiled by CDIAC, supplemented with data from the US Energy Information Administration (EIA), national submissions to the UN Climate Secretariat (UNFCCC) and data from the Global Gas Flaring Reduction partnership (GGFR) for 2004/2005 and own estimates for CO₂ emissions from cement clinker production.

The estimates of CO₂ emissions do not include CO₂ emissions from deforestation/logging and are calculated using default CO₂ emission factors, recommended by the Intergovernmental Panel on Climate Change (IPCC). CO₂ emissions from underground coal fires in China and elsewhere and the peat fires and peat emissions from dehydration in Indonesia are not included, either. The magnitude of these sources is very uncertain; according to recent research, annual CO₂ emissions from coal fires are estimated at 150-450 megaton CO₂ in China (ITC, 2007) and 400-5000 megaton CO₂ from peat in Indonesia (Hooijer et al., 2006). Though significant, being highly uncertain, CO₂ emissions from the decay of organic materials of plants and trees, which remain after forest burning and logging, are also not included.

Data quality and uncertainties

The energy data annually published by BP, appears to be reasonably accurate: based on older BP energy data, the increase in 2005 in global CO₂ emissions from fuel combustion was estimated at 3.3%, globally. With presently available and more detailed statistics of the International Energy Agency (IEA) for 2005, the increase is now estimated at 3.2%. At country level, differences can be larger, in particular for countries with a large share in international marine fuel consumption (so-called bunkers) and with a large share in non-combustion fuel use. Moreover, energy statistics for fast changing economies, such as China, are less accurate than those for the traditional, industrialised countries within the OECD.

Other recent analyses of CO₂ emissions from fossil-fuel use and cement production have suggested that the uncertainty of CO₂ emission estimates could be about 2 to 3% for the USA and as high as 15 to 20% for China (Gregg et al., 2008). However, the estimate for China is based on revisions of energy data for the transition period in the late 1990s, which may not be applicable to more recent energy statistics. Based on subsequent revisions of emission estimates made by the IEA, PBL estimates the uncertainty in the preliminary estimates for China − caused by uncertainty in the energy data − at about 10%

For additional background information, see:

• Global CO2 emissions per sector 1970-2004 (in Dutch with table in English)
• Global greenhouse gas emissions increased 75% since 1970

References

• BP, 2008: Statistical Review of World Energy 2007
• Gregg, J.S., Andres, R.J. and G. Marland, 2008): China: Emissions pattern of the world leader in CO2 emissions from fossil fuel consumption and cement production. Geophys. Res. Lett., 35, L08806, doi:10.1029/2007GL032887.
• Hooijer, A., Silvius, M., Wösten, H. and S. Page, 2007: PEAT-CO2. Assessment of CO2 emissions from drained peatlands in SE Asia. Delft Hydraulics report Q3944.
• IEA, 2007: CO2 Emissions from Fuel Combustion 1971-2005
• ITC, 2007: CO2 emissions from underground coal fires in China