Saturday, 29 August 2009

Control Coal to Mitigate Climate Change?

Top CO2 emitting countries have a large proportion of world coal reserves

Coal consumption is the key practical issue to be addressed in tackling the problems of climate change. Unsurprisingly trends in CO2 emissions bear a strong relation to coal consumption. Compare 'Coal Consumption of Top 15 CO2 emitters' (Figure 8.1) in this post with that showing the CO2 emission trends in the previous post.

Figure 8.1 Coal Consumption of Top 15 CO2 Emitters (click image to enlarge)

Coal is the major source of anthropogenic CO2 and a significant source of other environmental pollutants, but coal is the most abundant fossil fuel that provides an intense energy source and is relatively cheap.

Many economies have significant dependence on coal in their primary energy mix and its use provides electrical power and supports industry. To transform coal dependent economies, even if the will to do so existed, would take great efforts.

The coal reserves of the Top 5 CO2 emitters are shown in Figure 8.2. Apart from Japan these countries have large coal reserves, amounting to nearly 70% of the world total.

Figure 8.2 Coal Reserves of Top 5 CO2 Emitting Countries

An apparently reasonable strategy for combating climate change would be to phase out the use of coal worldwide or to reduce its use drastically. Technically and scientifically this would be a practical solution for CO2 mitigation but politically it would pose extreme challenges. (Issues to be considered in a future post)

Considering their substantial coal reserves, could the high CO2 emitting countries be persuaded of the wisdom of leaving their coal in the ground?

Claims about 'clean coal' technologies disguise the fact that the only clean coal technology is a coal technology in which all CO2 is captured and sequestered. As yet, although elements of the technology have been used in other sectors, the crucial Carbon Capture and Storage (CCS) technologies are still being developed and pilot tested.

A flexible CCS technology that could retrofitted to a wide range of existing power plants would be the ideal, but that seems an unlikely prospect in the short to medium term.

Can we control coal use to mitigate climate change? Have we the wisdom to leave it in the ground or only to use it when the CCS technology has been developed?

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