On Greenhouse: There is a way, but where is the will?

The Third Assessment of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) was issued at the end of February but largely ignored by an Australia obsessed with petrol prices, electoral backlash and economic downturn. The Bush administration has just repudiated its campaign promise of modest cuts in carbon dioxide emissions by electricity companies on the grounds that it would exacerbate the Californian power crisis. Given these responses from the nations who are the largest per capita carbon dioxide emitters, what hope is there of an effective global response to the problem of climate change?

Research commissioned by the IPCC since the 1992 Rio climate summit has raised the estimated upper limit of average global temperature rise over the next century to 6 degrees Celsius. The warming will affect different regions differently by changing rainfall patterns and the frequency of severe storms. The third report was concerned with technological initiatives to mitigate temperature rise and showed that there is reason for optimism, provided governments give a lead to encourage changes in energy use.

Earlier remedial proposals in response to the Rio summit concentrated on the removal of carbon dioxide from power station exhaust or the cultivation of biomass to absorb mounting carbon dioxide emissions. While it is feasible to remove carbon dioxide from power station emissions this would cost about one fifth of the power output, raising prices correspondingly.

The carbon dioxide removed has to be stored somewhere. Storage on land is possible in natural gas fields and in aquifers but there are long-term maintenance and safety problems. Alternatively, the gas could be sequestered on the ocean bed as a liquid or a solid gas hydrate but there are doubts about the pipeline technology at such great depths and about the long-term stability of the deposits: the world’s deep ocean currents could bring the gas back to the surface over a period of centuries and catastrophic release of ocean bed gas has occurred in the geological past.

The planting of trees is the most popular biomass proposal. It appeals because governments can shift the onus for action onto individuals – car licence renewal notices this year include a pamphlet soliciting tax deductible contributions to the Greenfleet initiative, which claims that 17 trees will absorb during their lifetime the carbon dioxide emitted by the average car during one year.

One controversial biomass proposal is to encourage phytoplankton growth in the southern oceans by fertilisation with iron sulfate. A recent experiment in the southern ocean showed that increased plankton growth and carbon dioxide uptake occurred after ocean fertilisation, but the sheer size of the areas required for biomass, whether on land or at sea, is daunting: to absorb the carbon dioxide emissions of a 800 megawatt power plant requires a forest of 130 square kilometres!

But the science of "carbon sinks" – the areas of the world where carbon dioxide is absorbed – is still very inconclusive about where the main sinks are and how they operate and conservationists claim that currently in Australia, for every tree planted, ten are being cut down in the great Queensland land clearing catastrophe.

Despite the drawbacks, initiatives in carbon trading have already begun in which Japanese electricity utilities are gaining carbon credits by paying for tree plantations in New South Wales.

Responses to the prospect of global warming tend to the extremes of denialism (a small minority of the scientific community, backed by the energy industry, rejects the greenhouse thesis espoused by the majority through the IPCC) or of rapid environmental catastrophe triggered by sudden shifts in the circulation of the oceans. To find a balance between these views, it seems reasonable to encourage energy efficiency while promoting the introduction of new, carbon–free energy sources.

The third IPCC assessment approved wind and solar electricity generation, and hydrogen powered fuel cells for cars to meet the demands of a "decarbonised" energy supply in the 21st century. These technologies have developed substantially since the Rio summit and will soon be competing with conventional energy sources in remote windy or sunny regions. California, despite its current power problems, has a progressive policy towards the introduction of electric and hybrid vehicles.

To encourage energy efficiency, market economists advocate the use of a carbon tax to raise energy prices to properly reflect long-term environmental costs due to global warming. But the recent response to high petrol prices due to the fuel excise in Australia shows how politically difficult this will be. Our federal government instead has reluctantly introduced the Renewable Energy Act, which earmarks $ 400 Million for greenhouse abatement projects. This act is unfortunately tarnished by approving the use of woodchip fired power generation, which conservationists believe will encourage the logging of old-growth forests.

The prospects are that the new technologies highlighted by the IPCC will have to be adopted eventually – but do not hold your breath for strong government action in Australia or the United States in the current economic and political environment.