Tuesday, May 08, 2007

U.N. say Climate Change can be Halted.

Experts from the United Nations have concluded that it is still possible to avert global warming and climate change, but the world needs to act immediately to do so. In a recent report, the UN Intergovernmental Panel on Climate Change (IPCC) has stated that a range of established and emerging technologies including renewables and nuclear power, along with carbon capture and sequestration are needed to reduce greenhouse gas emissions, particularly CO2, to a level where global warming would be stabilised. The refusal of the US to tackle the issue, and also the massive volumes of carbon expected to be emitted by developing nations such as China and India, are predicted to increase global temperatures by up to 6 degrees C during the next century.

The report asserts that renewable sources of energy could be increased to provide 35% of the world's electricity by 2030, up from the 18% it currently generates, and that nuclear could provide 18% by that same date, meaning a relatively marginal increase from 16% as now. It is worth pointing out however, that many of the existing nuclear power pants will need to be decommissioned and replaced by new before then. Biofuels are also promoted as offering the potential to cause significant reductions in emissions from transportation. However, as I have stressed in previous postings, it appears unlikely that the massive quantities of petroleum that the world currently gets through to run the global fleet of vehicles, including aircraft and ships, could be matched in kind by biofuels, unless new technology based on algae is successfully introduced to make biodiesel on a huge scale, otherwise there is insufficient arable land available to grow fuel-crops without severely compromising food production.

Energy efficiency is sensibly promoted too, and also quite blue-skies methods, such as putting a shield in space to screen-out sunlight are mentioned but are considered to be at best "speculative". Carbon offsetting appears strangely absent in the proposal, where for example a firm might be paid to plant trees to soak-up the CO2 emitted by its fleet of planes. Trading carbon credits between nations appears likely. The whole venture is estimated to cost about 1% of the world's GPD, which is perhaps a price well worth paying.

The main recommendations of the report can be summarised:

Lifestyle, which means cutting back on personal emissions (i.e. travelling less, and ideally not by air).

Energy supply: as noted, with a bigger share from renewables and nuclear.

Farming and Forestry: careful farming to retain carbon in the soil and minimise emissions of CO2 and methane too?

Industry: cut back emissions from highly polluting manufacturing plants.

High-tech means: the giant sun-shield and fertilizing the oceans to grow more phytoplankton to absorb CO2 from the atmosphere are thought to be unproven.

Related Reading.
IPCC Fourth Assessment Report.
The Independent, "Climate Change can be Halted", by Michael McCarthy. http://news.independent.co.uk/environment/climate_change/article

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