IPCC identifies measures to limit climate change

Media Release 4 May 2007

IPCC identifies portfolio of measures to limit climate change

We have the technology, and it need not cost the earth

The Intergovernmental Panel on Climate Change (IPCC) has just released the Summary for Policymakers of its Working Group 3 report Climate Change 2007: Mitigation of Climate Change. This summary was approved at a plenary in Bangkok, Thailand, this week.

Professor Ralph Sims of Massey University is a coordinating lead author of the chapter on energy supply and was one of the New Zealanders at the plenary. ‘As scientists, we’re delivering a strong but positive message. Action is required. The situation is urgent. But it’s not beyond repair. Many energy efficiency and energy supply technologies and practices to reduce greenhouse gas emissions are available now. And mitigation measures will bring many other benefits, some of which are in fact expected to save us money.’

The report confirms that greenhouse gas emissions are rising fast. Emissions of the key greenhouse gases covered by the Kyoto Protocol have increased by 70% between 1970 and 2004. Existing policies have not made a noticeable dent in the overall upward trend ‘Without additional measures, we expect global greenhouse gas emissions to reach 25-90% above 2000 levels by 2030,’ say Professor Sims.

The report says: ‘In order to stabilise the concentration of greenhouse gases in the atmosphere, emissions would need to peak and decline thereafter, The lower the stabilisation level, the more quickly this peak and decline would need to occur. Mitigation efforts over the next two to three decades will have a large impact on opportunities to achieve lower stabilization levels‘.

‘One significant finding,’ says Professor Sims, ‘is that studies from all regions of the world point to substantial health benefits from reducing greenhouse gas emissions, because of lower air pollution. So much so, that the health benefits could offset a substantial fraction of the costs of such reductions.’

Currently the atmospheric greenhouse gas concentration is about 430 parts per million (ppm), carbon dioxide equivalent (CO2-eq). [The current atmospheric concentration of carbon dioxide is 369 ppm; the rest is contributed by other greenhouse gases emitted from human activities.]
The report says that under a scenario in which emissions peak within the next decade and then reduce to half the current levels or less by 2050, eventual warming would be limited to about 2–2.4 °C above pre-industrial levels.

A stabilisation target of 530-585 ppm CO2-eq is projected to limit warming to 2.8-3.2 °C above pre-industrial, under a scenario where emissions peak in the period 2010-2030. This scenario is estimated to slow annual GDP growth rates in 2050 by less than 0.1%. World-wide carbon prices of around 20–80 US dollars a tonne by 2030 would be consistent with this target.

The report says that such targets are achievable ‘by deployment of a portfolio of technologies that are currently available and those that are expected to be commercialised in coming decades’.

A wide range of mitigation technologies are listed in the report. The report says ‘investments in and world-wide deployment of low-GHG [greenhouse gas] emission technologies as well as technology improvements through public and private research, development and demonstration would be required for achieving stabilisation targets as well as cost reduction.’ However, so-called ‘geo-engineering options’ which hit the headlines from time to time, such as inserting material into the upper atmosphere to block sunlight, are described as ‘largely speculative and unproven, and with the risk of unknown side-effects’.

ends

© Scoop Media