Skip to main content

Climate Change

Volume 448: debated on Tuesday 4 July 2006

To ask the Secretary of State for Environment, Food and Rural Affairs what research his Department has (a) commissioned and (b) reviewed on the (i) chemical make-up and (ii) environmental impact of aircraft trails; and if he will make a statement. (79517)

To ask the Secretary of State for Environment, Food and Rural Affairs what research he has evaluated on the effects of condensation trails on climate change. (80666)

[holding answer 3 July 2006]: The Department for Environment, Food and Rural Affairs does not directly undertake work in this area, but closely monitors research commissioned by the European Union, Research Councils and other Government Departments to identify, characterise, and assess the impact of aircraft emissions on global climate change.

A major scientific report assessing the contribution of aircraft to climate change, “Aviation and the Global Atmosphere”, was published in 1999 by the Intergovernmental Panel on Climate Change (IPCC). More recently, research carried out under the EU 5th Framework Project, TRADEOFF, has improved modelling techniques and reduced estimates of contrail radiative forcing by two fold compared with the previous estimate from the IPCC. Research carried out under the TRADEOFF project also supported the conclusion that aviation potentially enhances cirrus cloud coverage.

Aircraft-induced cirrus clouds reduce the amount of solar radiation reaching the surface of the Earth, and so mitigate global warming. However, significant uncertainty surrounding this area of study makes it difficult to assess whether increased cloudiness would reduce or increase global warming trends.

To ask the Secretary of State for Environment, Food and Rural Affairs pursuant to the answer of 23 May 2006, Official Report, column 1692W, on greenhouse gases, what assessment he has made of the reasons for the rise in carbon dioxide emissions between 1997 and 2004. (81214)

The rise in carbon dioxide (CO2) emissions between 1997 and 2004 was caused by higher than anticipated levels of economic growth and the recent rise in global energy prices which has altered the relative prices of coal and gas. However, CO2 emissions were still about 5.6 per cent. below 1990 levels and we expect CO2 emissions to fall again in the future given longer term expectations on fuel prices and as a result of policies introduced under the new Climate Change Programme.

To ask the Secretary of State for Environment, Food and Rural Affairs what estimate he has made of the cost of achieving the target of increasing by 20 per cent. by 2010 the energy efficiency of residential accommodation in England pursuant to Section 217 of the Housing Act 2004; and if he will make a statement. (77962)

The net costs and benefits of existing and new policies were calculated for the Climate Change Programme review and presented in 2005 prices. Existing household energy efficiency measures have a net present value benefit of £65 billion and new household energy efficiency measures announced in the 2006 Climate Change Programme have a net present value benefit to consumers in the region of £13.5 billion, over the life of the policies. This is because the energy savings far outweigh the up front costs of the measures. This figure excludes improvements in air quality, which would make the benefits greater, if included.

The evaluation synthesis report can be found at http://www.defra.gov.uk/environment/climatechange/uk/ukccp/pdf/synthesisccpolicy-evaluations.pdf. We intend to publish the appraisal synthesis report in due course.