Dear Ms Chapman, Mr Snowdome and Mr Sheridan

I am replying to your emails of 20, 22 and 23 June, following on from the 2 May reply my colleague Lucy Mundy sent to James Snowdome.

To your question on why my colleague “failed to mention any of this information, including the fact that one of the leading members of the IPPC recently admitted that Global Cooling is actually taking place”, I respond by noting that Mr Snowdome's original question did not ask for this information. Mr Snowdome asked:

“What steps are being taken to ensure that Britain will not be adversely effected [sic] when the Global Warming scam comes crumbling down as the world switches to a natural global cooling stage?”

Ms Mundy replied by noting that the science does not indicate we are heading towards global cooling. The Government does not accept that global warming is a scam. The science upon which the Government bases its policy on climate change mitigation and adaptation is sound. The assessments of the IPCC represent the consensus of thousands of scientists worldwide, based on peer-reviewed research. Objectivity is ensured by the broad and open review process (in which critics also participate) and shared responsibility for the report. No one government, organisation or individual has sole responsibility for any part of the report. The IPCC have made all the review comments, together with responses, publicly available for inspection on their web site at http://ipcc-wg1.ucar.edu/wg1/Comments/wg1-commentAgree.html .

The IPCC is not a politically motivated organisation as incorrectly claimed by Mr Snowdome, but a scientific one. Its task is to assess on a comprehensive, objective, open and transparent basis the scientific information relevant to understanding the scientific basis of risk of human induced climate change. This it does through well defined and transparent procedures (the “Principles Governing IPCC Work”) which are clearly documented on the IPCC website at www.ipcc.ch.

A critical examination of alternative explanations of the modern warming trend is part of the IPCC assessment process and these are mentioned in the Fourth Assessment Report. If there was clear evidence of future significant global cooling this would have been assessed in the report. It is true that the rate of warming has recently slowed as a result of natural climate variability, a fact that has been misinterpreted by sceptics as evidence that “global warming has stopped”. The fact is the long term trend is one of warming, and claims of global cooling cannot be made on the basis of short term climate variability.

The official position of the Solar Cycle Prediction Panel on solar cycle 24 is that there is at present no consensus among space scientists over whether this cycle will be more active or less active than cycle 23. Visit their web site at

http://www.swpc.noaa.gov/SolarCycle/SC24/index.html. Predictions that the world is headed towards a repeat of the Maunder Minimum are at best speculative. Even if there was to be a period of global cooling due to a downturn in solar activity during this century, in the long term climate forcing from rising levels of greenhouse gases will overwhelm any cooling trend.

I am unaware of any alleged comments claiming the world is headed towards global cooling by an alleged leading IPCC member. I would suggest the comments have been taken out of context or the “leading IPCC member” is in fact a reviewer critical of the IPCC's interpretation of the evidence.

We therefore have no current plans in place to prepare for global cooling. If the scientific evidence indicated global cooling was a risk, we would of course take this into account in forming policy. Having said this, we take the need to protect Britain, and indeed the world, from the impacts of climate change very seriously. Work is already underway in many areas of Government to ensure that its operations, investments and policies take into account the unavoidable impacts of climate change, and to facilitate adaptation in every sector of society. However, particularly with the development of the adaptation section of the Bill, the time is right for a national overview of what is already happening, and why, and what the risks of not taking action are for the economy, environment and society. Building on this baseline of the current situation, the Adaptation Policy Framework will consider the role that Government has to play in helping us all to adapt, and what the Government's plans are for moving forward. In this way, the APF will complement the framework and requirements set out in the Climate Change Bill, helping to ensure that going forward Government takes a joined-up and sustainable approach to adaptation, and is that the role of Government in helping us all to adapt is clear.

[Author ID2: at Fri Jul 11 13:06:00 2008 ]

I will now respond to some of your specific points from a scientific angle.

Global cooling

We know that a collapse of an important ocean current system, the North Atlantic Thermohaline Circulation, has led to rapid cooling around Europe in the distant past, and there are concerns from some scientists that future warming could trigger another collapse. However, most scientists consider this unlikely for the near future. The IPCC concluded that global warming may weaken the circulation, but not collapse it within this century. A weakening might offset some warming, but is unlikely to cause a cooling.

Climate Change and Supporting Evidence Thereof

Evidence shows that the Earth has warmed by 0.74°C over the last hundred years. Around 0.4°C of this warming has occurred since the 1970s. The Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) leaves us in no doubt that human activity is the primary driver of the observed changes in climate.

The main human influence on global climate is emissions of the key greenhouse gases - carbon dioxide (CO₂),methane and nitrous oxide. The accumulation of these gases in the atmosphere strengthens the greenhouse effect. At present, just over 7 billion tonnes of CO₂ is emitted globally each year through fossil fuel use, and an additional 1.6 billion tonnes are emitted by land use change, largely by deforestation. The concentrations of these gases in the atmosphere have now reached levels unprecedented for tens of thousands of years.

According to AR4, mean global temperatures are likely to rise between 1.1 and 6.4°C (with a best estimate of 1.8 to 4°C) above 1990 levels by the end of this century, depending on our emissions. This will result in a further rise in global sea levels of between 20 and 60cm by the end of this century, continued melting of ice caps, glaciers and sea ice, changes in rainfall patterns and intensification of tropical cyclones.

Furthermore, the Stern Review on the Economics of Climate Change concluded that climate change is the greatest long term threat faced by humanity. All countries will be affected but the poorest nations will be hit hardest. The costs of failing to tackle climate change far outweigh the cost of mitigation. At a minimum, a failure to tackle climate change will cost 5% of global GDP. Costs could run up to 20 per cent of GDP. The window of opportunity to reverse the rise in global emissions is narrowing and time is running out if we are to avoid catastrophic and dangerous climate change.

Climate change is, however, not an insoluble challenge. The technologies to reduce energy demand, increase efficiency and develop low-carbon electricity, heat and transport are within grasp. The costs are manageable at around 1 % of global GDP. The Government believes therefore that we must act early, across all countries and all sectors, if we are to keep costs down.

That is why the Government introduced the Climate Change Bill into Parliament in November last year. The Bill puts into statute legally binding emissions reduction targets and a long-term framework for achieving them. This legislation demonstrates the Government's commitment to taking action at home - to begin the transition to a low-carbon economy and strengthen the UK's ability to be global leaders in developing a future international framework for climate change.

Water vapour

Human activities do not directly affect the concentration of water vapour in the lower atmosphere. Although water vapour is a component of fossil fuel emissions, it is very quickly removed from the atmosphere by normal meteorological processes. By contrast, other greenhouse gases remain in the atmosphere for a long time before being removed by natural processes. Human activities are likely to have important indirect effects on the concentration of water vapour - as a warmer atmosphere holds more water vapour, this will form an important positive feedback on warming.

Reflection of sun's rays (Ms Chapman's request-791)

This argument is based on a misconception. The sun radiates energy from a surface of nearly 6,000˚C, which means this energy is mainly shortwave radiant energy which is largely unaffected by the atmosphere. The fraction of solar energy that is reflected by the surface and clouds goes straight up to space unaffected by greenhouse gases because it has exactly the same shortwave properties as the incoming solar energy. The fraction of solar energy that is not reflected is absorbed by the earth's surface which then radiates this energy into the atmosphere. Because the earth at about 15˚C is much cooler than the sun, this energy is radiated at much longer wavelengths (invisible infra red energy) than incoming solar energy. Because of their atomic structure, gases such as water vapour and carbon dioxide can trap some of this infra red energy radiating from the earth's surface thus causing the greenhouse effect. This is a perfectly natural process and the amount of infra red energy the earth radiates to space equals the incoming solar energy. But if the atmosphere is loaded with more greenhouse gases, as is happening at present, more infra red energy gets trapped so less energy gets radiated to space than is coming in. Therefore to restore the balance the earth must warm up.

Carbon dioxide

Carbon dioxide does not block out sunlight like clouds do. Clouds are basically water/ice droplets formed by the condensation of water vapour as it rises and cools in the atmosphere. It is these droplets that reflect sunlight. Non condensed water vapour also exists in the atmosphere, and from the previous paragraph you will know that it is largely transparent to sunlight, as is carbon dioxide.

It is true that higher atmospheric concentrations of carbon dioxide can speed up plant photosynthesis, a fact that is exploited in commercial greenhouses. But there are two caveats to beware of. Firstly, the rate of speeding up slows down before eventually levelling off as carbon dioxide concentration rises. Secondly, increasing concentrations of carbon dioxide in the atmosphere will cause climate change which is likely to increase the environmental stresses on the plants (e.g. through heat stress and droughts) thus negating any benefits.

Food production

Despite this, [Author ID2: at Fri Jul 11 13:06:00 2008 ]c[Author ID2: at Fri Jul 11 13:06:00 2008 ]C[Author ID2: at Fri Jul 11 13:06:00 2008 ]oncerns[Author ID2: at Fri Jul 11 13:09:00 2008 ]concerns[Author ID2: at Fri Jul 11 13:09:00 2008 ] over the availability of food - particularly recently, through rising food prices - are taken seriously. In December 2006 we published a wide-ranging study of food security which concluded that the UK, being a rich, open economy, has a very robust and diverse food supply. Food security is a legitimate concern but often food security is confused with national self-sufficiency or competitiveness. These two issues need to be considered separately.

Self-sufficiency is best seen as a broad indicator of the competitiveness of UK agriculture in meeting market demands at home and abroad. Defra uses Gross Value Added per person from agriculture as a more direct measurement of the economic sustainability of the agricultural sector in UK. Our vision for farming is for British consumption of British food to come from the skills, innovation, investment, branding, and quality assurance of the farming industry rather than from a policy that aims simply to maximise the level of self-sufficiency.

Food security is about ensuring consumers have access to a stable and adequate supply of food; it is not about maximising domestic production. The UK has long been a net importer of food and the Government believes that an important element in facilitating national and international food security is improved trading relationships based on more open international markets and a flexible, skilled and market orientated domestic agriculture sector that contributes to the diversity and resilience of food supply.

Given that Mr Sheridan's email contains personal insults against a member of my staff, I elect not to respond to his points.

Yours sincerely

Ali Davies

The Stern Review on the Economics of Climate Change can be found at:

http://www.hm-treasury.gov.uk/independent_reviews/stern_review_economics_climate_change/sternreview_index.cfm