When not in denial, the US government's approach to climate change has been dominated by faith in the "technological fix" rather than changes in behaviour (US answer to global warming: smoke and giant space mirrors, January 27). There are a number of reasons to be wary of this strategy. First, the science might not work. As you point out, the technologies in which hope is invested are either enormously expensive or too far from commercial use to be of much help. Second, climate change is caused by the unintended consequences of the use of technology. Who knows what environmental problems orbital mirrors and nuclear fusion might bring in their train? Third, and most crucial, technology perpetuates the illusion that business as usual is a viable proposition. But without accompanying changes in behaviour, technological advances are swallowed up by increased demand and unwise decisions: witness the use of hybrid technology in 4x4s, which makes them worse emitters of climate-change gases than the normal family saloon. In sum, good environmental science must be accompanied by good environmental citizenship on the part of both individuals and organisations, and there is little sign that either the US or the UK government understands this yet.
Professor Andrew Dobson
School of politics, international relations and the environment, Keele University
It is encouraging to learn from David Adam's article that the US government has moved from denying global warming to recommending that attention be given to schemes for reducing the amount of sunlight reaching the Earth's surface, thus producing a cooling. Along with colleagues, I am examining one such scheme. Cooling could be achieved, in principle, by increasing the reflectivity of low-level shallow maritime clouds by atomising sea water to produce tiny droplets which enter the clouds. A number of important possible meteorological and safety ramifications must be fully examined before deployment of any such scheme would be justified. Although the ideal solution would be for fossil-fuel burning to be reduced to halt global warming, such a reduction is highly unlikely to occur in the near future.
National Centre for Atmospheric Research, Boulder, Colorado, USA
The suggestion that seeding the oceans with iron is an "extreme idea" and would produce pollution is incorrect. Iron is a micronutrient necessary for the formation of chlorophyll in plant plankton, and without it oceans become deserts largely devoid of life. Ships and aircraft crossing iron-deficient areas could gently fertilise these by the inclusion of an iron compound in their engine fuels. The iron particulates shed in an engine's exhaust would spread widely over ocean areas and also combine with the dimethyl sulphide from plankton to produce iron based sulphate aerosols, which seed the formation of clouds to reflect sunlight. Fertilisation of the oceans could lead to carbon sequestration on as great a scale as any land-based proposal.
Your report (Welcome in the valleys as mines reopen, January 30) highlights a long-overdue resurgence in those prepared to invest in and support indigenous coal mining. With new clean coal technologies, the fuel can and should be better utilised as Britain faces a future perilously overdependent on imported gas. Britain has vast untapped coal reserves and there are potential new prospects if investment and government policy backing can be secured, as can be seen with new mining projects in Wales and Yorkshire. Encouragingly, the government is looking closely at new clean coal power stations as part of Britain's future energy mix. Hatfield colliery in Yorkshire is set to reopen next year, in light of the strong market for coal, with plans to build one of Britain's first clean coal power stations alongside it. These power stations gasify coal and capture 90% of sulphur emissions, and are backed by Friends of the Earth. Higher global coal prices mean mining coal at home is now more lucrative, and the steeper rise in the price of gas means coal is a cheap option for power companies.
Co-author, Electrifying Britain - Forward with Coal, Gas or Nuclear?