How big is the energy challenge of climate change? The technological advances needed to stabilize carbon dioxide emissions may be greater than we think, argue Roger Pielke Jr, Tom Wigley and Christopher Green.

The irreconcilable differences between David S. Reay's Book Review of The Hot Topic (Nature 452, 31; 2008) and mine, expressed in Nature Reports Climate Change (see http://www.nature.com/climate/2008/0804/full/climate.2008.23.html), go to the heart of why there is now a crisis in climate policy. Reay seems to believe that agreement with a normative agenda precludes the need for rigorous evaluation of evidence or of proposed policy actions, and so falls into the same traps as Gabrielle Walker and David King, the authors whom he praises. (Correspondence)

Low- and zero-energy buildings could have a huge impact on energy use and carbon emissions. We have the technologies, but if they are to mitigate climate change, green-building design must hit the mass market : a report.

The budding carbon-offsets market could already be on its last legs, industry representatives say, if the latest European proposals are agreed. European negotiators went into a United Nations climate meeting in Bangkok this week warning developing countries that they need to step up to the challenge of climate change if they are to see additional money flowing into clean-development projects.

The Intergovernmental Panel on Climate Change (IPCC) has grossly underestimated the challenges of reducing and stabilizing greenhousegas emissions, according to an influential group of climate-policy experts.

How much energy, and of what sort, should we expect the world to be generating in the decades to come? This is a question of crucial importance to economics, development and the management of climate change. (Editorial)