An iceberg off Ammassalik island, Greenland. Photograph: John McConnico/AP

The reports from the Intergovernmental Panel on Climate Change (IPCC) are balanced and comprehensive documents summarizing the impact of global warming on the planet. But they are not without imperfections, and one of the most notable was the analysis of future sea level rise contained in the latest report, issued in 2007.

Given the complexities of forecasting how much the melting of the Greenland and West Antarctic ice sheets will contribute to increases in global sea level, the IPCC chose not to include these giant ice masses in their calculations, thus ignoring what is likely to be the most important source of sea level rise in the 21st century. Arguing that too little was understood about ice sheet collapse to construct a mathematical model upon which even a rough estimate could be based, the IPCC came up with sea level predictions using thermal expansion of the oceans and melting of mountain glaciers outside the poles. Its results were predictably conservative — a maximum of a two-foot rise this century — and were even a foot lower than an earlier IPCC report that factored in some melting of Greenland’s ice sheet.

Permafrost in Siberia. Methane emissions from the Arctic permafrost increased by 31% from 2003-07, figures show. Photograph: Francis Latreille/Corbis

Scientists have recorded a massive spike in the amount of a powerful greenhouse gas seeping from Arctic permafrost, in a discovery that highlights the risks of a dangerous climate tipping point.

Experts say methane emissions from the Arctic have risen by almost one-third in just five years, and that sharply rising temperatures are to blame.

I hate to say I told you so, but I have predicted the failure of the Copenhagen summit to agree to binding commitments for over a year.

The Copenhagen fiasco was not just foreseeable, it was inevitable. The inability of the international community to break the climate deadlock reflects the incompatible national interests and demands that divide the west and the rest. This is now a permanent feature in what is likely to become an indefinite moratorium on international climate law-making.