The newspapers got excited when nations meeting in Montreal this month agreed plans to negotiate a successor to the Kyoto Protocol. But Europe's nascent market in carbon dioxide emissions took the talks in its stride, barely fluttering in response to the last-minute deal.

After a year of trading on the Leipzig-based European Energy Exchange (EEX), one of five such markets operating in Europe, the price of an allowance to emit one extra tonne of carbon dioxide during 2005–07 seems to be stabilizing at value of about €20 (US$24). A binding international agreement to cut emissions after 2012 would provide extra security for banks, companies and investors who own the options, analysts say — but improved prospects for the agreement haven't notably increased demand for them.

During the past two months, the price has stuck in a band between €19 and €24, following much wider fluctuations earlier in the year. Volume continues to grow: in the five markets, between 6 million and 10 million options are now sold every week, up from around 5 million a week in September.

Recent swings have reflected other climate-policy developments, says Marcel Hanakam of Frankfurt-based Climate Change Consulting. Reports in late September that the European Union might make aviation subject to emissions trading boosted the price, for example, and a court ruling that questioned the UK emissions allocation plan caused it to fall earlier this month.

Large companies in the European Union are allowed to emit a certain amount of carbon dioxide a year; if they require additional allowances they need to buy them on the emissions markets.