Anglo-Dutch conglomerate Shell, and Elsam, Denmark’s largest electricity generator, have traded carbon emission permits with each other, the first time such a trading link has been established. The UK and Denmark have the only two government-backed trading schemes in existence so far.

Shell has taken over Danish allowances from Elsam, which it will use to meet the mandatory pollution targets applicable to its Danish operations, in return for UK allowances that will enable Elsam to mop up its emission surpluses in a form that it can carry forward into the UK scheme due to last until 2006, or trade on the UK market.

Although the volume of permits being traded is not great, its significance is that it establishes the possibility of such trading even in the absence of a formal mechanism for interchange between national schemes.