He is a strong proponent of personal carbon trading (and specifically personal carbon allowances, a concept he helped develop).

All the named companies announced temporary or permanent shut-downs in recent weeks - just after this year's carbon allowances were handed out by February 28.

But the price of carbon allowances has remained too low to give companies enough incentive to start reducing their emissions.

Under EU regulations, airlines that fail to pay carbon allowances can be fined €100 per tonne of carbon dioxide.

So long as airlines file the appropriate paperwork, they'll be given 85% of their carbon allowance for free.

It purchased 1,000 short tons of carbon allowances.

So-called "carousel fraud" can be committed on any goods, but carbon allowances are particularly susceptible because they are high value, intangible and easily traded between different countries.

The price of a carbon allowance would go up because supply would decline while demand stays constant (assuming a positive growth rate for energy consumption).

I want to raise the issue of personal carbon allowances.

Starting in January 2012, international flights operating to and from the EU will be required to pay for carbon allowances for emissions for the entire flight.