In the past month, the world has witnessed one of the largest financial and economic upheavals in a generation. The fallout may have been most immediately felt on Wall Street, but the effect on energy, and perhaps even the environment, will also be profound.

Christophe de Margerie, chief executive of Total, the French oil company, who usually argues for governments to get out of the way of those trying to bring enough energy to the market to satisfy demand, this week said recent events meant lawmakers needed to consider extending a helping hand to environmentally friendly energy sources and technologies made uneconomical by falling oil prices.