Concerns over climate change have not been at the forefront of most chief executives' minds in recent weeks: the financial crisis and economic downturn have eclipsed all other issues.

While managers are worried about whether their businesses are sustainable economically, the question of whether they are sustainable environmentally seems less pressing.

Before the crisis wiped out other concerns, companies were increasingly eager to trumpet their environmental credentials. Large companies, including household names such as Wal-Mart and General Electric, Ford and Coca-Cola, HSBC and News Corporation, made pledges to cut their greenhouse gas emissions and lessen their environmental impact. What will happen to companies' environmental commitments when businesses are fighting for their survival? Will the pledges made in a sunnier economic climate be forgotten?

Talk to any of the companies that have taken a lead on environmental issues, and the answer is the same: no. Environmental sustainability is just as important in a downturn, they insist. ”Our goal is still to be one of the world's leading brands in corporate sustainability and we regard it as central to business strategy,” says Francis Sullivan, deputy head of corporate sustainability at HSBC.

“We continue our commitment to reducing our environmental footprint and implementing our sustainability risk policies. We also maintain that sustainability offers diverse business opportunities [such as investment in renewable energy].”