For three days at the end of May — the 24th through the 26th — scores of world business leaders gathered in Copenhagen to discuss ideas and options leading up to the UN climate conference to be held in the same city in November, when a treaty to supplant and extend the Kyoto accords with the promulgated for ratification by the nations of the world, a consummation devoutly to be wished.

Finally, it appears, the deniers are moving to the edge of the debate. Slowly the delayers — the obscurantists and obstructionists and obnoxionists — are melting away like (dare one say it?) polar ice caps. The traditional (reasonable) CEO request of politicians is “Be clear, be consistent, and leave us room to make a profit.” It looks like they are about to get their wish:  People who make policy, create markets, and write regulations — and global climate action will require all three — at last have an opportunity to make a world-saving difference, and give businesses a way to make plans.

Companies need a way to think about this soon-to-be-carbon-constrained world, and, frankly, few of them have thought much about it — some from active resistance, some from inattention. At a gathering of executives a few months ago, I heard one whose entire understanding of climate change was limited to replacing the light bulbs in her company’s offices and substituting tap for Fiji water. In a sense, you can’t blame her: this is one of those issues that requires an enterprise-wide framework and response: It’s a b board-level issue first and foremost.

Here are five questions every board should ask its CEO, only one of which has to do with light bulbs.

1. What impact will a carbon-constrained world have on our income statement and prospects for growth?
2. What are the implications for our balance sheet and risk profile?
3. What new opportunities might we have in a warming world and under a regime of carbon constraint?
4. How will our stakeholders be affected by carbon constraints, and how should we respond to them?
5. How can we shrink our carbon footprint?

Every CEO should be able to answer them, in detail and with plans. Every entrepreneur ought to be able to address them, too — because they will redraw the landscape for you, too.