Brace yourselves for the really big news coming out of the Copenhagen conference. It’ll be your corporate customers that force you to address climate change, not EPA or Congress.

Yes, EPA will regulate the largest greenhouse gas (GHG) emitters, mostly coal-fired power plants and large industrial facilities that release more than 25,000 metric tons a year of those global warming bad guys.

But that doesn’t mean smaller companies are off the hook, not at all.

The challenge ahead for small businesses will come from your big corporate customers — from auto makers, food and beverage companies, electronics manufacturers, and giant big-box retailers. They’re counting on you to cut your direct and indirect GHG emissions so they can claim credits for reducing their corporate carbon footprints.

Wal-Mart’s already made waves with its plan to create a Sustainability Index to rate the greeniness of all the products it sells. But other companies are also planning to green their supply chains.

For example, Coca-Cola’s announced this bombshell at the Copenhagen conference: It will reduce its own corporate carbon footprint by requiring Coca-Cola suppliers to reduce their GHG emissions. This means suppliers will have to account for their GHG emissions created during manufacturing, distribution, use and disposal of the products they sell to Coca-Cola.

The company was one of many corporations hosting booths in Copenhagen urging conference delegates to come up with an agreement that commits every country, and therefore every company, to reduce their GHG emissions, according to a report in the Los Angeles Times.

The paper reports that the companies went to Copenhagen to call for huge investments in clean, renewable power from solar and wind power to offset the rising costs of coal-fired electricity.

This comes as Coca-Cola’s UK operations and Unilever both warned that failure to put a cap on emissions will put a huge dent in their profits. The U.K’s Telegraph reports that the two companies will avoid this by significantly reducing their GHG emissions.

Meanwhile, Coca-Cola is doing what it can to reduce its direct GHG emissions.

It plans to stop using GHG refrigerants in its nine million vending machines around the world. The company says it will eliminate 100% of vending-machine GHG emissions by switching to hydrofluorocarbon-free refrigerants by 2015.

Tags: Coca-Cola, GHG emissions, Sustainability Index, Unilever, Wal-Mart