Even for those at the top, there was room for improvement on the Climate Counts scorecard, put together by a nonprofit group organized by the New England-based environmental entity Clean Air-Cool Planet and Stonyfield Farm, a US organic yogurt maker that placed sixth on the list, with 63.

"It's not enough to recycle paper and change lightbulbs," said Gary Hirshberg, Stonyfield Farm's chief and chair of Climate Counts. "We need to significantly reduce our carbon footprint ... Nobody deserves, or for that matter is getting, an A."

Stonyfield offsets 100 percent of its carbon emissions from manufacturing, Hirshberg said, but it needs to do more with renewable energy to cut the greenhouse gases that spur global warming.

The survey ranked the 56 companies chosen for their popular household use among mainstream consumers in North America and Britain, and for leading their respective sectors, from electronics to fast food.

CLIMATE-CONSCIOUS ELECTRONICS

Companies in the electronics/computer sector did well in addressing climate change compared with media and Internet companies, the survey found, with six of the 12 studied scoring above 50.

Besides Canon, these were International Business Machines Corp., Toshiba Corp., Motorola Inc., Hewlett-Packard Co. and Sony Corp. Dell Inc., Hitachi Ltd., Siemens, Samsung Corp. and Nokia were all in double digits and Apple Inc. scored only 2.

Food services as a sector was worst in terms of climate change impact, with none of the six scoring above 50 and three with a zero rating. Starbucks Corp. ranked highest in this group, with 46, followed by McDonald's Corp., at 22. Yum Brands Inc. -- which includes Kentucky Fried Chicken and Taco Bell -- scored a 1.

The rankings were based on 22 criteria that roughly broke down into four categories: how well a company had reviewed its global warming impact, how much it had reduced that impact, how much it supported public policies that encourage this reduction and whether the company made this information available. The amount of carbon reduction was weighted most heavily, worth a possible 56 out of 100 points.

Hirshberg and others on a telephone news conference announcing the scorecard stressed that this was seen as a "snapshot" of companies' progress. But it was also supposed to work for consumers who want to make an environmentally sound choice.