Q: What’s the fastest way to give your company a black eye in today’s green-sensitive world?

A: Don’t report any environmental information, and especially don’t report greenhouse gas (GHG) emissions like carbon dioxide (CO2).

That’s how hundreds of companies ended up at the bottom of a new Green Rankings survey published by Newsweek magazine.

The key to getting top honors:

1. Create environmental metrics, like measuring pollution created, waste generated and GHG emissions released
2. Adopt programs to reverse these events, and
3. Report your progress.

That’s the approach adopted by hundreds of companies that scored well in the Green Rankings analysis. The top five companies are:

1. Hewlett-Packard for its strong programs to reduce GHG emissions
2. Dell for its commitment to rely on renewable energy
3. Johnson & Johnson for its commitment to climate change programs
4. Intel Corporation for its reliance on renewable energy purchases, and
5. IBM for its longstanding commitment to train employees on environmental awareness.

Newsweek spent a year studying the greeniness of the nation’s 500 largest companies and found that companies that set environmental goals — such as reducing their carbon footprint — and publicized the company’s progress in reaching these goals also scored better financially and ranked better than their peers.

The Newsweek story is here.

The magazine created its Green Rankings without the support or feedback of the companies. To do this, Newsweek used a program created by Trucost and NSF International to rate corporate green performances. The methodology is described here.

Many utilities are prominently at the bottom of the list, due to their release of GHGs when they burn coal to create electricity.

One utility, Duke Energy scored 490th in the Newsweek ranking. But this was calculated before Duke switched sides in the global warming debate. It now supports a cap-and-trade law to reduce GHG emissions. The energy company’s statement is here. It will be curious to see how Duke scores in next year’s rankings.

The bottom five are:

1. Consol Energy, basic materials
2. ConAgra Foods, food and beverage
3. Allegheny Energy, utility
4. NRG Energy, utility, and
5. Peabody Energy.

All of the listings are here.

The price tag: $92.8 billion! That’s the warning coming from a new analysis of what a GHG cap-and-trade program will cost companies.

Consultants Trucost and the nonprofit group, the Investor Responsibility Research Center Institute, project that the costs of buying all the GHG emission credits needed to operate under a cap-and-trade system would devastate the earnings potential of many companies.

The two groups reviewed likely costs on the companies listed in the S&P 500 index and found financial impacts vary widely. Some companies may see earnings potential drop 117% while others would suffer only 1% setbacks.

The utility sector would be hit hardest because it is the single largest emitter of carbon dioxide (CO2), the most prevalent GHG emission. Companies that buy power from these coal-fired power producers would see higher electric bills as utilities try to pass on these regulatory costs.

The analysis bases these predictions on the likely scenario that a GHG credit will sell for $28.24 a ton in 2012.

The Trucost report is here.

Trucost is also developing a product that helps state and local governments identify which companies and facilities to target for GHG control rules. Click here for details on its Comprehensive Area Assessment (CAA).