What public companies say -- and don't say -- about climate change matters. Just ask fast-food slinger Burger King Holdings Inc.

In May 2009, the company received some unwanted media attention after a few Memphis outlets posted signs reading: "Global Warming is Baloney." Burger King was quick to distance itself from its Memphis franchises' point of view on climate change, which CEO John Chidsey called "an overriding issue of importance" to the business community. Indeed, a year later, Burger King reported lower third-quarter earnings due in part to "adverse weather conditions" -- namely, the great blizzards of 2010, which prevented would-be customers from leaving their homes (and prevented Burger King locations from restocking burgers and fries).

Public companies have always been required to disclose material environmental risks to their operations. But it was never clear whether disclosure included the concept of climate change. In February, the U.S. Securities and Exchange Commission erased any doubt when it issued guidance directing public companies to improve their disclosure on climate change risks.

Under the new guidance, public companies now need to disclose material risks posed by climate change-related legislation (whether current or prospective); treaties and international accords; legal, technological, political and scientific developments; and environmental consequences, including severe weather conditions, rising sea levels, farmland arability, and water availability and quality. In other words, they will need to disclose almost anything related to climate change that could materially affect their business.

And with the first round of earnings reports following the release of the SEC's guidance now in, public companies -- and not just the usual suspects in oil and gas, utilities, transportation, insurance and agriculture -- are navigating climate change disclosure very cautiously.

Less than about 18% of public companies have included the precise terms "climate change" or "global warming" in their latest quarterly or annual reports filed with the SEC. And what disclosure there is -- which tends to be worded very generally -- has centered on the potential impact of climate change-related legislation.

This early testing-the-waters trend is understandable. Assessing climate change risk and developing adequate disclosure can be highly individualized and time-consuming work for public companies, many of which have operations spanning the globe. What's more, it reflects the uncertainty surrounding the prospects of a global climate change accord and federal cap-and-trade legislation in the U.S.

Not surprisingly, oil and gas, transportation, utilities and manufacturing companies have made the most extensive disclosures. For example, Xcel Energy Inc., Delta Air Lines Inc., United Parcel Service Inc. and other companies in these industries all have highlighted legislative and regulatory efforts at home and abroad to curb greenhouse gas emissions (for example, the Kyoto Protocol, the European Union's emissions trading system, proposed U.S. cap-and-trade legislation, potentially tighter Environmental Protection Agency emissions standards and California's Global Warming Solutions Act) -- as well as the material impacts these laws and regulations may have on current and future performance (for example, higher energy and fuel costs, increased capital costs associated with purchasing new technology and replacing older equipment, increased capital markets risk, and reduced demand for products and services).

Companies with less obvious exposure to legislation are also improving their disclosure, particularly with respect to the potential indirect impacts posed by climate-related supply chain disruptions and energy cost hikes.

Take specialty home goods retailer Williams-Sonoma Inc. In its most recent 10-K, the company disclosed the potential negative effects -- including increased fuel costs -- that climate change and related regulations may have on its ability to obtain quality merchandise from vendors and to deliver it to stores and customers quickly and in a cost-effective way.

Or Take-Two Interactive Software Inc., the software company responsible for the "Grand Theft Auto" video game series. In its 10-Q for the period ended Jan. 31, the company specifically pointed to the SEC's guidance in disclosing the potential risks posed by global and domestic efforts to reduce greenhouse gas emissions, noting that such laws could indirectly impact operations through increased energy, manufacturing or distribution costs.

Similarly, in its 10-Q for the period ended March 31, McDonald's Corp. -- a company you wouldn't necessary expect to be out in front of climate change disclosure because of the nature of its business -- warned of potential risks to its franchisees and supply chain from U.S. and foreign governmental authorities' increased focus on environmental matters, including proposed cap-and-trade legislation in the U.S.

Public companies are also improving their disclosure on the potential risks posed by the environmental consequences of climate change. And with good reason. Although perhaps not caused by climate change, the April eruption of Iceland's Mount Eyjafjallajökull confirmed that changes in the natural environment can severely disrupt global business. It makes sense then that recent climate change disclosure appears to be particularly focused on the potential for increasingly severe weather patterns to disrupt supply chains, reduce demand for certain goods and services, and harm physical assets.

To be sure, insurance companies are making absolutely clear in their public filings that increasingly unpredictable, severe and wide-reaching weather conditions -- including hurricanes, tornados and fires -- could impact those companies' exposure on the policies they underwrite.

But less obviously, restaurant chain McCormick & Schmick's Seafood Restaurants Inc. warned in its 10-Q for the period ended March 27 that more severe weather conditions could affect the price or availability of quality seafood and beef, and thus materially limit its ability to offer a diverse, reasonably priced menu. And Ultimate Escapes Holdings LLC, which operates a family of luxury destination club offerings, disclosed in its most recent Form 10-K that global-warming-induced extreme weather could limit travel by club members and reduce the desirability of some of the company's properties, such as those located on beaches or in skiing areas.

For its part, Pantry Inc. -- which operates 1,649 convenience stores in the Southeast, including many in coastal areas -- also warned in its quarterly report for the period ended March 25 that a rise in sea levels and increasingly frequent and powerful storms could lead to reduced demand for the company's products, property damage and relocation costs.

Of course, these disclosures are only part of the story. The SEC's guidance also creates valuable opportunities to enhance companies' environmental reputations and thus increase their profits.

Indeed, recent filings with the SEC indicate that companies are luring investors by touting their "green" records. For example, big-box retailer Best Buy Co.'s most recent 10-K highlights its efforts to increase energy efficiency in its U.S. stores, to sell more energy-efficient products and to recycle products through a nationwide consumer electronics take-back program.

Similarly, home improvement giant Home Depot Inc.'s most recent 10-K also discloses the company's efforts to reduce emissions from its domestic supply chain, as well as the implementation of an "Eco Options Program," which allows customers to identify more environmentally friendly products sold in Home Depot stores.

If new rules and the prospect of a better bottom line don't convince companies to address climate change disclosure, consider that shareholders want improved disclosure. Since the release of the SEC's guidance, the Investor Network on Climate Risk has counted a record 95 climate change-related shareholder resolutions with 82 companies in the U.S. and Canada (a 40% increase from last year).

Whatever the reason public companies make additional climate change disclosures, they would do well to guard against "box-checking." In the context of private securities litigation, when a public company makes forward-looking statements, it may be insulated from liability if it also provides cautionary language -- caveats that tell potential buyers and sellers that rosy forecasts might not turn out to be so rosy after all.

But that cautionary language only saves the day if it's meaningful and specific -- not boilerplate. So, you'd have to wonder about the effectiveness of disclosure for a company that includes very general language about climate change or, on the other hand, identifies climate change as having the potential to negatively impact its business plan if it has no exposure to climate change issues at all.

Still, as climate change disclosure evolves, it makes sense for public companies to get out in front of the issues. By making meaningful disclosure on the risks associated with climate change, public companies may send a strong signal to investors about their commitment to robust compliance with the federal securities laws and to corporate environmental sustainability. In other words, improved disclosure on climate change could leave companies seeing green in more ways than one.

Michael A. Mugmon is a counsel in the securities litigation and enforcement group at Wilmer Cutler Pickering Hale and Dorr LLP in Palo Alto, Calif.