Disclosure of climate change risks finally came to annual reports this year. So far, the picture is slightly cloudy.

The Securities and Exchange Commission approved its interpretive guidance for climate change disclosure on Feb. 8, when most year-end companies were already nearly finished with their Form 10-K filings for 2009—so dramatic changes in what companies are disclosing in this year’s reports have been rare.

Instead, companies are attempting new iterations of old disclosures made in previous years. And since nobody in previous years knew what good disclosure of climate change risk should look like, the result this year is disclosure that’s ...