Do investors care if the companies benefiting from their dollars are contributing to global warming? Increasingly, the answer may be yes: Global warming is the fastest-growing resolutions category tracked by the Investor Responsibility Research Center and the Social Investment Forum, according to data released last week. So far this year, 18 global warming resolutions have been filed by shareholders — as compared to seven in all of 2001. Most of the resolutions ask corporations to disclose estimated greenhouse gas emissions of their operations and products, as well as an assessment of the costs of reducing emissions. The resolutions are then sent to investors in publicly traded companies, who vote on the issues. The resolutions are toothless, because they are almost always opposed by management and are not binding even if passed — but they do create public-relations hassles for companies and can provide the necessary incentive for companies to negotiate with activists.