Requirements of a corporate sustainability job are outlined nicely on page 13 of this presentation which details the upcoming need for sustainability executives across all size organizations in order to stay competitive.  Wall Street will demand a sustainability focus so more of these jobs are certain to be created. http://www.slideshare.net/RThorne/HudsonGain-Sustainability-Study-20081015

This firm is also a recruiting and consulting firm that you may want to learn more about: http://careereco.com/wikis/job_search/sustainability-recruiters.aspx