[S]ustainability risk remains an amorphous idea, with companies, governments and the public still sorting out the ways it should be monitored and mitigated...Still, investors are increasingly interested in sustainability risk...a company with a good grip on sustainability will have grappled with issues ranging from human rights to local economic impact to workforce turnover...[There are] forces other than investor pressure leading to change – from a new generation of business leaders who question the laisser faire model, to employees asking that their employers demonstrate a more responsible approach to the environment...Customers can provide the impetus for change. [refers to Enron, Balfour Beatty]