Business Green: The not-for-profit Environmental Investment Organisation (EIO) is to launch a carbon ranking of the world’s largest companies with the aim of helping fund managers build carbon emissions into their investment decisions. The Environmental Tracking (ET) Carbon Rankings Index could be signed up as a live investment index by Standard & Poors if fund managers indicate their backing for the initiative. Indexes — of which the FTSE100 is probably the best known in the UK — rank …