BP (Oil) and Bayer (chemistry) are 2 and 3

Top Companies of the Decade BusinessWeek, Climate Group, and a panel of judges compiled this ranking based on total reduction of greenhouse gases (GHGs), results relative to company revenues, and management's leadership on environmental issues over the past ten years
1 DuPont
2 BP
3 Bayer
4 BT
5 Alcoa
6 IBM
7 Catalyst Paper
8 STMicroelectronics
9 3M
10 Iberdrola