Hilcorp, Exxon and Conoco top greenhouse gas emitters, environmental groups say

- New report is based on data oil-and-gas firms submitted to U.S. on carbon dioxide and methane emissions
Listen to this article |
Hilcorp Energy Co., Exxon Mobil Corp., ConocoPhillips and Occidental Petroleum Corp., are the U.S. oil-and-gas industry’s top emitters of planet-warming greenhouse gases, according to a new report based on federal data.