Greenhouse gases are a tremendous challenge for all of us. I think, so that everybody's on the same page, greenhouse gases are created by the consumption of energy in any form. We consume primarily natural gas energy, and there is consumption of the off-gases from upgrading the fuel.
We continue to improve that ratio of consumption versus production of oil by applying new technologies and more capital investment. As an industry, we have reduced that greenhouse gas footprint by 40% in the last 20 years. I think that is three or four times better than the improvement in natural gas consumption or in carbon dioxide emissions or gas consumption by the automotive sector, which has been working to improve its gas mileage. So we're all in this together in terms of efficiency of energy and carbon dioxide production. We are spending probably more than any other industry and having greater improvements than any other industry, and we continue to do so.