James Conca, geochemist, energy expert: America has over 2 million miles of oil and gas pipelines. Almost half are 50 years old. Over 2,000 miles of pipeline are 100 years old. These pipes have been subjected to pressure and weather-related stresses for a long, long time. Many must be replaced, or at least upgraded. With oil production increasing, the number of refineries decreasing, and capacity concentrating in ever fewer places, pipeline transport is not going to decrease. And there is no better alternative. So it is inevitable that we will build more pipelines with, hopefully better and better technologies, but we also must better maintain the ones we have, eventually completely replacing them.