But Obama faces a reality that many of these groups seem slow to recognize: While the 20th - century toolkit preferred by
traditional environmentalists — litigation, regulation and legislation — remains vital to limiting domestic pollution risks
such as the oil gusher, it is a bad fit for addressing the building human influence on the climate system, which is driven now mainly by a surge in emissions mostly outside United States borders in countries aiming to propel their climb out of poverty on the same
fossil fuels that generated much of our affluence.