WASHINGTON—Emphasizing the numerous ecological benefits of blocking the proposed legislation, experts confirmed Wednesday that President Obama’s decision to veto the Keystone XL pipeline bill should buy the environment an additional three or four hours of viability. “Given the negative impact that this project could have had on the planet, we believe that the president’s efforts have successfully pushed back the complete breakdown of global ecosystems from about 3 p.m. to possibly 6:30 p.m. on the final day of ecological stability,” said Peter Grant of the Brookings Institution, adding that, by forestalling the construction of an oil pipeline that threatened to degrade air quality, interrupt species migration, and contribute to global warming, the White House had extended the era in which the earth can sustain life by as many as 300 minutes. “While the suspension of this project will do little to reverse the current damage to our environment, we can say with confidence that we’ve definitely delayed the complete destruction of nature by about the length of an afternoon.” At press time, Grant confirmed that the announcement of a new plastics manufacturing plant in Shanghai had cut their estimate in half.