Following the letter Nebraska Gov. Dave Heineman (R) sent to President Obama asking him to oppose the Keystone XL pipeline, former Vice President Al Gore wrote a blog post Wednesday night calling on Obama to reject the pipeline’s permit. “The answer to our climate, energy and economic challenges does not lie in burning more dirty fossil fuels — instead, we must continue to press for much more rapid development of renewable energy and energy efficient technologies and cuts in the pollution that causes global warming,” Gore wrote. The State Department released a report in favor of the project, saying the pipeline would have limited environmental impact. Critics say the report ignores key concerns.