But Greenpeace resisted Shell's attempts to negotiate an end to the protest. Mike Hudema, one of the Greenpeace leaders who chained himself to a massive dump trunk, said they wanted to send a message to world leaders on the environmental damage being caused by giant oil sands projects. "To send a very strong message to President Obama and Prime Minister Harper that climate leaders don't buy tarsands," he said. Harper visits the White House on Wednesday. He is eager to protect the oil sands industry which has spurred a booming economy in western Canada in recent years. Environmental groups want Obama to get tough with Canada over the issue, but the president wants to reduce America's reliance on Middle East oil and has said he would like to work with Canada on developing carbon capture and storage to help deal with the massive emissions from the sands as well as the U.S. coal industry. The new, largely unproven technology would bury harmful emissions underground. Harper said in Parliament on Wednesday that the U.S. coal industry is 40 times the size of the oil sands. Harper also noted the oil sands are a huge source of jobs in Canada and said they are working with the Obama administration on a clean energy dialogue.