CALGARY, Alberta (AP) - In the northern reaches of Alberta lies a vast reserve of oil that the U.S. views as a pillar of its future energy needs. China, with a growing appetite for oil that may one day surpass that of the U.S., is ready to spend the dollars for a big piece of it. The oil sands of this Canadian province are so big that they will be able to serve both of the world's largest economies as production expands in the coming years. But that will mean building at least two pipelines, one south to the Texas Gulf Coast and another west toward the Pacific, and that in turn means fresh environmental battles on top of those already raging over the costly and energy-intensive method of extracting oil from sand. Most believe that both will eventually be built. But if the U.S. doesn't approve its pipeline promptly, Canada might increasingly look to China, thinking America doesn't want a big stake share in what environmentalists call "dirty oil," which they say increases greenhouse gas emissions. Alberta has the world's third largest oil reserves, more than 170 billion barrels. Daily production of 1.5 million barrels from the oil sands is expected to nearly triple to 3.7 million in 2025. Overall, Alberta has more oil than Russia or Iran. Only Saudi Arabia and Venezuela have more. Alberta is one of the few places where oil companies can invest, as the majority of the world's oil reserves are controlled by national governments. Only 22 percent of the total world reserves are accessible to private sector investment, 52 percent of which is in Alberta's oil sands, according to the Canadian Association of Petroleum Producers. Canada's only major oil export market is the U.S. But with the product of oil sands and pipeline delivery to the U.S. under perennial clouds of environmental objections, and with Asian demand growing, this country wants to diversify its market, and China is eager to oblige. Sinopec, a Chinese state-controlled oil company, has a stake in a $5.5 billion plan drawn up by the Alberta-based Enbridge company to build the Northern Gateway Pipeline from Alberta to the Pacific coast province of British Columbia. Alberta Finance Minister Lloyd Snelgrove met this month with Sinopec and CNOOC, China's other big oil company, and China's largest banks. "They are sitting there saying if you need money, we've got money; if you need expertise, we've got that; whatever you need we've got," Snelgrove said. Alberta Premier Ed Stelmach said American government officials have expressed concern about a pipeline to the Pacific. They have raised it in terms of "Well, are you still going to be able to supply us?" he said. That fear may already have fallen aside. "There are people who still feel that one barrel of oil going from Canada to China could be one more barrel going to the United States. But those are people in the minority. It is a concern but it is not a big concern," said Wenran Jiang, a professor at the University of Alberta and a senior fellow of the Asia Pacific Foundation. Stelmach said the U.S. will remain Canada's primary oil customer. But aboriginal and environmental opposition to the Pacific pipeline is fierce. The opponents fear it will leak. The local member of Parliament, Nathan Cullen, says accidents are inevitable in the rough waters around Kitimat, British Columbia, where the pipeline will end. And no one has forgotten the Exxon Valdez oil spill of 1989, some 1,300 kilometers (800 miles) north of Kitimat. However, Canadian Prime Minister Stephen Harper, freshly and convincingly re-elected, is an oil man who has suggested he supports building the pipeline. Also, Calgary-based Kinder Morgan has plans to expand an existing pipeline route to Vancouver so that oil can be shipped to Asia. Critics dislike the whole concept of oil sands, because extracting the oil requires huge amounts of energy and water, increases greenhouse gas emissions and threatens rivers and forests. Keystone XL, the pipeline that would bring Alberta oil to Texas Gulf Coast refineries to serve the U.S. market, compounds the issue. Pipeline leaks can affect drinking water and sensitive ecosystems, the U.S. Environmental Protection Agency warns. In a letter to the State Department this month, it cited major pipeline spills last year in Michigan and Illinois, as well as two leaks last month in the Keystone pipeline, a 1,300-mile line owned by the same company that wants to build Keystone XL. The U.S. pipeline safety agency briefly blocked Calgary-based TransCanada from restarting the Keystone pipeline this month because of safety concerns. But Keystone XL could substantially reduce U.S. dependency on oil from the Middle East and other regions, according to a report commissioned by the Obama administration. It suggests that the pipeline, coupled with a reduction in overall U.S. oil demand, "could essentially eliminate Middle East crude imports longer term." The U.S. imports about half its oil. The biggest foreign supplier is Canada, at 23.3 percent, followed by Venezuela at 10.7 percent. The biggest Mideast supplier is Saudi Arabia, 10.4 percent. The report was made public ahead of President Barack Obama's meeting in February with Harper, who is urging Obama to endorse it. Environmental groups want him to reject it, seeing it as a test of Obama's will to fight climate change. The State Department, which must approve any pipeline entering the U.S. across an international border, has promised a decision by year's end. But Republicans on the House Energy and Commerce Committee want it by Nov. 1. Committee chairman Fred Upton, R-Mich., said the pipeline will create at least 100,000 jobs and that the U.S. needs Canadian oil. Michael A. Levi, the senior fellow for energy and the environment at the U.S. Council on Foreign Relations, said environmentalists are exaggerating the impact on the oil sands. "A lot of people have been convinced that this is the cutting edge of the climate change fight," he said. "In the end this is the equivalent to half a percent of U.S. emissions." He said the choice of pipeline was a critical decision in U.S-Canada relations and that turning down the Texas route would go over very badly in Canada. But David Goldwyn, a former State Department energy official who left this year to work as a consultant, said he's confident the pipeline to Texas will be approved, especially considering the potential for Middle East turmoil to disrupt supplies in the future. "I think it would be a huge waste of a great opportunity to provide supply security. We don't often get the choice of where we can get our oil from. In this case we get to choose Canada. That's an opportunity we shouldn't miss," he said in an interview. He saw no threat from Chinese inroads into Canada because there is more than enough oil for all concerned. By investing to boost Canadian production the Chinese "are growing the pie to meet their own demand. That's a whole lot better than mopping up supply from the existing pie and creating competition for resources," Goldwyn said. But China would almost certainly react badly to a rebuff. Alberta Energy Minister Ron Liepert fears Chinese investment will dry up should Canada not approve a pipeline to the West Coast. Zhang Junsai, China's ambassador to Canada, said his country is willing to invest heavily in Canada. He told The Associated Press that the fact that China's $300 billion sovereign wealth fund, China Investment Corp., chose Toronto as the venue for its first overseas office is a "very good sign." The fund invested $800 million in Calgary-based Penn West Energy last year and $1.5 billion in Canadian mining company Teck Resources in 2009. Apart having a stake in the $5.5 billion in the Northern Gateway pipeline plan, Sinopec paid $4.6 billion for a nine percent stake in Syncrude, Canada's largest oil sands project. And in 2009 PetroChina, Asia's largest oil and gas company, bought a $1.7 billion stake in Athabasca Oil Sands Corp. William Cohen, who was secretary of defense in the Clinton administration, said any Chinese-Canadian oil partnership must be done "with some diplomacy and care," in a way that isn't "a threat to the United States." Canada can do whatever it wants, but "Canada knows it has a very close and vital relationship with the United States. I'm sure there will be discussions," he said in Toronto after a public debate about whether China will dominate the 21st century. Eddie Goldenberg, chief of staff to former Prime Minister Jean Chretien, said in an interview that Canada should care less if some American officials are leery about Canada selling oil to China. "We're not the 51st state. It's not the business of the United States to decide where Canada sells its resources," he said.