As nations rush to ship vast new stores of natural gas across oceans, the climate change implications of the fuel are coming under increased scrutiny.

Perhaps nowhere is the debate so intense as in British Columbia, a province in western Canada where there are plans to export large quantities of natural gas to Asia. Environmentalists fear that the production and processing of the gas for export could upend the province’s aggressive climate change policies, which include an emissions-reduction goal and an unusual carbon tax system.

If facilities to export the gas are built, they “will make it virtually impossible for British Columbia to meet its greenhouse gas targets,” said Kathryn Harrison, a professor of political science at the University of British Columbia. For a province that has been a leader on climate change issues, she added, “that’s a huge change of direction.”

It is difficult to know exactly how British Columbia’s natural gas boom will affect its climate goals and policies, although the province’s government has promised to develop the resource in the most environmentally friendly way possible. What is clear is that British Columbia is a case study of competing priorities — determination to battle climate change on the one hand, and eagerness to take advantage of a job-creating energy bonanza on the other.

Six years ago, when the province began imposing a carbon tax, no drilling boom was in sight. The comprehensive tax was the first of its kind in North America, and environmentalists have hailed it as a relative success because greenhouse gas emissions fell after it was enacted, although other factors such as an economic slowdown were also at work. The province also established a goal of reducing greenhouse gas emissions by 33 percent from 2007 levels by 2020, although Dr. Harrison said the objective was “not on track.”

Shortly after the climate moves came into effect, a drilling technique called hydraulic fracturing unearthed new deposits of natural gas in British Columbia. Hydraulic fracturing, or fracking, deploys a mix of water, sand and chemicals at high pressure to release gas or oil trapped in rocks. Soon, the province’s fields began producing copious amounts of gas, and production rose about 40 percent from 2008 to 2013. But drillers had trouble selling the gas to one of their mainstay markets, the United States, because of a parallel American gas boom.

So British Columbia began looking to export its surplus to Asia. Eager buyers are at hand. China, which is struggling with air pollution, is eager to find substitutes for coal in its power plants, and Japan wants replacements for nuclear power. Large companies lined up to build multibillion-dollar gas export facilities in the province. Thirteen such facilities are now planned, according to the provincial government, but not all are likely to be built.

Drillers say that the world should welcome the boom, partly because it will help China move away from coal, which burns less cleanly than natural gas. Environmentalists counter that the calculus is more complex, because natural gas could take the place of renewable energy that nations like China and Japan also want to build.

Environmentalists also warn of leaks from natural gas production and pipeline facilities, which can send the potent greenhouse gas methane into the atmosphere. Industry representatives say that British Columbia’s standards for reducing methane releases are already high.

Much debate in British Columbia centers on the 13 facilities planned to export natural gas. These facilities transform natural gas into a liquid so the fuel can fit compactly onto ships. The process of liquefying the gas has two basic parts, according to Tom Rufford, a lecturer at the School of Chemical Engineering at the University of Queensland in Australia. First, the facilities remove contaminants such as carbon dioxide, hydrogen sulfide, butane and water. Then, acting like giant refrigerators, they cool the gas to minus 258 degrees Fahrenheit so that it becomes liquid. The liquefied natural gas, or L.N.G., then gets loaded into tanks for transport.

The plants that liquefy the gas are generally powered by natural gas. The energy needed to remove contaminants and liquefy the gas can amount to roughly 10 percent of the energy contained in the gas produced by the plant, Dr. Rufford said. He added that the facilities were “very efficient to start with, compared to some other industrial processes,” like coal-fired power plants.

Some environmental groups in British Columbia, such as Clean Energy Canada, want the facilities that liquefy the gas to use electricity derived largely from wind farms and local hydroelectric facilities for power, instead of mechanical energy and electricity from on-site natural gas-fired turbines. One relatively small proposed facility, called Woodfibre L.N.G., plans to use grid electricity rather than gas.

But some in the industry say that using grid electricity — which in British Columbia is largely made from hydropower — is impractical. Greg Kist, president of Pacific NorthWest L.N.G., a proposed $11 billion liquefaction facility majority owned by the Malaysian oil and gas giant Petronas, said his project planned to use gas, rather than electric power from the grid, because of the substantial energy requirements of the plant and the time frame in which power is needed.

“There’s very limited sources of power at that scope and scale in order to provide power for the facility,” he said. His plant would process natural gas that is relatively free of contaminants like carbon dioxide — one of several measures that will save energy, he said. The facility could begin construction next year.

Rich Coleman, British Columbia’s deputy premier and minister of natural gas development, was unavailable for an interview. But a ministry representative said in an email that the province’s carbon tax leadership would guide its decisions on liquefied natural gas. “The province is working to ensure B.C.’s L.N.G. operations are the cleanest in the world. Discussions are taking place with industry now to make this a reality.”

Environmentalists are skeptical. A report last year from Clean Energy Canada estimated that typical liquefied natural gas facilities in British Columbia would produce almost three times as much carbon pollution per unit of liquefied gas as a facility in Norway and another in Australia, which the report cited as global leaders. (The figures include the production and piping of natural gas as well as the process of turning it into a liquid.)

But gas producers say that British Columbia’s carbon policies will influence their efforts. “I think B.C. is and will continue to be a leader in many aspects of environmental policy,” said Dave Collyer, president of the Canadian Association of Petroleum Producers. Natural gas, he said, would fit into that framework.

^{Source: Galbraith, Kate. "For a Canadian Province, Gas Boom Presents a Conundrum."The New York Times. The New York Times, 28 May 2014. Web. 06 June 2014. <http://www.nytimes.com/2014/05/29/business/energy-environment/for-british-columbia-gas-boom-presents-a-conundrum.html?_r=0>}