BEIJING — China’s plans for 50 coal gasification plants will produce an estimated 1.1 billion tons of carbon dioxide per year and contribute significantly to climate change, according to a report released Wednesday by Greenpeace East Asia.

The plants, aimed in part at reducing pollution from coal-fired power plants in China’s largest cities, will shift that pollution to other regions, mostly in the northwest, and generate enormous amounts of carbon dioxide, the main greenhouse gas produced by fossil fuels, said the organization, which is based in Beijing.

If China builds all 50 plants, the carbon dioxide they produce will equal about an eighth of China’s current total carbon dioxide emissions, which come mostly from coal-burning power plants and factories, the organization said. Two of the plants have already been built as pilot projects, three more are under construction, 16 have been given the green light to be built and the rest are in various planning stages, according to the report.

Last September, the government announced a plan to alleviate air pollution in China’s notoriously smoggy cities. The plan would reduce coal use in the most populated areas by 2017.