China will work to clear its skies by increasing investment in clean energy and punishing polluters, Premier Li Keqiang said Sunday in comments aimed at mollifying public anger over chronic smog. Swathes of northern China were blanketed under toxic smog this winter, affecting more than 100 million people and forcing government agencies to take emergency measures to curb pollution. "Environmental pollution remains grave, and in particular, some areas are frequently hit by smog," Li told delegates to the rubber-stamp National People's Congress (NPC) in opening its annual session. But "we will make our skies blue again", he said in his annual state-of-the-nation speech. Pollution has plagued China for years, with the dramatic fouling of the country's air, water and soil representing the dark side of breakneck economic growth that has lifted hundreds of millions out of poverty. Li listed a series of measures China will take this year to help clear the air, including upgrading coal-fired power plants to make them less polluting, reducing coal-fired heating, and implementing "round-the-clock monitoring" of industrial pollution. He said China would "basically" scrap all high-emission vehicles and pursue a three percent cut in emissions of sulfur dioxide and nitrogen oxide — key components of the country's toxic smog. "Faster progress in work to improve the environment, particularly air quality, is what people are desperately hoping for," Li said. China also will decrease its energy consumption per unit of GDP by 3.4 percent and reduce coal-fired power capacity. China has long promised to clean up its act, but the pledges have taken a back seat to ensuring rapid economic growth, which the government sees as critical for guaranteeing social stability. "Environmental issues are the most important because this affects people every day and leaves problems for the next generations," Chang Chunbun, a NPC delegate from Hong Kong, told AFP. "To solve pollution the authorities have to add power behind their laws to better enforce environmental protection policies." The ruling Communist Party is seeking to make a difficult transition away from dependence on heavily polluting industries to a more service-oriented economy fueled by consumer demand. Last year GDP grew 6.7 percent, the slowest rate in a quarter of a century, and Li on Sunday lowered the growth target to "around 6.5 percent" for 2017. Maintaining the desired growth rates has so far meant spinning up the output of goods like steel, coal and cement, whose production is heavily polluting. But the government is increasingly having to balance its concern over an economic slowdown with fears of a public backlash over environmental pollution. In recent months, police have cracked down on protests sparked by pollution in several major cities and moved to censor complaints about bad air online.