A Chinese scientist said that the smog situation in the country is so bad that it resembles a "nuclear winter," preventing plants from producing energy from the sun’s rays via photosynthesis, and presenting a possible disaster for the country’s food supply. According to the Guardian:
Beijing and broad swaths of six northern provinces have spent the past week blanketed in a dense pea-soup smog that is not expected to abate until Thursday. Beijing’s concentration of PM 2.5 particles, those small enough to penetrate deep into the lungs and enter the bloodstream, hit 505 micrograms per cubic metre on Tuesday night. The World Health Organisation recommends a safe level of 25.
New studies suggest that Chinese agriculture will see conditions "somewhat similar to a nuclear winter" if the smog continues, said He Dongxian, an associate professor at China Agricultural University. In one experiment, she germinated some seeds under artificial light in a lab, and others in a Beijing greenhouse. The former sprouted in 20 days, the latter took more than two months. "They will be lucky to live at all," He told the South China Morning Post newspaper. "Now almost every farm is caught in a smog panic," she added.