Beijing officials issued the alert on Monday night to stem the smog and to show residents that the government was taking action. But the inconvenience it caused for most residents also seared the scope of China’s environmental crisis into the public’s consciousness, just as recent bouts of severe, multiday pollution — the dreaded rounds of “airpocalypse” — have done.

“I have to watch my child because there is no kindergarten today,” said Kan Tingting, 35, a manager of a cafe who stayed indoors with her 3-year-old daughter — one of some two million schoolchildren to remain at home Tuesday. “What bothers me the most is that my child may have a very negative view of nature. She loves nature much less than she would in a normal environment. I don’t want her to grow up thinking nature is ugly.”

In another corner of Beijing, a university lecturer, Wang Bei, was bunkered down at home with her 10-year-old son. “Air pollution is a huge problem that we ignored early on, while we concentrated on economic development,” she said. “Now we are paying the price for that. It only takes a second for someone to fall gravely ill, but it takes a long time to recover. Now China is that ill person trying to recover from air pollution.”

The current spell of bad air began Sunday. By Monday morning, the quality had deteriorated to what the United States labels a “very unhealthy” level. Still, it was not nearly as bad as the toxic cloud that afflicted the city in the final weekend of November, when the concentration of fine, deadly particulate matter in southern Beijing hit 40 times the exposure limit recommended by the World Health Organization.