As cities and, in some instances, entire nations are weathering the pandemic under lockdown, Earth-observing satellites have detected a significant decrease in the concentration of a common air pollutant, nitrogen dioxide, that enters the atmosphere through emissions from automobiles, trucks, buses and power plants.
The decline, seen in China and Europe, correlated with strict on-the-ground social-distancing steps. Air emissions will significantly damage human health, the International Health Organisation calculates that illnesses from exposure to air pollutants — including stroke, cardiac disease, and respiratory diseases — kill around 4.2 million people a year.
The ozone layer has also started to repair itself. The loss of ozone in the Arctic reached a “breaking amount” in March, the highest since 2011, but the breach has now closed the United Nations. On Friday, the World Meteorological Organisation (WMO) reported. The northern hemisphere springtime anomaly was caused by ozone-depleting chemicals remaining in the environment, and icy winter in the stratosphere, WMO spokesperson Clare Nullis told a U.N. Briefing from Geneva. Less noise emission is no question necessary for many animals.
Michelle Fournet, a marine ecologist at Cornell who studies acoustic ecosystems, plans to place underwater microphones off the coast of Alaska and Florida, where she has observed bump back whales and other marine life, to explore how the seas have changed in the absence of noise from cruise ships when the industry is suspending operation worldwide.
“Just pulling those cruise ships out of the water is going to reduce the amount of global ocean noise almost instantaneously,” Fournet said. Research has shown that ambient noise from ships and other maritime traffic can increase the rates of stress-hormone in marine creatures which may influence their reproductive performance. Whales have also demonstrated that they can respond to the sound, pausing to sing while container ships are approaching and resuming as they are going inland.