Scientists have revealed through a new paper that amidst the global COVID-19 lockdowns across the world last year there was a temporary increase in global temperatures. This is because of the massive decline in ebmissions across the world. The higher the pollution, the cooler the planet and the lower the emissions, the warmer the planet.
According to the new research led by the National Center for Atmospheric Research (NCAR), the decline in emissions had an immediate, short-term effects on temperatures. Pollution cools the planet, so it makes sense that pollution reductions would warm the planet. Temperatures over parts of Earth’s land surface last spring were about 0.2-0.5 degrees Fahrenheit (0.1-0.3 degrees Celsius) warmer than would have been expected with prevailing weather conditions, the study found. The effect was most pronounced in regions that normally are associated with substantial emissions of aerosols, with the warming reaching about 0.7 degrees F (0.37 C) over much of the United States and Russia.
The new study highlights the complex and often conflicting influences of different types of emissions from power plants, motor vehicles, industrial facilities, and other sources. While aerosols tend to brighten clouds and reflect heat from the Sun back into space, carbon dioxide and other greenhouse gases have the opposite effect, trapping heat near the planet’s surface and elevating temperatures.
Despite the short-term warming effects, Gettelman emphasized that the long-term impact of the pandemic may be to slightly slow climate change because of reduced emissions of carbon dioxide, which lingers in the atmosphere for decades and has a more gradual influence on climate. In contrast, aerosols – the focus of the new study – have a more immediate impact that fades away within a few years.
The study was published in Geophysical Research Letters. It was funded in part by the National Science Foundation, NCAR’s sponsor. In addition to NCAR scientists, the study was co-authored by scientists at Oxford University, Imperial College, and the University of Leeds.