Economic slowdown from Covid-19 will not replace action to tackle climate change
Efforts to combat the coronavirus pandemic have reduced economic activity and contributed to local improvements in air quality. But it is too early to assess the impact on greenhouse gas concentrations that are responsible for long-term climate change. Carbon dioxide levels at key observation stations this year were higher than last year.

According to the World Meteorological Organization (WMO), any reduction in emissions from the economic crisis caused by COVID19 does not replace concerted action to combat climate change.
"It would be irresponsible to downplay the enormous global health problems and deaths caused by the COVID19 pandemic," said WMO Secretary-General Petteri Taalas. "But now is the time to think about how to use economic stimulus packages to support a long-term transition to more environmentally friendly and climate-friendly practices of doing business and personal life."

"Past experience shows that reductions in emissions during economic crises are followed by rapid growth. We need to change this trajectory, " he said.

"The world needs to demonstrate the same unity and commitment to tackling climate change and reducing greenhouse gas emissions as containing the coronavirus pandemic," he said. "Failure to mitigate the effects of climate change could lead to more lives and economic losses in the coming decades," he said.
China's isolation and contraction in economic activity has led to a 25% reduction in CO 2 emissions in four weeks, according to analysis for Carbon Brief.

The WMO Global Atmosphere Watch coordinates high quality long-term global observations of greenhouse gas concentrations. Emissions are what gets into the atmosphere. Concentrations represent what remains in the atmosphere after a complex system of interactions between the atmosphere, biosphere, lithosphere, cryosphere and oceans.

Carbon dioxide remains in the atmosphere and oceans for centuries. This means the world is committed to continuing climate change regardless of the temporary drop in emissions due to the coronavirus epidemic.
According to the US National Oceanic and Atmospheric Administration, the monthly average atmospheric CO 2 content at Mauna Loa Observatory in Hawaii was 414.11 ppm, up from 411.75 ppm in February 2019. Mauna Loa is the world's longest continuous observing and monitoring station for the Global Atmosphere Watch Network. At another monitoring station, Cape Grim in Tasmania, CSIRO reported average CO 2 levels in February at 408.3 ppm, up from 405.66 ppm in February 2019.

About a quarter of total emissions are absorbed by the oceans. Another quarter is taken up by the terrestrial biosphere, including forests and vegetation which act as carbon sinks. Naturally, the terrestrial biosphere absorbs the same amount of CO 2 as it emits during the year in the seasonal cycle. Therefore, global average CO 2 levels usually increase until April / May.
This natural effect is much larger than the emission reductions associated with the recent economic slowdown. Thus, it is too early to draw firm conclusions about the significance of this economic downturn in relation to the concentration of greenhouse gases in the atmosphere. According to a study published in the journal Nature Climate Change, behind the global financial crisis of 2008−2009. This was followed by significant increases in emissions in emerging economies, a return to higher emissions in developed countries, and an increase in fossil fuel use in the global economy.

In 2018, molar fractions of greenhouse gases reached a new maximum, while the world average molar fractions of carbon dioxide (CO 2) were 407.8 ± 0.1 parts per million (ppm), methane (CH 4) — 1869 ± 2 parts per billion ( ppb) and nitrous oxide (N 2 O) at 331.1 ± 0.1 ppb. Preliminary data shows that greenhouse gas concentrations continued to rise in 2019.
Air quality

Observations by NASA and the EU's Copernicus Atmospheric Monitoring Service (CAMS) showed that nitrogen dioxide (NO 2) levels were significantly reduced during isolation in China. In Italy, CAMS reports a gradual decline trend of about 10% per week over the past four to five weeks. It should be noted that reductions in NO 2 are typically observed every spring in northern Italy due to reductions in emissions from residential heating and due to meteorological conditions.

Nitrogen dioxide is highly weather dependent and can vary greatly due to wind direction and speed. It is a gaseous air pollutant produced by the combustion of fossil fuels at high temperatures, harmful to human health and a precursor of near-surface ozone which has adverse effects on human health, ecosystems, and is also a short-term factor influencing the climate. NO 2 usually remains in the atmosphere for less than a day before precipitating or reacting with other gases in the atmosphere.

According to raw data, ground-level ozone measurements at the Global Atmosphere Watch station in Monte Cimone, which dominates the Po Valley in northern Italy, show a decline in March 2020. According to the Italian Consiglio Nazionale delle Recerche and the Institute of Atmospheric and Climate Sciences, it is too early to draw firm conclusions about the significance of this for greenhouse gas concentrations.

The concentration of solids is also reduced. According to the World Health Organization, PM 2.5 is one of the most important air pollutants in terms of health effects.