The burning of fossil fuels is the main source of man-made CO2 emissions that contribute to global warming, and is closely related to the productive activities of mankind after the Industrial Revolution. Under the influence of the new crown outbreak, the global multi-industry shutdown, “epidemic reduction of man-made CO2 emissions” reports began to appear in the press: in February this year, According to a series of reports on the Ukranian Carbon Brief website, China’s CO2 emissions fell by a quarter in February from a year earlier; Emissions will be reduced by 8 per cent.
The impact of the outbreak on CO2 emissions has also attracted the attention of the scientific community. A recent study by Nature Climate Change, an international journal of natural sciences, found that global CO2-day emissions were 17 percent lower than the 2019 average by early April 2020. Another paper, led by Chinese scientists and published on the scientific literature preprint platform arXiv (https://arxiv.org), points out that global CO2 emissions decreased by 5.8% (542 Mt) in the first quarter of 2020, with industry and transportation contributing the most.
It is perhaps surprising that the new crown outbreak will contribute six times as much to the global CO2 emissions reduction sharply as in 2008, surpassing more social events in a century, including world war II.
So when did human monitoring of CO2 begin? How does the CONCENTRATION OF CO2 in the atmosphere normally change? As one of the main greenhouse gases, will reducing CO2 emissions under the influence of the outbreak slow global warming?
Global CO2 emissions are changing from the previous year, with the 2020 estimates shown in red. (Photo credit: International Energy Agency Global Energy Review)
Keelin Curve: EE-EMap for Atmospheric CO2 Concentration
When it comes to CO2 in the atmosphere, you have to mention a man named “Keeling” and his “Keeling Curve”. In 1953, a young man named Charles David Keeling began his postdoctoral career at Caltech, where he worked on extracting uranium from yellow rock for the nuclear industry. Like many unusual geniuses, Keeling is not interested in his original research project, but rather in the carbonate balance between surface water, limestone and atmospheric CO2. With the support of his mentor, he began using a sophisticated gas pressure gauge to measure CO2 in the atmosphere and acidified water bodies. From the california coast, Keeling stepped out of the rainforests of Olympic Island and into the mountains of Arizona, unaware that he was writing a history of human observation of atmospheric CO2.
Later, Keeling’s measurements caught the attention of experts from the U.S. Bureau of Meteorology and the Scripps Institution of Oceanography, who, with funding, purchased four infrared gas analyzers and installed one of them on Mount Monaroa on the Hawaiian island. One day in March 1958, Keeling wrote down a value of 313 ppm, the starting point for the Keeling Curve. Until now, the station has been updating atmospheric CO2 concentration data day by day, and today the number is more than 410 ppm.
Change characteristics of atmospheric CO2 concentration: rise in fluctuations
The continuous record of the “Keeling Curve” leads to two crucial discoveries: the continued rise in atmospheric CO2 concentrations caused by nature’s seasonal “breathing” and the burning of fossil fuels.
Every year, from May to September, everything in the northern hemisphere grows, and plants absorb CO2 through photosynthesis, causing atmospheric CO2 concentrations to decline, and after October, atmospheric CO2 concentrations gradually recover as temperatures in the northern hemisphere cool into winter. As Keeling puts it: “For the first time in human history, man has seen the breath of nature.”
Global CO2 emissions are changing from the previous year, with the 2020 estimates shown in red. (Photo: IEA Global Energy Review)
Keeling was awarded the National Science Prize in 2002 for its advanced scientific awareness and perseverance. In 2005, Keeling, who devoted his life to atmospheric CO2 monitoring, died, and in an era when mankind was not aware of global warming, it was Keeling’s innovation and persistence that opened the history of continuous direct observation of atmospheric CO2 concentrations.
Today, using CO2 records in polar ice cores, the “Keelin curve” has been extended to 800,000 years ago, and we know that during the cold ice age, the concentration of CO2 in the Earth’s atmosphere is about 200 ppm, even during the warmer inter-ice period, which was only about 280 ppm before human activity. Since the Industrial Revolution, the burning of fossil fuels has accelerated the release of CO2, and it is an indisputable fact that human influence on the environment has been made.
Charles David Keeling (Photo: Scripps Institute of Oceanography). Scientific research also requires the “life-long” spirit of craftsmanship.
Can the fall in CO2 emissions caused by the outbreak mitigate global warming?
Although nature’s “breathing” has seasonal fluctuations in atmospheric CO2 concentrations, the “Keelin Curve” records show that atmospheric CO2 concentrations continued to rise overall prior to the new crown outbreak. So will the decline in global CO2 emissions affected by this outbreak change this trend?
Based on the historical record of the “Keelin Curve” and combined with projections of man-made emissions and climatic conditions, the Met Office had predicted that the global CO2 concentration would increase by 2.80 ppm (?0.57) over last year by 2020, but if the 8 per cent reduction in global CO2 emissions under the influence of the new crown outbreak was taken into account, the projected increase in concentration shrank would be revised to 2.48 ppm – although the decline in global CO2 emissions has led to a decrease in CO2 concentrations this year. The concentration of CO2 in the atmosphere is still rising.
Observed and predicted atmospheric CO2 concentration smnby, curve represents seasonal changes, straight lines represent annual averages, red is the initial forecast of atmospheric CO2 concentration in 2020, and blue is a correction that takes into account the effects of the new crown outbreak. (Photo: Met Office)
Carbon dioxide is a major greenhouse gas, with a life span of up to two hundred years, and although the outbreak has led to a reduction in some CO2 emissions, it has a role to play. Therefore, the current increase in the global atmospheric CO2 concentration trend will not change, global warming will continue.
In addition, the annual global atmospheric CO2 concentration is also affected by climatic conditions such as El Ni?o. We know that CO2 is soluble in water, solubility and water temperature, and that the ocean, which accounts for 70% of the Earth’s surface, is a natural sink of CO2 (sucks co2 from the atmosphere) (read: store 93% of global warming energy, and the ocean is becoming the earth’s powder keg).
According to the National Climate Center on May 8: “Since November 2019, the equatorial Middle Eastern Pacific has entered and sustained an El Nino state, with the sliding averages of the Ni?o 3.4 index for five consecutive months, respectively, 0.6 c, 0.5 degrees C, 0.5 degrees C and 0.5 degrees C.” According to the national criteria for the El Ni?o/La Ni?a event, an El Ni?o event (weak intensity) has been formally formed”.
El Ni?o index. (Photo Source: National Climate Centre)
While several climate centers do not expect the weak El Nino event to last and will turn neutral this summer, the previously elevated Pacific sea temperature will somewhat affect the ocean’s ability to dissolve CO2 and offset some of the decline in CO2 emissions in the new crown outbreak.
Climate change remains grim, and humanity may face a watershed in the future world
Thus, the “black swan incident” of the new crown outbreak has limited impact on global warming, and we are still faced with a world of extreme weather, and international cooperation is the only option to adapt to and mitigate climate change.
The Paris Agreement aims to limit global warming to 2 degrees Celsius and to reduce that threshold to 1.5 degrees Celsius. Studies have shown that a 0.5-degree warming reduction can reduce the number of people exposed to extreme precipitation events in future global monsoon regions, the most pronounced in the fragile South African monsoon region, followed by the South Asian monsoon region and the East Asian monsoon region. As we focus on Africa, which is less resilient to climate change, another study shows that if global warming can be controlled at 1.5C by the end of the century, it can significantly reduce the frequency of extreme heat waves in Africa and affect droughts and floods here, with a significant difference of 0.5C for many of the living beings on this ancient land.
It’s not just Africa. Globally, all mankind is experiencing the test of climate change, and the epidemic has had a profound impact on all aspects of human society, and the uncertainty of international cooperation has increased. How will the world economy recover after the outbreak as CO2 emissions are reduced by reduced global warming? Perhaps that time, is the real human beings to face the choice and test.