There have been at least three times that we have seen reductions in greenhouse gas (GHG) emissions in recent years. The COVID-19 pandemic is also expected to cause a decrement in emissions. The virus has caused a 17 percent reduction in atmospheric carbon emissions during parts of this year and may decrease CO2 emissions by 4.2-7.5 percent in 2020 compared to 2019. These estimates from the United Nations’ World Meteorological Organisation (WMO) are yet to be confirmed but they corroborate earlier data that shows the COVID-19 pandemic has driven down GHG emissions. This was initially observed in China as the first nation in the world to be stricken with the virus. As the virus spread around the world, we saw similar reductions in emissions in other countries. In previous years we have seen reductions in emissions correlated with economic crises and other factors. Some excellent data elucidating this trend comes from the International Geosphere-Biosphere Programme (IGBP). This organization launched a research programme dedicated to studying the phenomenon of global change. The data collected by the IGBP has been compiled in a table (see left) that helps us to seen to monitor year over year changes in GHG emissions.
A review of the IGBP data reveals that we have seen at least three years when emissions declined in recent years. Negative values can be seen in 1982, 1992 and 1996. The negative index values in 1982 reflect the demise of the Soviet Union. In 1992 carbon emission hit a 20-year low due to three factors: A mild winter, reduced demand for gasoline and, most significantly, a drop in coal-fired electricity generation because of historically low natural gas prices. The negative values in 1996 are due to a slowing economy associated with the Asian financial crisis.
However, we have also documented troubling historical trends following these reductions, particularly if they relate to a crisis. In 2011, the Global Carbon Project (GCP) published its annual analysis that showed an increase of global CO2 emissions of 5.9 percent in 2010 (a record for that time) as developed economies (China, USA, India, the Russia, and the European Union) resumed their emissions growth after a brief respite during the 2008-2009 Global Financial Crisis (GFC). This growth was attributed to increased fossil fuels and cement use which accounted for 52 percent of the total growth. The authors conclude that the global financial crises failed to move the global economy away from a high emissions trajectory. In 2010 atmospheric CO2 rose to 389.6 parts per million, representing not only the highest recorded levels in at least the last 800,000 years, but the highest annual growth ever recorded as of that date.
A review of emissions as they relate to significant economic events (1970’s oil crisis, the US Savings and Loans Crisis, the collapse of the Soviet Union, the Asian Financial Crisis, and the Global Financial Crisis) reveals that in times of crisis, countries maintain economic output by supporting less-energy intensive activities. These observations are related to easing of energy prices, government investment to stimulate economic recovery, and the effect of a decade of high economic growth in the developing world leading to rapid post-crisis return to high emissions.
While the Coronavirus lockdowns have reduced pollution, we continue to see perilously high levels of emissions. According to the WMO in 2020 we are likely to surpass the 410 parts per million of CO2 observed in 2019. We currently have the highest levels of CO2 in three and half million years. It should be noted that that 3.5 million years ago sea levels were 10-20 metres [32.8-65.6 feet] higher than they are today. The WMO reports that we have seen a 45 percent increase in radiative force (the cause of warming) since 1990 and increasing levels of atmospheric CO2 are responsible for four fifths of this effect.
The CO2 increase in 2020 will be less than it was in previous years but they are still expected to increase. There was a 2.6 ppm rise of CO2 from 2018 to 2019, and the rate of increase between 2019 to 2020 is expected to be about 0.08-0.23 ppm less than that.
Looking at these observations as well as those from the IGBP, it is clear that with only a few exceptions we have seen an almost uninterrupted increase in atmospheric carbon. This has been accompanied by steady increase in temperature and a steady decline in sea ice extent. Consistent increases are also evident on the climate index and the cumulative climate index.
The overall trend shows that CO2 levels are rising at a rate never before seen and this poses a very serious threat to our biosphere. The situation is undeniably perilous but there is reason to hope that the severe economic hardships associated with the Coronavirus, have upsides that may include a paradigm changing impact. It starts with increased support for facts and science based policy but also includes a surge in renewable energy and a decline in fossil fuels. Most importantly the pandemic is driving hopes that we will see an economic reset that will drive a transition to a low carbon economy.
However, it is far from certain that we will learn from this pandemic. What is certain is that reducing GHG emissions is becoming increasingly urgent as we teeter on the cusp of warming that could augur the collapse of civilization. If we are to act to reign in emissions within the remaining window of opportunity it is now or never.