Are We Already Above 3 C and Nearing 4 C Temperature Rise? (Nov. 27, 2020)
There is no time to lose
Carbon dioxide levels continue at record levels, despite COVID-19 lockdown, the WMO reports. The increase in carbon dioxide from 2018 to 2019 was larger than that observed from 2017 to 2018 and larger than the average annual growth rate over the last decade.
The rise has continued in 2020. The lockdown did cut emissions of many pollutants and greenhouse gases, but any impact on carbon dioxide levels - the result of cumulative past and current emissions - is in fact no bigger than the normal year to year fluctuations.
“Carbon dioxide remains in the atmosphere for centuries and in the ocean for even longer. The last time the Earth experienced a comparable concentration of CO₂ was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now. But there weren’t 7.7 billion inhabitants,” said WMO Secretary-General Professor Petteri Taalas.
“The COVID-19 pandemic is not a solution for climate change. However, it does provide us with a platform for more sustained and ambitious climate action to reduce emissions to net zero through a complete transformation of our industrial, energy and transport systems. The needed changes are economically affordable and technically possible and would affect our everyday life only marginally. It is to be welcomed that a growing number of countries and companies have committed themselves to carbon neutrality,” he said. “There is no time to lose.”
Above image illustrates the steep rise in methane, compared to carbon dioxide and nitrous oxide. Levels of carbon dioxide, methane and nitrous oxide reached new highs in 2019, reports the WMO. Carbon dioxide (CO₂) rose to 410.5 ppm (148% of its pre-industrial level), methane (CH₄) to 1877 ppb (260% of pre-industrial) and nitrous oxide (N₂O) to 332.0 ppb (123% of pre-industrial).
So, given that there's no time to lose, why mention carbon neutrality, and not 100% clean, renewable energy? Also, let's not lose sight of other emissions such as N₂O. Yes, dramatic cuts in CO₂ emissions do need to happen rapidly, and yes, this does require a complete transformation of industry, energy and transport. Nonetheless, N₂O emissions are also important and most N₂O emissions result from land use, such as food production and waste handling, which must also change.
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If emissions associated with pre- and post-production activities in the global food system are included, the emissions could be another 14% higher, i.e. as high as 37% of total net anthropogenic greenhouse gas emissions, the IPCC added.
In other words, all polluting emissions need to be reduced. Moreover, a recent paper by Jorgen Randers et al. points out that, even if all greenhouse gas emissions by people would stop immediately, and even if CO₂ levels in the atmosphere would revert back to pre-industrial levels, and even if with relatively modest rises in methane levels, overall temperatures would still keep rising for centuries to come. Another recent paper, by Tapio Schneider et al., points out that solar geoengineering may not prevent strong warming from direct effects of CO2 on stratocumulus cloud cover.
This means that the threat is even more menacing when including large methane releases that threaten to occur as temperatures keep rising in the Arctic and sediments at the seafloor of the Arctic Ocean threaten to get destabilized, resulting in the eruption of huge amounts of methane.
The image below illustrates that the joint impact of carbon dioxide and methane could cause the 1200 ppm CO₂e tipping point to be crossed in 2040. The image uses IPCC and WMO through 2019 to display three lines, with added trends:
A 1000-fold methane increase could occur, resulting in a rise of as much as 6°C within 80 years, with more to follow after that, according to a paper by Atsushi Obata et al.
The danger is illustrated by the images on the right (click on images to enlarge).
The first image shows that, on November 20 pm, 2020, the MetOp-1 satellite recorded high methane levels over the Arctic Ocean at 293 mb, which is at some 9 km altitude where the Stratosphere starts at the North Pole. The global mean methane level at that altitude was 1921 ppb.
Indeed, there is no time to lose. It is high time to stop the denial of the size of the threats and challenges that the world faces, the harm that could be inflicted and the speed at which developments could strike.
• Climate Plan
• When will we die?
• IPCC AR5 Workgroup 1
• WMO news release: Carbon dioxide levels continue at record levels, despite COVID-19 lockdown
• Understanding the Permafrost–Hydrate System and Associated Methane Releases in the East Siberian Arctic Shelf, by Natalia Shakhova, Igor Semiletov and Evgeny Chuvilin (2019)
• Damage of Land Biosphere due to Intense Warming by 1000-Fold Rapid Increase in Atmospheric Methane: Estimation with a Climate–Carbon Cycle Model - by Atsushi Obata et al. (2012)
• Possible climate transitions from breakup of stratocumulus decks under greenhouse warming, by Tapio Schneider et al. (2019)
• Solar geoengineering may not prevent strong warming from direct effects of CO2 on stratocumulus cloud cover - by Tapio Schneider et al.
• An earth system model shows self-sustained melting of permafrost even if all man-made GHG emissions stop in 2020 - by Jorgen Randers et al.
• Most Important Message Ever