Great Spangled Fritillary (Speyeria cybele)
Ice Age National Scientific Reserve Unit, Wisconsin, USA
2017-06-19 049AAA
Sam Carana
TEMPERATURE RISE
On top of the February 28, 2023 daily average of 422.88 ppm for carbon dioxide, methane can add 384.71 ppm CO₂e when using a 1-year GWP of 200 for the 1923.57 ppb November 2022 methane mean by NOAA.
While methane at higher altitude can reach even higher levels than NOAA's marine surface data, using NOAA's November 2022 mean would leave just 392.41 ppm CO₂e for further forcing before the Clouds Tipping Point would get crossed, as the image illustrates.
Further forcing comes from nitrous oxide and other greenhouse gases, while rises in other gases and further changes such as caused by sea ice loss and changes in aerosols can also speed up the temperature rise.
The upcoming temperature rise on land on the Northern Hemisphere could be so strong that much traffic, transport and industrial activity will grind to a halt, resulting in a reduction in cooling aerosols that are now masking the full wrath of global heating. These are mainly sulfates, but burning of fossil fuel and biomass also emits iron that helps photosynthesis of phytoplankton in oceans, as a 2022 study points out.
Without these emissions, the temperature is projected to rise strongly, while there could be an additional temperature rise due to an increase in warming aerosols and gases as a result of more biomass and waste burning and forest fires.
The temperature could also be pushed up further due to reductions in the carbon sink on land. An earlier post mentions a study that found that the Amazon rainforest is no longer a sink, but has become a source, contributing to warming the planet instead; another study found that soil bacteria release CO₂ that was previously thought to remain trapped by iron; another study found that forest soil carbon does not increase with higher CO₂ levels; another study found that forests' long-term capacity to store carbon is dropping in regions with extreme annual fires; another earlier post discussed the Terrestrial Biosphere Temperature Tipping Point, coined in a study finding that at higher temperatures, respiration rates continue to rise in contrast to sharply declining rates of photosynthesis, which under business-as-usual emissions would nearly halve the land sink strength by as early as 2040.
This earlier post also discusses how CO₂ and heat taken up by oceans can be reduced. A 2021 study on oceans finds that, with increased stratification, heat from climate warming less effectively penetrates into the deep ocean, which contributes to further surface warming, while it also reduces the capability of the ocean to store carbon, exacerbating global surface warming. A 2022 study finds that ocean uptake of CO₂ from the atmosphere decreases as the Meridional Overturning Circulation slows down. An earlier analysis warns about growth of a layer of fresh water at the surface of the North Atlantic resulting in more ocean heat reaching the Arctic Ocean and the atmosphere over the Arctic, while a 2023 study finds that growth of a layer of fresh water decreases its alkalinity and thus its ability to take up CO₂, a feedback referred to as the Ocean Surface Tipping Point.
While loss of Arctic sea ice and loss of Permafrost in Siberia and North America are often regarded as tipping points, Antarctic sea ice loss, and loss of the snow and ice cover on Greenland, on Antarctica and on mountaintops such as the Tibetan Plateau could also be seen as tipping points. Another five tipping points are:
- The Latent Heat Tipping Point
- The Seafloor Methane Tipping Point
- The Clouds Tipping Point
- The Terrestrial Biosphere Temperature Tipping Point
- The Ocean Surface Tipping Point
Altogether, the rise from pre-industrial to 2026 could be more than 18.44°C, while humans are likely to go extinct with a rise of 3°C.
From the post 'Dire situation gets even more dire', at:
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