(the following is an excerpt from the blogpost
Methane keeps rising, from October 5, 2022, by Sam Carana on the Arctic News blog:)
"How high could the temperature rise be by 2026?
There are further scenarios that could cause the clouds tipping point to be crossed soon, e.g. if the rise in methane kept following a trend as depicted in the image below.
Even without such an increase in methane, a huge temperature rise could eventuate by 2026, first of all due to a cataclysmic alignment of El Niño and sunspots.
We are currently in the depths of a persistent La Niña, as illustrated by the image on the right, adapted from
NOAA and this suppresses the temperature rise at the moment.
The next El Niño is already overdue, so the peak of the next El Niño may well coincide with a peak in sunspots which look set to reach a higher than expected maximum impact around July 2025. The rise in sunspots from May 2020 to July 2025 could make a difference of some 0.15°C, concluded an
earlier post.
Moving from the bottom of the current La Niña to the peak of a strong El Niño could make a difference of more than half a degree Celsius, so the rise due to the combined impact of El Niño and sunspots could be 0.65°C by 2025.
When adding this to the temperature rise that has already occurred and that, when measured from
pre-industrial could be as high as 2.29°C, the total rise could be 2.94°C by 2025.
Such a huge rise could cause heatwaves and droughts that could result in a huge peak in power demand, as everyone switches on their air conditioners, while at the same time rivers could either dry up or their water could become too hot to cool powerplants. This could bring the grid down, which would mean that coal-fired power plants would stop emitting sulfates.
If the grid is down, heaters won't work that need power for their thermostat. Electric pumps won't work, so there may no longer be water coming out of taps. The internet won't work where routers require power from the grid.
Furthermore, the heat could cause asphalt and tarmac to melt and rail tracks to buckle, while airports could be closed, not only because the surface of the runway could get too hot, but also because the air could become too thin for planes to take off due to the heat.
In short, traffic, transport and industrial activities such as smelting, which are emitting a lot of sulfates as well at the moment, could grind to a halt at many places on the Northern Hemisphere.
The result would be a large decrease of the sulfate aerosols that are currently masking the full wrath of global warming.
How much difference could it make? The IPCC in AR6 estimates the aerosol ERF to be −1.3 W m⁻², adding that there has been an increase in the estimated magnitude of the total aerosol ERF relative to AR5. In AR6, the IPCC estimate for liquid water path (LWP, i.e., the vertically integrated cloud water) adjustment is 0.2 W m⁻², but a
recent analysis found a forcing from LWP adjustment of −0.76 W m⁻², which would mean that the IPCC estimate of −1.3 W m⁻² should be changed to -2.26 W m⁻². When using a sensitivity of ¾°C per W m⁻², this translates into an impact of -1.695°C. Since the IPCC's total for aerosols includes a net positive impact for warming aerosols such as black carbon, the impact of cooling aerosols only (without warming aerosols) will be even more negative.
This supports the 2016 analysis that warned that by 2026 there could be a 1.9°C temperature rise due to a decrease in cooling aerosols, while there could be an additional 0.6°C temperature rise due to an increase in warming aerosols and gases as a result of more biomass and waste burning and forest fires by 2026.
So, together with the upcoming El Niño and a peak in sunspots, that could result in a total rise by 2026 of 5.44°C above pre-industrial. There's more to come! Additionally, the 2016 analysis warned about further rises in temperature due to loss of Arctic sea ice and permafrost, and associated changes, as well as further rises due to gases, concluding that there could be a temperature rise by 2026 of more than 10°C compared to pre-industrial.
With a temperature rise of more than 10°C by 2026, the clouds tipping point will also be crossed, which would result in a total rise of more than 18°C by 2026.
Keep in mind that humans are likely to go extinct with a rise of 3°C, as illustrated by the image below, from an analysis discussed in an earlier post."
My comment: This is a worst-case scenario, I prefer to believe in a middle way between Sam Carana (the extreme pessimist) and the official UN story of a 3 degrees Celsius rise by 2100, I believe temperatures will be at 3 degrees Celsius above preindustrial around 2030, when civilization will collapse, and that the last human will go extinct about 2040. This presupposes that the Arctic Methane Time Bomb will not be fired during that time. If it will, it may be game over already 2026. Note that Sam Carana does not take into consideration the full wrath of the methane bomb in his calculations above, he presupposes a smooth rise of methane in the atmosphere, only 1,1 degrees Celsius rise because of methane, not the 10 degrees Celsius rise (because of a 50 gigaton burp of methane) proposed by Malcolm Light and the even greater temperature rise that a 700 gigaton burp (proposed by Peter Wadhams) would lead to (that might be Venus for planet earth).
