Ship Tracks captured in September 2009 by NASA imagery. These tracks are caused when sulfate emissions from burning fossil fuels create cloud condensation nuclei
that result in the ship tracks seen in this image. These clouds are common and result in extra sunlight being reflected back into space, cooling Earth.
No need to ruminate for 20 years about 1.5°C. It’s coming in 2024. (Hansen – with commentary)
El Nino Fizzles. Planet Earth Sizzles. Why?
First Published October 13, 2023 by James Hansen and associates at Hansen’s Columbia University page
(Update: Of the several temperature datasets globally, all but Berkely were right at 1.5 C, with Berkely Earth at 1.54 C. The reason and the reason Berkeley Earth is the most accurate is that they us far more polar and ocean data than the others.)
Hansen’s latest communication, suggests it is plausible that 2023 will be the last year we see below a global average temperature below 1.5 C warming above pre-industrial times, not the early 2030s as is commonly understood from understated climate findings and the statements of the Intergovernmental Panel on Climate Change (IPCC).
Summary: Because of unmasking of sulfates with new Chinese air regs and new low sulfur fuel shipping regs, plus the early stages of a moderate Nino, it is appearing quite plausible we will hit 1.6 to 1.7 C warming above the late 19th century in 2024, for the 12-month average, not a monthly. With a 0.2 C to 0.3 C rebound cooling after the El Nino dissipates, this means it is plausible we will not fall below 1.5 C again.
Hansen emphasizes this quite plausible reality that we will pass the 1.5 C annual average temperature threshold in 2024 with, “There will be no need to ruminate for 20 years about whether the 1.5°C level has been reached, as IPCC proposes. On the contrary, Earth’s enormous energy imbalance assures that global temperature will be rising still higher for the foreseeable future.”
Few in science communications are acknowledging the importance of this “unmasking” of warming because of new air pollution regulations in China and shipping. These new regs are intended to reduce air pollution from burning fossil fuels that are responsible for millions of deaths globally every year from respiratory distress. Natural sulfates in air pollution emissions from fossil fuels cool Earth, not warm it like global warming gasses and mechanisms. These sulfates are called bright aerosols and they reflect sunlight back into space before it can cause warming and be trapped by the greenhouse effect.
IPCC reports that these aerosols are responsible for about 0.5 C cooling, literally masking the same amount of warming (1). When this cooling sulfate pollution is limited by air pollution regulations, the masked warming is unmasked.
El Nino warming is responsible for a bit of the increase in the warming rate but traditionally, El Nino’s warming effects lag by a half or year or thereabouts, where El Nino’s effects mostly do not manifest until the winter following the increase in Central Pacific Ocean temperatures that signify an El Nino. In addition, the end of effects of both El Nino and La Nina, where La Nina is the opposite of El Nino with Central Pacific temperatures surface ocean temperatures cooler than normal, hang over for up to six months before returning to normal. The triple dip and uncommonly large La Nina that ended this last winter and spring was supposed to have created a summer with a cooling influence from La Nina’s hangover, instead of the we endured “gobsmackingly bananas” temperatures that Hansen believes were largely caused by reduction of sulfate air pollution in China and shipping.
Hansen suggests that not only has the warming rate increased as we proceed further into climate change, and not only has El Nino contributed to additional warming, but the unmasking of aerosol cooling has very likely played a large role in the jump in global temperatures we have seen in 2023. This unmasking has only just begun and will proceed as the new air pollution regulations are fully implemented.
Another important note: The comment above, “will not fall below 1.5 C” means that we will not see a global annual average temperature below 1.5 C again, until we restore our climate of course, which our current further warming to a minimum of 1.5 C climate policy will not do. To restore our climate, we have to remove CO2 that has accumulated in our sky because of historic emissions, and we have to do it faster than the further warming to 1.5 C scenarios suggestion of by 2100.
This new climate restoration policy of returning our global temperature to less than 1 degrees C, or back to within the evolutionary boundaries of our Earth systems, will restore the repeatedly unprecedented extremes we are seeing back return to their normal rare levels, eliminate climate change inequity and injustice, and stabilize our currently collapsing Earth systems.
References:
IPCC 2013 Summary for Policy Makers (SPM), page 11, C. Drivers of Climate Change, bullet 7. Up to (-)1.9 to (-) 0.1Wm(-2) of warming has been masked by aerosols out of 2.29 Wm(-2) (Bullet 1) of total warming experienced to date. This equals 57 percent of total warming masked by aerosols and does represent the high end of the range.