Three events may cause intense global warming in 2023-24. These are El Nino, solar irradiance and the Tonga volcanic eruption. We will probably pass 1.5 degrees of global warming in the late summer of this year.
Global temperatures are heavily affected by changes in the eastern Pacific Ocean. When this area cools there is a global, “La Nina”, cooling event and when it warms there is a global, “El Nino” warming event. The graph below shows the way that El Nino generally raises global temperature about 0.2 to 0.5 degrees from when it begins to its peak:
We are currently leaving the long La Nina phase and entering an El Nino which is due to be fully active in late summer/autumn 2023 and will last into 2024. Ocean surface temperatures are already at record levels and the El Nino has only just begun. This is likely to add at least 0.3 degrees to global temperatures.
The sun has an eleven year cycle in activity which varies the amount of energy that it transmits to earth. The peak of the latest cycle will happen in 2024 but levels of irradiance are already at a 20 year maximum. The coming maximum will add 0.1 degrees to global warming.
The 2022 Hunga Tonga-Hunga Ha’apai, undersea, volcanic eruption near Tonga was one of the largest in the past century. It was unusual because it blasted 146m tonnes of water into the stratosphere. This water vapour has a warming effect and is likely to add 0.05 to 0.1 degrees to global warming. (See Tonga volcano eruption raises ‘imminent’ risk of temporary 1.5C breach ).
The overall effect of these three factors is about 0.5 degrees. According to Berkeley Earth, a leading centre of climate research, global temperature rise from pre-industrial is likely to be about 1.25 degrees without the triple whammy. Add the triple whammy and we could see 1.75 degrees (plus/minus 0.17 degrees) in late summer 2023 to end of 2024.
This will provide fuel for climate protests but it may also kill a lot of people if it is associated with droughts and heat waves.
As an afterthought, there is a growing disconnect between atmospheric CO2 levels and reported emissions of CO2. The atmospheric CO2 is rising relentlessly even though reported emissions are supposed to have stabilised.
25/4/2023