Tonga Eruption

[SteamyTea]

More water than sulphur for a change.

 

Environment

2022 Tonga eruption means we may hit 1.5°C of global warming earlier

The massive eruption of a Tongan volcano in January 2022 has made it more likely that we will exceed 1.5°C of global warming within the next five years, but the effect will disappear by 2035

12 January 2023

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By Kate Ravilious

 

A cloud of ash erupting from the Hunga Tonga-Hunga Ha’apai volcano on 15 January 2022, photographed by a satellite

NOAA/Alamy Stock Photo

The chances of temporarily exceeding 1.5°C of global warming within the next five years have increased markedly due to the spectacular eruption of an underwater volcano in Tonga in January 2022.

The explosive Hunga Tonga-Hunga Ha’apai event was the most powerful of the 21^st century so far. Large eruptions are usually dominated by sulphur dioxide emissions, which cause climate cooling, but the Tonga one was very unusual because it released a lot of water vapour – a powerful greenhouse gas. Satellite measurements indicate that it increased the water vapour content of the stratosphere by 10 to 15 per cent. This is expected to cause temporary global warming.

Stuart Jenkins at the University of Oxford and his colleagues estimated how the extra water vapour would change the balance of incoming and outgoing energy in the atmosphere. They then simulated the resulting temperature anomaly until 2035 under two scenarios: one in which carbon emissions continue on their current trajectory and one with ambitious climate mitigation policies.

They found that on the current emissions trajectory, the Tonga eruption will produce a small and short-lived warming effect, increasing the chance from 50 to 57 per cent of at least one of the next five years reaching 1.5°C above pre-industrial levels for the first time.

In the ambitious climate mitigation scenario, the chances of one of the next five years exceeding 1.5°C rises from 60  to 67 per cent. That’s because aerosol particles from human air pollution reflect radiation and currently help to slow the pace of warming, but ambitious mitigation policies cut emissions of all pollutants quickly, resulting in faster rates of warming in the short term.

 

Read more:

The first breach of 1.5°C will be a temporary but devastating failure

 

The 2015 Paris Agreement set a goal of limiting global warming to 1.5°C above pre-industrial levels. Exceeding this in a coming year wouldn’t mean we have failed to meet this objective, Jenkins points out. “Whilst Tonga may increase our chances of seeing a 1.5°C year in the near term, it is a natural influence on the climate system and doesn’t contribute to our measures of success or failure in the Paris Agreement,” he says.

The research also shows that the Tonga effect will have disappeared by 2035.

“This is a timely study and demonstrates that we can relatively quickly estimate the impact that a volcanic eruption will have on surface temperature,” says Anja Schmidt at the Ludwig Maximilian University of Munich, Germany. “Even though most volcanic eruptions cool the Earth’s surface, this study demonstrates that only rapid and rigorous reductions in anthropogenic emissions will substantially decrease the risk of exceeding very dangerous levels of warming. We can’t rely on the short-term cooling effect of most volcanoes to save us from the impacts global warming will have.”

Journal reference: Nature Climate Change, DOI: 10.1038/s41558-022-01568-2

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[ProDave]

So can we STOP calling it MAN MADE global warming.  It wasn't us wot did it.

[SteamyTea]

2 minutes ago, ProDave said:

So can we STOP calling it MAN MADE global warming.  It wasn't us wot did it.

Some will.

They are the ones that still think GW is just weather.