Study: Reduced sulphur content in shipping fuel caused ‘nearly 80%’ of recent atmospheric warming

Posted: May 30, 2024 by oldbrew in atmosphere, climate, Clouds, Emissions, geo-engineering, modelling, pollution, research
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Due to a 2020 shipping regulation…’The net planetary heat uptake has increased by 0.25 Wm−2 since 2020, making the 0.2 Wm−2 due to IMO2020 nearly 80% of the total increase.’ The study also says: ‘The 2023 record warmth is within the ranges of our expected trajectory. The magnitude of IMO2020 induced warming means that the observed strong warming in 2023 will be a new norm in the 2020 s.’ — Two general comments to make here: (1) cloud physics is admitted to be not well understood, and (2) could night-time clear(er) skies mean (more) cooling, in theory at least?
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An 80% reduction in sulphur dioxide shipping emissions observed in early 2020 could be associated with substantial atmospheric warming over some ocean regions, according to a modelling study published in Communications Earth & Environment.

The sudden decline in emissions was a result of the introduction of the International Maritime Organization’s 2020 regulation (IMO 2020), which reduced the maximum sulphur content allowed in shipping fuel from 3.5% to 0.5% to help reduce air pollution, says EurekAlert.

Fuel oil used for large ships has a significantly higher percentage content of sulphur than fuels used in other vehicles. Burning this fuel produces sulphur dioxide, which reacts with water vapour in the atmosphere to produce sulphate aerosols.

These aerosols cool the Earth’s surface in two ways: by directly reflecting sunlight back to space [Talkshop comment – daytime effect only]; and by affecting cloud cover.

Increasing the number of aerosols increases the number of water droplets that form whilst reducing their size, both increasing the cloud coverage and forming brighter clouds which reflect more sunlight back to space.

Marine cloud brightening is a form of geoengineering where marine clouds are deliberately seeded with aerosols to achieve this effect.

Tianle Yuan and colleagues calculated the effect of IMO 2020 on the atmospheric levels of sulphate aerosols over the ocean and how this affected cloud composition. They found substantial reductions in both the levels of atmospheric aerosols and the cloud droplet number density.

The greatest modelled aerosol reductions were in the North Atlantic, the Caribbean Sea, and the South China Sea — the regions with the busiest shipping lanes.

The authors then estimated the effect of IMO 2020 on Earth’s energy budget (the difference between the energy received from the Sun and the energy radiated from the Earth) since 2020. They calculated that the estimated effect is equivalent to 80% of the observed increase in the heat energy retained on Earth over that period.

Full article here.

Comments
  1. Peter Norman says:

    OB, at some stage we have to call out some of this so called research as bow-locks? Just saying.

  2. The history of climate science, actually, “so called climate science”, find even one factor that correlates with temperature change and give credit to any change in temperature to that one factor, even though that factor did not correlate with temperature change over the past hundreds, thousands or millions of years, even when the temperatures in the northern and southern hemisphere did not correlate even due to that factor, they should have correlated. Correlation is not causation but lack of correlation is evidence of real falsification and/or error.

  3. Phoenix44 says:

    It relies entirely on CO2 driving warmer temperatures. So it’s modelled on a flawed assumption.

  4. oldbrew says:

    Does a 2020 shipping regulation change explain 80% of a temperature rise that mainly occurred in 2023? Or…

    V. important new paper re climate impacts of the Hunga Tonga eruption

    https://x.com/curryja/status/1796217947272442230

    Paper: Further research is needed to fully understand the multi-year effects of SWV anomalies and their relationship with climate phenomena like El Nino Southern Oscillation.

    © 2024 American Meteorological Society. 

  5. David Paterson says:

    They just cannot accept the fact that this absolves CO2. The gradual warming of the oceans caused by a reduction in cloud cover over tropical oceans over several decades was simply exacerbated by suddenly switching off these mobile cloud seeding units.

    hopefully a good step towards the beginning of the end of the hoax.

  6. oldbrew says:

    Solar flares in 2023 exceeded anything in the last two solar cycles (not checked earlier SCs). Looks like 2024 is on track to match or beat 2023, barring a slowdown.

    https://www.spaceweatherlive.com/en/solar-activity/solar-cycle.html

    Or we can talk about shipping regulations 🤔

  7. Jaime Jessop says:

    It’s absurd. Look at their graph of the expected warming due to IMO2020. It completely fails to reflect actual global temperature variations from that point onwards. First, global temperature dips sharply (presumably due to La Nina), then it rises very rapidly and suddenly beginning early 2023. The basis of their claim that it was IMO2020 wot dunnit is that the “2023 record warmth is within the ranges of our expected trajectory”! So they found ONE datapoint that fits their computer modelled theory and so pronounced their theory to be ‘fact’!

  8. oldbrew says:

    The objective could be to gloss over NASA/GISS climate alarmist Gavin Schmidt’s recent paper saying ‘we don’t know what’s going on any more’.

    2023’s record heat partly driven by ‘mystery’ process: NASA scientist

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