Science Snippets: AME Update

Draft script:

From Phys.Org comes this headline on 8 April 2024: Study presents evidence that recent reductions in aerosol emissions create an additional warming effect. I’ll read the opening paragraph: “Recent reductions in emissions of tiny particles, the major cause of air pollution globally, have led to more heat in the Earth’s climate system. This is shown in a new international study led by the Centre for International Climate and Environmental Research and published in Communications Earth & Environment. I’ll have more information from the peer-reviewed, open-access paper in Communications Earth & Environment shortly.

The paper in Phys.Org provides a good overview of the aerosol masking effect in paragraphs two and three: “Satellite measurements clearly show that more heat is entering the Earth's atmosphere from the sun compared to the amount of terrestrial energy escaping to space. This so-called Earth energy imbalance leads to accumulation of heat and warming of the Earth's surface.

It is well known that man-made emissions of CO₂ and other greenhouse gases have been the major cause of global warming in recent decades, and that emissions of particles have masked part of this warming. Most of the particles, especially sulfate, reflect sunlight and therefore act to cool the planet. In the last couple of decades, however, this cooling effect has reversed and now contributes to a warming due to extensive measures to improve air quality in many regions worldwide.”

As I have mentioned several times in this space, our collective efforts to clean up the mess to which we have collectively contributed have produced the opposite of the intended effect. The paper in Phys.Org refers to a figure: “The authors found that the recent reductions in man-made particle emissions needed to be accounted for in order for the models to reasonably match the satellite measurements (see figure above; black vs. orange line). When the authors assumed that the particle emissions did not change over the time period (green line), the simulated heating of the Earth was considerably reduced.”

Taking a close look at the figure, we see that the straight black line eclipsed the straight orange line in 2010. There is a lot of variation, as illustrated by the 2001-2023 annual anomalies from satellite observations. However, the explanation on the right side of the figure clearly indicates that the trend caused by changes in man-made particle emissions is substantial, at 0.2 Watts per meter squared per decade. This is about 60% of the trend caused by changes in greenhouse gases. This is very significant, especially considering how seldom the corporate media, government officials, and paid climate scientists mention the importance of aerosol masking.

This story was reported by Wired on 15 April 2024 under the headline The Paradox That’s Supercharging Climate Change. The subhead is well-selected: “Humanity needs to burn less fossil fuels. But that means fewer aerosols to help cool the planet—and a potential acceleration of global warming.” I take issue with the word potential in the subhead. The picture is clear: The aerosol masking effect has been reported in the peer-reviewed literature since 1929, as I have reported previously in this space. Loss of aerosols will rapidly heat our already overheated planet, as indicated by dozens of peer-reviewed papers.

The article in Wired opens with this paragraph: “No good deed goes unpunished—and that includes trying to slow climate change. By cutting greenhouse gas emissions, humanity will spew out fewer planet-cooling aerosols—small particles of pollution that act like tiny umbrellas to bounce some of the sun’s energy back into space.”

The second paragraph in the Wired article quotes a climate researcher at the Center for International Climate Research in Oslo, Norway: “Even more important than this direct reflection effect, they alter the properties of clouds. In essence, they make the clouds brighter, and the clouds reflect sunlight back into space.”

This all sounds good, when context is not provided. After all, reflecting sunlight back into space so that it cannot contribute to additional overheating of the planet sounds like a wonderful idea. However, context matters.

A few paragraphs into the article in Wired, we find a reference to the ongoing, rapid heating of Earth: “ocean temperatures … have soared to and maintained record highs for over a year, stunning scientists. The senior scientist at the Woodwell Climate Research Center is quoted: “The preponderance of those records and the margins by which they were broken was eye-opening. Until society manages to stop increasing the greenhouse blanket, record-smashing events like those of 2023 will become more common, even without the boost from El Niño.”

The peer-reviewed, open-access paper was published in Communications Earth & Environment on 3 April 2024. Titled Recent reductions in aerosol emissions have increased Earth’s energy imbalance, the paper was written by 12 scholars. The Abstract includes this information: “We find that the effective radiative forcing due to anthropogenic aerosol emission reductions has led to a 0.2 ± 0.1 W m⁻² decade⁻¹ strengthening of the 2001–2019 imbalance trend. The multi-model ensemble reproduces the observed imbalance trend of 0.47 ± 0.17 W m⁻² decade⁻¹ but with 10-40% underestimation. With most future scenarios showing further rapid reductions of aerosol emissions due to air quality legislation, such emission reductions may continue to strengthen Earth’s energy imbalance, on top of the greenhouse gas contribution. Consequently, we may expect an accelerated surface temperature warming in this decade.”

I take issue with that final sentence: “[W]e may expect an accelerated surface temperature warming in this decade.” Abundant evidence indicates the aforementioned acceleration has already begun. As reported by the designed-to-fail Intergovernmental Panel on Climate Change, Earth is in the midst of the most abrupt change in the environment in planetary history. Here’s the quote I often use from Global Warming of 1.5 Degrees, published on 8 October 2018: “… even abrupt geophysical events do not approach rates of human-driven change.” In other words, we have a scientifically conservative source pointing out that the ongoing acceleration of Earth’s temperature is unprecedented. The ongoing acceleration of Earth’s temperature is unprecedented. It’s exponential. It’s off-the-charts. How many ways can I say we are in uncharted waters? How many ways can I say these uncharted waters are cause for concern of the worst possible kind … the extinction kind?