Science Snippets: Earth's Temperature Could Increase by 14 C

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Yes, you read that correctly: Earth’s temperature could increase by 14 C, otherwise expressed as 25 degrees Fahrenheit. The headline from 27 August 2024 at SciTechDaily reads Earth’s Temperature Could Increase by 25 Degrees: Startling New Research Reveals That CO2 Has More Impact Than Previously Thought. The article opens with a figure that is titled “A study reveals that doubling atmospheric CO2 could raise Earth’s average temperature by up to 14 degrees, far exceeding current UN estimates. The research, based on a 45-year-old Pacific Ocean drill core, highlights a stronger relationship between CO2 levels and temperature than previously understood.” Here’s the subhead: “Analysis of Pacific Ocean sediments shows doubling of atmospheric CO2 might raise Earth’s temperature by up to 14 degrees, exceeding IPCC predictions, with historical data indicating significant future climate impacts.”

Of course, there is no guarantee that humans will be present to observe a 14 C temperature increase. Indeed, I cannot imagine we will survive the rapid rate of environmental change associated with a 4 C rise in temperature during the next several years.

The lead author of the associated peer-reviewed paper is then quoted in the SciTechDaily article: “The temperature rise we found is much larger than the 2.3 to 4.5 degrees Celsius that the UN climate panel, IPCC, has been estimating so far.” This, of course, is not surprising. The IPCC was designed to fail when it was created during the Ronald Reagan administration. It replaced the Advisory Group on Greenhouse Gases, an organization with much more realistic analyses about the future we face.

According to the article in SciTechDaily, the researchers used a 45-year-old drill core extracted from the Pacific Ocean. In the location from which the core was extracted, the ocean floor had been characterized by oxygen-free conditions for many millions of years. As a result, according a Professor working with the Royal Netherlands Institute for Sea Research, carbon is preserved because organic matter is broken down very slowly by microbes.

The researchers in this study developed a new approach to determine past atmospheric CO₂ content. Specifically, they used the chemical composition of two substances found in algae: chlorophyll and cholesterol. Algae absorbs CO₂ from the water and fixes the CO₂ via photosynthesis. Whereas algae prefer the customary isotope of carbon, ¹²C, the algae will fix the rarer ¹³C, especially at the lower CO₂ concentration found at great depth in the ocean. The ¹³C content is therefore a measure of the CO₂ content of the ocean water. That, in turn, correlates with the CO₂ content of the atmosphere. Using this new method and the subsequent analyses indicates that the CO₂ concentration dropped from about 650 parts per million 15 million years ago to the 280 parts per million with which we are familiar as the Industrial Revolution began in about 1750. When the researchers in this study plotted the temperatures and atmospheric CO₂ levels during the last 15 million years, they found a strong relationship. The average temperature 15 million years ago exceeded 18 C, about 4 C warmer than today. This is also about the temperature the Intergovernmental Panel on Climate Change predicts for 2100 in their most extreme scenario.

Perhaps you see the problem here. As stated by the Professor working with the Royal Netherlands Institute for Sea Research, “CO₂ over the past 15 million years has never before been examined from a single location.” The upper thousand meters of this newly analyzed core corresponds to the last 18 million years. From this stunningly deep core, researchers were able to determine ancient CO₂ levels and the associated global temperature.

I turn now to the open-access, peer-reviewed paper in Nature Communications. Published 18 June 2024 and written by six scholars, the article is titled Continuous sterane and phytane δ¹³C record reveals a substantial pCO₂ decline since the mid-Miocene. The title is a bit obtuse for most of us, so I will turn to information from the Abstract for a more coherent description: “Constraining the relationship between temperature and atmospheric concentrations of carbon dioxide (pCO₂) is essential to model near-future climate. Here, we reconstruct atmospheric concentrations of carbon dioxide values over the past 15 million years, providing a series of analogues for possible near-future temperatures and atmospheric concentrations of carbon dioxide, from a single continuous site (DSDP Site 467, California coast). We reconstruct atmospheric concentrations of carbon dioxide values using sterane and phytane, compounds that many phytoplankton produce and then become fossilised in sediment. From 15 million to 300,000 years ago, our reconstructed atmospheric concentrations of carbon dioxide values steadily decline from 650 ± 150 to 280 ± 75 ppm volume, mirroring global temperature decline. Using our new range of pCO₂ values, we calculate average Earth system sensitivity and equilibrium climate sensitivity, resulting in 13.9 °C and 7.2 °C per doubling of atmospheric concentration of carbon dioxide, respectively. These values are significantly higher than IPCC global warming estimations, consistent or higher than some recent state-of-the-art climate models, and consistent with other proxy-based estimates.”

This comes as no surprise for anybody paying attention to the IPCC global warming estimations. The 14 C increase in global average temperature described in this peer-reviewed paper brings to mind relatively honest assessments produced by the Advisory Group on Greenhouse Gases before it was replaced by the IPCC during the Ronald Reagan administration. For example, the predecessor to the IPCC concluded that 1 C above the 1750 baseline would trigger self-reinforcing feedback loops. Many such feedback loops have occurred and are affecting life on Earth. The Advisory Group on Greenhouse Gases warned of the relationship between societal breakdown and extinction of non-human species. This relationship is clearly on display.

The most surprising outcome of the papers in SciTechDaily and Nature Communications is the honesty expressed by paid climate scientists. Although I question the delayed timing of Earth reaching 14 C above the 1750 baseline, not to mention the survival of life on Earth between now and then, it’s good to see mention of numbers that reflect ongoing events and our likely future. Although it’s good to see mention of such numbers, and it’s also horrifying. Reality can be like that, which brings to mind a couple of quotes from Marcus Aurelius.

I have mentioned one of the lines from Aurelius previously in this space: “It is not death that a man should fear, but he should fear never beginning to live.” The second quote reminds us to live in the current moment: “Be content with what you are, and wish not change; nor dread your last day, nor long for it.”

These thoughtful lines from Aurelius provide context for ideas such as a 14 C rise in global-average temperature within the next several decades. Most importantly, they remind us that what matters in our short lives is living in the here and now without fear. Regardless how many times I have mentioned these ideas, I doubt it’s enough.