NIUS:
Neue Studie: Deutsches Klima-Institut arbeitet für Angstmache mit „irreführenden, konstruiertem Szenario“
Eine Studie des Potsdam-Instituts für Klimafolgenforschung (PIK) sorgt derzeit für Aufsehen: „19 Prozent Einkommensverlust weltweit durch Klimawandel“. Der frühere Umweltsenator von Hamburg, Professor Fritz Vahrenholt, erklärt bei NIUS, wie die Studienautoren Angst schüren. Brisant: Sogar Wissenschaftler des Weltklimarats (IPCC) halten es für irreführend, mit dem in der Studie genutzten „Worst-Case-Szenario“ zu arbeiten.
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Aber gibt es wirklich Grund zu Beunruhigung und harten grünen Klimamaßnahmen, wie die Studie nahelegt? Professor Fritz Vahrenholt (SPD), früherer Umweltsenator von Hamburg, sagt gegenüber NIUS: „Die Studie arbeitet mit einem immer wieder genutzten, unsäglichen, aber ganz einfachen Trick. Sie nutzt eine extrem unrealistische Prognose aus den IPCC-Berichten, das Szenario 8.5, das auch unter IPCC-Wissenschaftlern nicht als Rechtfertigung für politische Entscheidungen akzeptiert wird.“
Weiterlesen auf NIUS
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The Sun and the Troposphere Control the Earth’s Temperature
The basis for this study is the flow of energy from the Troposphere to space and the role that water vapor and carbon dioxide (CO2) play in affecting the flow. Then, it analyzes the radiation profiles and compares them to the ratio of water molecules to CO2 molecules. Examining the radiation profiles of water vapor and CO2 showed the overlap made it virtually impossible to separate the warming effects. Calculating the ratio of water vapor molecules to CO2 molecules by proven physics and chemistry is accurate for separating the individual warming effects. The results of a quantitative examination show water vapor has 1,000 to 7,000 times more impact on the Earth’s temperature than CO2. The warming effect of CO2 versus concentration is linear. In contrast, the warming effect of water vapor versus concentration is curved. The lowest level of the atmosphere, the Troposphere, has most of the air mass and water vapor and exercises control over the Earth’s temperature. Energy leaving the Troposphere flows virtually unhindered to space. The Sun is Earth’s primary energy source, and its natural variations control its temperature.
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CERN:
CLOUD collaboration challenges current understanding of aerosol particle formation in polar and marine regions
Atmospheric aerosol particles exert a strong net cooling effect on the climate by making clouds brighter and more extensive, reflecting more sunlight back out to space. However, how aerosol particles form in the atmosphere remains poorly understood, especially in polar and marine regions.
Globally, the main vapor driving particle formation is thought to be sulfuric acid, stabilized by ammonia. However, since ammonia is frequently lacking in polar and marine regions, models generally underpredict aerosol particles in these regions.
A new study from the CLOUD collaboration now challenges this view, by showing that iodine oxoacids are acting synergistically with sulfuric acid to greatly enhance the particle formation rates.
The new findings, described in a paper published in the journal Science, build on earlier CLOUD studies that showed that iodine oxoacids rapidly form particles even in the complete absence of sulfuric acid. The results imply that climate models are substantially underestimating the formation rates of aerosol particles in marine and polar regions.
„Our results show that climate models need to include iodine oxoacids along with sulfuric acid and other vapors,“ says CLOUD spokesperson Jasper Kirkby. „This is particularly important in polar regions, which are highly sensitive to small changes in aerosol particles and clouds. Here, aerosol particles actually provide a warming effect by absorbing infrared radiation otherwise lost to space and re-radiating it back down to the surface.“
The CLOUD experiment is studying how aerosol particles form and grow from mixtures of vapors at atmospheric conditions in a large chamber. It differs from previous experiments both by maintaining ultra-low contaminants and by its precise control of all experimental parameters at conditions found in the real atmosphere. This includes the use of a CERN particle beam to simulate ions formed by galactic cosmic rays at any altitude in the troposphere.
The new CLOUD results show that iodine oxoacids greatly boost the formation rate of sulfuric acid particles. At iodine oxoacid concentrations that are typical of marine and polar regions—between 0.1 and 5 relative to those of sulfuric acid—the CLOUD measurements show that the formation rate of sulfuric acid particles is increased by 10- to 10 000-fold compared with previous estimates.
The CLOUD team found that this increase is due to two effects: first, iodous acid substitutes for ammonia to stabilize newly formed sulfuric acid particles against evaporation and, second, iodic acid facilitates the formation of charged sulfuric acid clusters. Using quantum chemistry, the collaboration has confirmed the synergy between iodine oxoacids and sulfuric acid, and calculated particle formation rates that closely agree with the CLOUD measurements.
„Global marine iodine emissions have tripled in the past 70 years due to thinning sea ice and rising ozone concentrations, and this trend is likely to continue,“ says Kirkby.
„The resultant increase of marine aerosol particles and clouds, suggested by our findings, will have created a positive feedback that accelerates the loss of sea ice in polar regions, while simultaneously introducing a cooling effect at lower latitudes. The next generation of climate models will need to take iodine vapors into account.“
Paper: Xu-Cheng He et al, Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere, Science (2023). DOI: 10.1126/science.adh2526
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The Ohio State University.
Tropical ice cores offer deeper insights into Earth’s temperature record
A new study suggests ice recovered from high tropical mountains can reveal key insights about Earth’s past climate changes.
Led by scientists at The Ohio State University, the study showed that oxygen-stable isotope records stored in tropical mountain glacier ice cores can be used to provide scientists with a distinct paleoclimate history of the planet’s middle and upper troposphere. By combining ice core proxy records, paleoclimate simulations and modern satellite measurements and comparing the results to those from previous climate models, they found that the temperature in this region of the atmosphere cooled by 7.35°C during the Earth’s glacial period, which for many researchers illuminates new theories about climate dynamics throughout the ages.
„Typically, you need hundreds of pieces of data to construct a record of global mean temperature,“ said Zhengyu Liu, lead author of the study and a professor of geography at The Ohio State University. „It turns out, in that region in the tropics and at that height, you can use just one, and it’s very consistent with many other independent constructions available, which rely primarily on sea surface temperature proxies.“
Because the ice core, collected from Nevado Huascarán in Peru, was formed in a high-mountain region disconnected from the oceans, samples recovered there are essentially unique „Goldilocks-type“ indicators of global mean temperature change.
Unlike ice recovered from opposite extremes of the planet such as Greenland or Antarctica, ice from tropical regions provides a happy medium, and holds evidence that is „just right“ for measuring Earth’s mean temperature throughout the ages. More importantly, said Liu, their findings show the first solely land-based estimate of global stage cooling, or how much Earth’s temperature decreased during its last glacial period.
The study, which was published recently in Science Advances, and presented in a poster session today (Dec. 14, 2023) at the annual meeting of the American Geophysical Union, found that surface temperatures during Earth’s glacial cooling stages diminished by as much as 5.9°C.
„This ice core is like a weather tower quietly recording atmospheric history,“ said Liu. According to the study, since the highest tropical ice records are not affected by regional features of the warming environment due to their unique elevation and location, the information these „weather towers“ collect is considered to be a more accurate measurement of surface global mean temperature as opposed to records that reflect regional changes.
It’s for this reason that information gained from even a single tropical ice core could likely be used to enhance scientists‘ understanding of a number of different climate elements, including temperature responses during periods of rapid climate change such as the one occurring today as well those likely to occur in the future, said Lonnie Thompson, co-author of the study and professor of Earth sciences and a senior research scientist at the Byrd Polar and Climate Research Center.
Potent greenhouse gases such as methane, large sources of which come from tropical wetlands, are also preserved in the bubbles in these very high-elevation ice cores where temperatures are very cold and no melting occurs. But by extracting the methane from the ice cores, scientists can construct a history of the changes in its atmospheric concentration. According to Thompson, as methane is a very potent greenhouse gas that can warm the atmosphere at alarming rates, it’s important to have a tropical archive of its past activity.
„Integrating these tropical records with those from the polar regions provides a more global picture,“ he said. „Thus, acquiring these high-elevation tropical climate histories is very important as their data will greatly advance our understanding of Earth’s climate on this planet.“
The study’s conclusions also shed light on a decades-old scientific debate on how oxygen-stable isotopes in tropical ice cores can be used to interpret climate variations over time. Previous studies have debated whether tropical ice core samples serve as proxies for determining atmospheric changes through either temperature or precipitation processes. This study suggests the tropical ice cores serve as a recorder of air temperature in the mid-upper troposphere across tropics, and more interestingly, as a recorder of global mean surface temperature during Earth’s last glacial period.
Altogether, the study aims to improve researchers‘ understanding of paleoclimatology, as a better understanding of Earth’s climate patterns could help refine both future climate models and extreme weather predictions.
Yuntao Bao, another co-author of the study and a Ph.D. student in geography at Ohio State, said that their research wouldn’t have been possible without the input of colleagues across many other fields, not just those in the scientific community interested in studying ice cores.
„The answer to your questions will not come to you the first time, but collaborating with others who have different backgrounds than our own improves our understanding of the world,“ said Bao. „With more perspectives, our future work can reach further than it’s ever gone.“
Paper: Zhengyu Liu et al, Tropical mountain ice core δ 18 O: A Goldilocks indicator for global temperature change, Science Advances (2023). DOI: 10.1126/sciadv.adi6725