Jean-Pascal Van Ypersele

OA - Liste

filtre:
Columbia

2026

240 000. C’est le nombre de particules de plastique qu’une équipe de l’université Columbia a dénombré dans un seul litre d’eau en bouteille. Publiée en janvier 2024 dans la revue scientifique PNAS, l’étude révèle des quantités jusqu’ici insoupçonnées de minuscules particules de plastique dans l’eau embouteillée. Un chiffre qui renverse une conviction profondément ancrée : celle que la bouteille, c’est la garantie de boire propre.
We infer that 2026 is likely to be the warmest year in the period of instrumental data, based on a physics-based approach with identifiable assumptions. This approach may help us learn something in 2026 about the mechanisms of climate change. The figures in this post and our other current papers will be continually updated on our website,2 when they remain relevant. We are also now on Substack3.
Dr. Hansen periodically posts commentary on his recent papers and presentations and on other topics of interest to an e-mail list. To receive announcements of new postings, please click here.
The European Center for Medium Range Weather Forecasts (ECMWF) earlier this year issued a forecast of a strong (“Super”) El Nino to begin later this year and peak in early 2027, as we have discussed in two earlier posts.3,4 El Ninos are important because of the large effects that they have on global weather, even though those effects are not always consistent from one El Nino to another. El Ninos have even greater effect in combination with ongoing global warming, e.g., Radfar et al.5 find that the combination of an El Nino with increasingly prevalent marine heat waves results in tropical cyclones consistently producing higher maximum wind speeds, storm surges, and precipitation rates, and Liu et al.6 describe evidence of El Ninos strengthened control over global climate anomalies in a warmer world
The world seems headed into another El Nino, just 3 years after the last one. Such quick return normally would imply, at most, an El Nino of moderate strength, but we suggest that even a moderately strong El Nino may yield record global temperature already in 2026 and still greater temperature in 2027. The extreme warming will be a result mainly of high climate sensitivity and a recent increase of the net global climate forcing, not the result of an exceptional El Nino, per se. We find that the principal drive for global warming acceleration began in about 2015, which implies that 2°C global warming is likely to be reached in the 2030s, not at midcentury.
l'observatoire US de la dérégulation environnementale

2025

Climate sensitivity is substantially higher than IPCC’s best estimate (3°C for doubled CO2), a conclusion we reach with greater than 99 percent confidence. We also show that global climate forcing by aerosols became stronger (increasingly negative) during 1970-2005, unlike IPCC’s best estimate of aerosol forcing. High confidence in these conclusions is based on a broad analysis approach. IPCC’s underestimates of climate sensitivity and aerosol cooling follow from their disproportionate emphasis on global climate modeling, an approach that will not yield timely, reliable, policy advice.
Des milliers de formulaires de candidature ont été dérobés. Parmi eux : le dossier de l’actuel prétendant démocrate à la mairie de New York, qui a été transmis à des médias.
Why is the Trump Administration trying to kill a small space science institute in New York City? Explanation begins with Galileo’s method of scientific inquiry and ends with the role of special interest money in the United States government. Galileo improved the telescope, allowing clearer observations of the planets and the Sun. Galileo differed from his peers, as he was unafraid to challenge authority. He claimed that the world should be understood based on observations, and he spoke directly to the public. He obtained philanthropic support for his observations and openly described the conclusion that Earth was not the center of the solar system – Earth revolved around the Sun.
La ministre de l’éducation américaine, Linda McMahon, reproche à l’université de ne pas avoir protégé les étudiants juifs du campus malgré des demandes en ce sens.