By Connor Letourneau , San Francisco Chronicle.  Excerpt: “When people fight the ocean,” [Pacifica, City Council member Christine] Boles said, “the ocean always wins.” ...Pacifica, a picturesque surf town of roughly 35,000 just south of San Francisco, has become an important case study for the increasingly urgent questions  climate change  raises for many coastal communities. Should residents stay to defend their homes from rising tides that grow fiercer by the year? Or, should they admit defeat and cede the land back to nature? ...“Managed retreat” — a term coined by geologists to describe the process of removing people, homes and businesses from at-risk areas — is at the root of the debate. ...“We can’t build seawalls high enough to protect us forever,” said Gary Griggs, a professor of Earth and planetary sciences at UC Santa Cruz. “So, in the long run, it’s either going to be managed retreat or unmanaged retreat. It’s up to each community to decide.”...  Full...

By Kimberly M. S. Cartier , Eos/AGU.  Excerpt: More than 3 billion people experienced their hottest year ever in 2024 because of anthropogenic climate change. The world is speeding toward its 1.5°C warming target. ...“Even if we likely exceeded [1.5°C] this year, that doesn’t mean that we’ve exceeded it in the context of the Paris accord, which is over a longer time period,” Schmidt said. “But I will say that we anticipate future global warming as long as we are emitting greenhouse gases, and until we get to net zero, we will not get a leveling off of global mean temperature.”....  Full article at https://eos.org/articles/exceptional-global-warming-spike-continued-in-2024 . 

By Laura Paddison , CNN.  Excerpt: It’s official: 2024 was the hottest year on record, breaking the  previous record  set in 2023 and pushing the world over a critical climate threshold, according to new data from Europe’s climate monitoring agency Copernicus [ https://climate.copernicus.eu/copernicus-2024-first-year-exceed-15degc-above-pre-industrial-level ]. Last year was 1.6 degrees hotter than the period before humans began burning large amounts of fossil fuels, Copernicus found. It makes 2024 the first calendar year to breach  the 1.5-degree limit  countries agreed to avoid under the Paris climate agreement in 2015. Scientists are much more concerned about breaches over decades, rather than single years — as above that threshold humans and ecosystems may struggle to adapt — but 2024’s   record   “does mean we’re getting dangerously close,” said Joeri Rogelj, a climate professor at Imperial College London....  Full article at https://www.cnn.c...

By Valério D. Pillar  and  Gerhard E. Overbeck , Science.  Excerpt: Over half of Earth’s land surface is covered with  fire-prone vegetation , with grassy ecosystems—such as grasslands, savannas, woodlands, and shrublands—being the most  extensive . In the context of the climate crisis, scientists worldwide are exploring  adaptation  measures to address the heightened fire risk driven by more frequent extreme climatic conditions such as droughts and heatwaves, as well as by  non-native plant invasions  that increased fuel loads and altered fire regimes. Although fire is intrinsic to  grassy ecosystems , rising exposure to wildfire smoke harms human health and the environment. Here, we argue that grazing management in grassy ecosystems could help reduce wildfire risk and its consequences....  Full article at https://www.science.org/doi/10.1126/science.adu7471 . 

By Christopher Bataille , Science.  Excerpt: According to current climate science, global temperatures will continue to rise until net carbon dioxide (CO 2 ) emissions reach zero ( 1 )—that is, when the amount of CO 2  added to the atmosphere is balanced by the amount removed. Given current projected emissions, 2 billion to 15 billion tonnes (Gt) of CO 2  may need to be removed from the atmosphere annually to meet the goal of the 2015 Paris Agreement to limit global warming below 2°C and preferably to 1.5°C above preindustrial temperatures ( 2 ,  3 ). ...Van Roijen  et al.  ( 4 ) report that replacing traditional building materials with CO 2 -storing alternatives could sequester carbon at the billion-tonne level. ...Building materials such as asphalt, wood, stone, steel, and concrete are foundational to human civilization and have large global demands, ...~30 Gt of concrete are used each year in the world ( 5 ). Some of these materials are also major c...

By Sarah Stanley , Eos/AGU.  Excerpt: The vast  Antarctic Ice Sheet  holds  more than half  of Earth’s freshwater. In several places around the continent, the ice extends over the ocean, where it forms large floating shelves. Observations suggest many of these  ice shelves are thinning  as they melt from below, with implications for ocean dynamics, global sea level, and Earth’s climate. For now, the  Filchner-Ronne Ice Shelf —one of Antarctica’s biggest, extending over the Weddell Sea—appears to be relatively stable, thanks to near-freezing currents circulating over the continental shelf beneath it. However, climate models predict that shifting ocean currents may bring warmer water to the continental shelf in the future. To gain a clearer picture of the Filchner-Ronne Ice Shelf’s future,  Steiger et al.  analyzed water temperature and velocity data from 2017 to 2021. ...In this study, researchers found that the summertime flow of warm wa...