/environment

  • Ocean spray emits more PFAS than industrial polluters, study finds
    https://www.theguardian.com/environment/2024/apr/19/ocean-spray-pfas-study
    Quand tu respires à pleins poumons en regardant la mer, il y a des chances que tu absorbes une bonne dose de PFAS.

    The study measured levels of #PFAS released from the bubbles that burst when waves crash, spraying #aerosols into the #air. It found sea spray levels were hundreds of thousands times higher than levels in the water.

    The contaminated spray likely affects groundwater, surface water, vegetation, and agricultural products near coastlines that are far from industrial sources of PFAS, said Ian Cousins, a Stockholm University researcher and the study’s lead author.

    There is evidence that the ocean can be an important source [of PFAS air emissions],” Cousins said. “It is definitely impacting the coastline.

    [...] It is unclear what the findings mean for human exposure. Inhalation of PFAS is an issue, but how much of the chemicals are breathed in, and air concentrations further from the waves, is still unknown.

    [...] He said that the results showed how the chemicals are powerful surfactants that concentrate on the surface of water, which helps explain why they move from the ocean to the air and atmosphere.

    We thought PFAS were going to go into the ocean and would disappear, but they cycle around and come back to land, and this could continue for a long time into the future,” he said.

    #pollution #plastique #océan

    • « (...) il n’est plus possible de traiter les profondeurs comme étant d’une manière ou d’une autre séparée de l’activité humaine. Il n’est pas non plus possible de le considérer simplement comme une nouvelle frontière à exploiter, comme le prévoient les projets d’exploitation minière en haute mer . Au lieu de cela, tout comme la découverte du temps profond a modifié la façon dont la culture occidentale comprenait la place de l’humanité dans l’histoire plus vaste de l’histoire de la Terre, reconnaître que les profondeurs sont intimement liées au reste de la planète exige un changement dans notre compréhension de l’échelle et de la complexité réelles. de la biosphère de notre planète et, par extension, le fait que l’avenir non seulement de la vie humaine, mais de toute vie sur Terre, est inextricablement lié aux profondeurs. » James Bradley, romancier et critique australien.

  • Cancer-causing PCB chemicals still being produced despite 40-year-old ban
    https://www.theguardian.com/environment/2024/mar/08/cancer-causing-pcb-chemicals-still-produced-despite-40-year-old-ban

    Research seen by the Guardian and Watershed Investigations shows that PCBs are being produced as byproducts in chemical reactions, which means small proportions of them are present in many chemicals used today.

    This is staggering given that production of PCBs was banned over 40 years ago and we are supposed to be eliminating them under the Stockholm convention,” said the environmental forensic scientist Dr Dave Megson from Manchester Metropolitan University, who conducted the study.

    When we take into account the volumes of these chemicals and the small levels of PCBs within them then this adds up to a massive number – around 45,000 tonnes per year in the US alone.” During peak commercial production in the 1970s about 39,000 tonnes were made each year, states the study.

    Most people associate this accidental production of PCBs with paints and pigments, but our research shows it’s much broader than that,” said Megson. Chlorinated solvents, which are used in chemical manufacturing, are a major source according to the research.

    PCBs are currently going undetected in many studies as the specific PCBs produced accidentally are different from the PCBs that were produced intentionally in the commercial mixtures of 50-plus years ago.”

    The study says these kinds of by-product PCBs are not measured in many existing monitoring programmes and may pose a “growing, unmonitored environmental and human health risk”. It suggests they should be classified as “a pollutant of emerging concern” and that they need to be addressed urgently as all PCBs are considered toxic, not just legacy PCBs from commercial mixtures.

    Lee Bell from the international chemicals NGO network who is also a member of the Stockholm convention PCB expert group said: “Not a lot of effort has been made in regulating unintentional production of PCB from chemical manufacture. In the case of intentional PCB production, the parties to the convention have a deadline to eliminate all stockpiles of old PCB by 2028. They are woefully behind on this task and about 80% of PCB stockpiles have yet to be destroyed."

    [...]

    “_It is disappointing that hundreds of millions of dollars are being spent to destroy legacy PCBs while regulators allow unintentional PCB contamination to spread virtually unabated.

    [...]

    PCB production was banned in the US in 1979 and in 1981 in the UK, and work to restrict their use in electrical equipment in the UK is continuing. Sources of legacy pollution from commercially made PCBs include landfills and materials in buildings.

    #PCB #pollution #Monsanto #biodiversité

  • Microplastics found in every human #placenta tested in study | Plastics | The Guardian
    https://www.theguardian.com/environment/2024/feb/27/microplastics-found-every-human-placenta-tested-study-health-impact

    Microplastics have been found in every human placenta tested in a study, leaving the researchers worried about the potential health impacts on developing foetuses.

    The scientists analysed 62 placental tissue samples and found the most common plastic detected was polyethylene, which is used to make plastic bags and bottles. A second study revealed microplastics in all 17 human arteries tested and suggested the particles may be linked to clogging of the blood vessels.

    #plastique

  • Move to sustainable food systems could bring $10tn benefits a year, study finds

    Existing production destroys more value than it creates due to medical and environmental costs, researchers say

    A shift towards a more sustainable global food system could create up to $10tn (£7.9tn) of benefits a year, improve human health and ease the climate crisis, according to the most comprehensive economic study of its type.

    It found that existing food systems destroyed more value than they created due to hidden environmental and medical costs, in effect, borrowing from the future to take profits today.

    Food systems drive a third of global greenhouse gas emissions, putting the world on course for 2.7C of warming by the end of the century. This creates a vicious cycle, as higher temperatures bring more extreme weather and greater damage to harvests.

    Food insecurity also puts a burden on medical systems. The study predicted a business-as-usual approach would leave 640 million people underweight by 2050, while obesity would increase by 70%.

    Redirecting the food system would be politically challenging but bring huge economic and welfare benefits, said the international team of authors behind the study, which aims to be the food equivalent of the Stern review, the 2006 examination of the costs of climate change.

    Johan Rockström, of the Potsdam Institute for Climate Impact Research and one of the study’s authors, said: “The global food system holds the future of humanity on Earth in its hand.”

    The study proposes a shift of subsidies and tax incentives away from destructive large-scale monocultures that rely on fertilisers, pesticides and forest clearance. Instead, financial incentives should be directed towards smallholders who could turn farms into carbon sinks with more space for wildlife.

    A change of diet is another key element, along with investment in technologies to enhance efficiency and cut emissions.

    With less food insecurity, the report says, undernutrition could be eradicated by 2050, with 174 million fewer premature deaths, and 400 million farm workers able to earn a sufficient income. The proposed transition would help to limit global heating to 1.5C above pre-industrial levels and halve nitrogen run-offs from agriculture.

    Overall, they estimate the costs of the transformation at between 0.2% and 0.4% of global GDP per year.

    In early research, Rockström and his colleagues found food was the largest sector of the economy breaching planetary boundaries. As well at the climate impact, it is a major driver of land-use change and biodiversity decline, and is responsible for 70% of freshwater drawdown.

    The report was produced by the Food System Economics Commission, which has been formed by the Potsdam Institute, the Food and Land Use Coalition, and EAT, a holistic food-system coalition of the Stockholm Resilience Centre, the Wellcome Trust and the Strawberry Foundation. Academic partners include the University of Oxford and the London School of Economics.

    It estimated the hidden costs of food, including climate change, human health, nutrition and natural resources, at $15tn, and created a new model to project how these hidden costs could develop over time, depending on humanity’s ability to change. Their calculations were in line with a report last year by the United Nations Food and Agriculture Organization, which estimated off-books agrifood costs at more than $10trillion globally in 2020.

    Dr Steven Lord, of the University of Oxford’s Environmental Change Institute, said in a statement: “This analysis puts a first figure on the regional and global economic opportunity in transforming food systems. While not easy, the transformation is affordable on a global scale and the accumulating costs into the future of doing nothing pose a considerable economic risk.”

    Numerous other studies have demonstrated the health and climate benefits of a shift towards a plant-based diet. A report last year by the Climate Observatory notes that Brazil’s beef industry – and its related deforestation – now has a bigger carbon footprint than all the cars, factories, air conditioners, electric gadgets and other sources of emissions in Japan.

    The new study is not prescriptive about vegetarianism, but Rockström said demand for beef and most other meat would fall if hidden health and environmental costs were included in the price.

    Nicholas Stern, the chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics, welcomed the study: “The economics of today’s food system are, sadly, broken beyond repair. Its so-called ‘hidden costs’ are harming our health and degrading our planet, while also worsening global inequalities. Changing the ways we produce and consume food will be critical to tackling climate change, protecting biodiversity, and building a better future. It is time for radical change.”

    The main challenge of the proposed food transition is that costs of food would rise. Rockström said this would have to be handled with political dexterity and support for poor sections of society otherwise the result could be protests, such as the gilets jaunes (yellow vests) demonstrations held in France over petrol price hikes.

    Christiana Figueres, the former executive secretary of the UN Framework Convention on Climate Change, emphasised the forward-looking nature of the report: “This research … proves that a different reality is possible, and shows us what it would take to turn the food system into a net carbon sink by 2040. This opportunity should capture the attention of any policymaker who wants to secure a healthier future for the planet and for people.”

    https://www.theguardian.com/environment/2024/jan/29/sustainable-food-production-economic-benefits-study?CMP=share_btn_tw

    #système_alimentaire #alimentation #agriculture #coût #bénéfices #économie #agriculture_biologique #

    • The Economics of the Food System Transformation

      The text emphasizes the urgent need for a transformation of food systems, highlighting the economic, environmental, and social benefits of such a transformation. It outlines the negative impacts of current food systems on health, the environment, and climate change, identifying unaccounted costs estimated at 15 trillion USD a year. The report also discusses the unsustainable trajectory of the global food system and the potential economic benefits of a transformation, estimating them to be worth 5 to 10 trillion USD a year.

      Proposed Solutions for Food System Transformation:

      1. Shifting consumption patterns towards healthy diets: The report suggests regulating the marketing of unhealthy foods to children, providing front-of-pack nutritional guidance, targeting public food procurement on healthy options, taxing sugar-sweetened beverages and unhealthy foods, and reformulating packaged food to encourage healthier dietary choices.

      2. Resetting incentives by repurposing government support for agriculture: It is recommended to repurpose subsidies to improve access to healthy diets and make them more affordable. This involves reforming agricultural support to incentivize choices in line with the goals of the food system transformation, with a focus on lowering the hidden costs of food systems.

      3. Targeting revenue from new taxes to support food system transformation: The report recommends taxing carbon and nitrogen pollution to help achieve positive outcomes and align with expert recommendations from bodies such as the IPCC and OECD. Designing new taxes to suit the local context and targeting resulting revenues towards direct and progressive benefits for poorer households is essential to ensure inclusive outcomes and garner political support for a food system transformation.

      4. Innovating to increase labor productivity and workers’ livelihood opportunities: Public institutions can accelerate the development and diffusion of innovations that meet the needs of poorer producers and remove barriers to their adoption. Priority areas for public research and innovation include improving plant breeding, supporting environmentally sustainable, biodiversity-friendly, and low-emission farming systems, and developing digital technologies useful to small farmers.

      5. Scaling-up safety nets to keep food affordable for the poorest: Developing and strengthening safety nets is crucial to making food system transformations inclusive and politically feasible. Countries should prioritize targeting limited transfer resources on children’s nutritional needs and mobilizing more resources to put in place comprehensive safety nets.

      Additionally, the report addresses various tensions and obstacles in transforming food systems, highlighting the need to manage concerns such as fears of food price rises, job losses, policy siloes, global inequalities, and entrenched vested interests. It emphasizes the importance of addressing these concerns to facilitate change and ensure that the benefits of food system transformation can be realized. The report also highlights the rising visibility of transforming food systems as a policy priority, as well as the new ambition to seize the opportunities offered by such transformation, as evidenced by the COP28 UAE declaration on Sustainable Agriculture, Resilient Food Systems, and Climate Action signed by over 150 countries.

      https://knowledge4policy.ec.europa.eu/publication/economics-food-system-transformation_en
      https://foodsystemeconomics.org/wp-content/uploads/FSEC-Global_Policy_Report.pdf
      #rapport #coûts_cachés #pauvreté

  • Cop28 president says there is ‘no science’ behind demands for phase-out of fossil fuels
    https://www.theguardian.com/environment/2023/dec/03/back-into-caves-cop28-president-dismisses-phase-out-of-fossil-fuels

    The president of Cop28, Sultan Al Jaber, has claimed there is “no science” indicating that a phase-out of fossil fuels is needed to restrict global heating to 1.5C, the Guardian and the Centre for Climate Reporting can reveal.

    Al Jaber also said a phase-out of fossil fuels would not allow sustainable development “unless you want to take the world back into caves”.

    #climat

  • Microplastic-eating plankton may be worsening crisis in oceans, say scientists | Marine life | The Guardian
    https://www.theguardian.com/environment/2023/nov/09/microplastic-eating-plankton-worsening-crisis-oceans-plastic-pollution

    Phytoplankton found in marine and fresh water can ingest and break down microplastics, scientists have discovered. But rather than providing a solution to the threat plastics pose to aquatic life, the tiny creatures known as rotifers could be accelerating the risk by splitting the particles into thousands of smaller and potentially more dangerous nanoplastics.

    #plancton #rotifères #plastiques #nano

  • Allegations of extensive sexual abuse at Kenyan offsetting project used by Shell and Netflix
    https://www.theguardian.com/environment/2023/nov/07/accusations-of-widespread-sexual-abuse-at-offsetting-project-used-by-ne

    Male staff at a leading Kenyan carbon-offsetting project used by Netflix, Shell and other large companies have been accused of extensive sexual abuse and harassment over more than a decade, following an investigation by two NGOs.

    The Kasigau Corridor conservation project in southern Kenya, operated by the California-based firm Wildlife Works, generates carbon credits by protecting dryland forests at risk of being destroyed in key elephant, lion and wildlife habitats west of Mombasa. The scheme was the first ever forest protection scheme approved by Verra, the world’s leading certifier of carbon offsets, and has also been accredited for its biodiversity and community benefits, probably generating millions of dollars in revenue in carbon-credit sales.

    #crédits_carbone #violence_sexuelle

  • Revealed: the industry figures behind ‘declaration of scientists’ backing meat eating
    https://www.theguardian.com/environment/2023/oct/27/revealed-industry-figures-declaration-scientists-backing-meat-eating

    A public statement signed by more than 1,000 scientists in support of meat production and consumption has numerous links to the livestock industry, the Guardian can reveal. The statement has been used to target top EU officials against environmental and health policies and has been endorsed by the EU agriculture commissioner.

    #lobbying

  • EU abandons promise to ban toxic chemicals in consumer products | PFAS | The Guardian
    https://www.theguardian.com/environment/2023/oct/16/eu-abandons-promise-ban-toxic-chemicals-consumer-products

    Exclusive: Plan to outlaw all but the most vital of harmful chemicals is not included in leaked policy proposals

    Exclusif, l’Europe abandonne toute idée de progrès. Nous sommes en Guerre contre le reste du monde, et en premier lieu, donc, contre notre population.

  • Experts fear US carbon capture plan is ‘fig leaf’ to protect fossil fuel industry | Fossil fuels | The Guardian
    https://www.theguardian.com/environment/2023/aug/11/us-government-biden-carbon-capture

    The Biden administration delivered a historic climate bill last August though the president’s record on the climate has been undercut by his aggressive giveaway of oil and gas drilling leases on public land, including the controversial Willow oil project in Alaska.

    #climat #états-unis #foutage_de_gueule

    • The US energy department has announced it is awarding up to $1.2bn to two projects to directly remove carbon dioxide from the air, a fledgling technology that some climate experts worry will distract and undermine efforts to phase out fossil fuels.

      #DAC (direct air capture)

    • The chief executive of Occidental Petroleum, one of the largest U.S. oil companies, touted its $1 billion-plus project in West Texas to remove carbon dioxide directly from the air [...]

      We believe that our direct capture technology is going to be the technology that helps to preserve our industry over time,” [Occidental CEO Vicki] Hollub told the audience. “This gives our industry a license to continue to operate for the 60, 70, 80 years that I think it’s going to be very much needed.”

      https://www.politico.com/news/2023/03/08/oil-industry-shift-climate-tech-00085853

  • Gulf stream could collapse as early as 2025, study suggests | Climate crisis | The Guardian
    https://www.theguardian.com/environment/2023/jul/25/gulf-stream-could-collapse-as-early-as-2025-study-suggests
    https://i.guim.co.uk/img/media/c48440be715898be21be5636ac64d179db67ec45/0_0_3500_2102/master/3500.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Prof Niklas Boers, from the Potsdam Institute for Climate Impact Research in Germany, revealed the early warning signs of Amoc collapse in 2021. “The results of the new study sound alarming but if the uncertainties in the heavily oversimplified model [of the tipping point] and in the underlying [sea temperature] data are included, then it becomes clear that these uncertainties are too large to make any reliable estimate of the time of tipping.”

    Prof David Thornalley, at University College London, UK, agreed the study had large caveats and unknowns and said further research was essential: “But if the statistics are robust and a relevant way to describe how the actual Amoc behaves, then this is a very concerning result.”

    Dr Levke Caesar, at the University of Bremen, Germany, said using sea surface temperatures as proxy data for the strength of the Amoc currents was a key source of uncertainty: “We only have direct observational data of the Amoc since 2004.”

    The extrapolation in the new analysis was reasonable, according to Prof Tim Lenton, at the University of Exeter, UK. He said the tipping point could lead to a partial Amoc collapse, for example only in the Labrador Sea, but that this would still cause major impacts. Divlitsen said he hoped the debate would drive new research: “It’s always fruitful when you do not exactly agree.”

    Prof Stefan Rahmstorf, at the University of Potsdam, Germany, said: “There is still large uncertainty where the Amoc tipping point is, but the new study adds to the evidence that it is much closer than we thought. A single study provides limited evidence, but when multiple approaches have led to similar conclusions this must be taken very seriously, especially when we’re talking about a risk that we really want to rule out with 99.9% certainty. Now we can’t even rule out crossing the tipping point in the next decade or two.”

    • le titre de l’article est trompeur (Gulf stream en lieu et place d’AMOC)

      Le Gulf Stream va-t-il sauver l’Europe du changement climatique ?
      https://bonpote.com/le-gulf-stream-va-t-il-sauver-leurope-du-changement-climatique

      Après avoir quitté la côte américaine, une partie de l’eau transportée par le #Gulf_Stream (de l’ordre de 20 %) circule, en surface, vers le nord, puis traverse le bassin d’ouest en est vers 50°N. Ensuite elle rejoint soit les mers d’Irminger et du Labrador qui entourent la pointe Sud du Groenland, soit encore plus au nord les côtes norvégiennes.

      La chaleur transportée est transférée dans l’atmosphère, surtout en hiver, ce qui rend l’eau en surface plus lourde. C’est pourquoi dans ce parcours, elle a tendance à “couler” en profondeur où elle alimente les courants profonds qui s’orientent en moyenne vers le sud.

      Dans l’ensemble, cette circulation occupe tout l’#océan_Atlantique, et s’oriente vers le nord proche de la surface et vers le sud en profondeur, ce qui décrit une boucle de retournement, d’où la dénomination française de circulation de retournement (et en anglais #AMOC pour Atlantic Meridional Overturning Circulation).

      Ce qu’il faut surtout retenir, c’est que cette circulation n’est pas un seul courant, mais une moyenne, une construction mathématique qui regroupe, fusionne plusieurs courants différents dans tout l’Atlantique Nord, dont le Gulf Stream. Sa définition ne s’arrête pas à l’équateur : on la calcule aussi dans l’hémisphère sud et dans tous les autres bassins.

      Comment connaît-on ces phénomènes et comment les étudie-t-on ?
      Comment observe-t-on le Gulf Stream ?

      Le Gulf Stream, courant océanique bien connu des marins depuis le XVIème siècle et dont la température chaude est mesurée dès le XVIIIème par Benjamin Franklin, est observé régulièrement par des navires océanographiques depuis bientôt un siècle. On mesure son intensité en continu grâce à un câble sous-marin entre la Floride et les Bahamas depuis les années 1980. On l’observe par satellite depuis les années 1990. La situation n’a rien de comparable pour la circulation de retournement…

      Comment observe-t-on la circulation de retournement ?
      Depuis 2004, un ensemble d’instruments océanographiques sont disposés le long d’une ligne imaginaire qui relie la côte Est des États-Unis à l’Afrique à la latitude 26°N, de la surface jusqu’au fond de l’océan. Cette section océanographique permet de mesurer en continu l’intensité de la circulation de retournement.

      Parce que ces observations directes restent peu nombreuses, les océanographes ont beaucoup recours aux modèles numériques pour étudier la circulation de retournement et ses impacts. Ces outils, basés sur la mécanique des fluides, les mathématiques et les sciences du calcul intensif, permettent de réaliser des expériences virtuelles pour tester des hypothèses (quel serait l’impact sur le climat en Europe d’un arrêt de la circulation de retournement ?) et tenter de reproduire les océans actuels, passés et futurs.

      Enfin, les paléo-océanographes essaient de reconstruire les fluctuations de la circulation de retournement en utilisant des mesures indirectes de son intensité, estimées à partir de divers prélèvements sédimentaires terrestres et marins.

      Historiquement, on pensait que la circulation de retournement était entraînée presque exclusivement par les contrastes, liés à la température et la salinité (d’où la dénomination de circulation “thermohaline”). On sait maintenant que d’autres processus physiques l’influencent, comme le vent et le mélange océanique.

      On sait aussi, notamment grâce aux modèles numériques et aux mesures directes récentes, qu’elle fluctue beaucoup d’un mois sur l’autre, d’un an sur l’autre, d’une décennie sur l’autre, d’un siècle sur l’autre… et que ces fluctuations peuvent être déclenchées par de nombreux processus différents (parmi lesquels la fonte du Groenland, mais pas que…).

      L’un des courants marins les plus complexes au monde
      Le Gulf Stream est également lui-même un des courants marins les plus complexes au monde car sous influence de multiples processus. La circulation de retournement hérite de cette complexité. Mais en tant que construction mathématique qui fusionne plusieurs courants marins dont le Gulf Stream, elle est aussi influencée par d’autres processus océaniques.

      On entend parfois que la circulation de retournement n’existe pas car les mesures RAPID à 26°N ne correspondent pas à celles prises plus au sud ou plus au nord. Ces différences, au contraire, illustrent bien que la circulation de retournement n’est pas un simple tapis roulant qui connecte l’océan Atlantique du sud au nord, comme des représentations simplifiées de l’océan ont pu le laisser à penser.

    • Scientists have long seen the Atlantic Meridional Overturning Circulation, or AMOC, as one of the planet’s most vulnerable “tipping elements” — meaning the system could undergo an abrupt and irreversible change, with dramatic consequences for the rest of the globe.
      Under Earth’s current climate, this aquatic conveyor belt transports warm, salty water from the tropics to the North Atlantic, and then sends colder water back south along the ocean floor. But as rising global temperatures melt Arctic ice, the resulting influx of cold freshwater has thrown a wrench in the system — and could shut it down entirely.

      https://www.washingtonpost.com/climate-environment/2023/07/25/atlantic-ocean-amoc-climate-change

      #AMOC : Atlantic Meridional Overturning Circulation (Circulation méridienne de retournement de l’Atlantique)

    • Les effets estimés d’un arrêt de l’AMOC :


      À gauche les températures, à droite les précipitations. À noter que ces valeurs sont une moyenne annuelle, or un des effets de l’arrêt de l’AMOC notamment dans les hautes latitudes serait un renforcement de la saisonnalité, chose qui n’est pas reflétée par les valeurs annuelles.
      L’Europe serait « sibérianisée », avec des hivers nettement plus longs (car commençant plus tôt) et plus froids (surtout en Europe du Nord), des étés plus courts (mais pas forcément plus frais), et des pluies en diminution (jusqu’à moitié moins sur la péninsule ibérique) car un Atlantique Nord plus froid évaporerait moins. On estime que la surface cultivable en blé et maïs en Europe serait réduite de plus de moitié.
      En Amérique du Nord il y aurait augmentation de la pluviométrie mais sous forme de tempêtes plus fréquentes.
      En Afrique de l’Ouest la zone très peuplée entre Sénégal et Gabon subirait une sécheresse et un réchauffement accrus (car la chaleur n’étant plus transportée vers le nord s’accumulerait dans les tropiques)
      Tout l’hémisphère Sud se réchaufferait, et la forêt amazonienne disparaîtrait encore plus vite sous l’effet de sécheresses accentuées (en relarguant son carbone au passage).
      Les courants de Humbolt (Chili Pérou) et du Benguéla (Namibie Angola) s’affaibliraient, la pêche dans ces secteurs (très importante aujourd’hui) ne donnerait plus grand chose, et l’océan global perdrait beaucoup de sa productivité et de sa capacité à absorber le CO2. Maigre consolation les déserts d’Atacama et du Namib seraient moins désertiques, le Nord-Est brésilien moins aride, mais probablement pas de quoi accueillir des centaines de millions de réfugiés climatiques.

    • d’après cette simulation la Méditerranée et l’Afrique du Nord seraient également touchées par le refroidissement de l’Atlantique Nord, la chaleur resterait piégée plus au Sud. Si on y ajoute la baisse des précipitations dans tout le pourtour méditerranéen, le Sahara s’étendrait en quelque-sorte à la fois sur le Maghreb et sur le Sahel.

  • [en attendant la révolution sociale] Vegan diet massively cuts environmental damage, study shows | Food | The Guardian
    https://www.theguardian.com/environment/2023/jul/20/vegan-diet-cuts-environmental-damage-climate-heating-emissions-study

    Detailed analysis finds plant diets lead to 75% less climate-heating emissions, water pollution and land use than meat-rich ones

    Eating a vegan diet massively reduces the damage to the environment caused by food production, the most comprehensive analysis to date has concluded.

    The research showed that vegan diets resulted in 75% less climate-heating emissions, water pollution and land use than diets in which more than 100g of meat a day was eaten. Vegan diets also cut the destruction of wildlife by 66% and water use by 54%, the study found.

    The heavy impact of meat and dairy on the planet is well known, and people in rich nations will have to slash their meat consumption in order to end the climate crisis. But previous studies have used model diets and average values for the impact of each food type.

    In contrast, the new study analysed the real diets of 55,000 people in the UK. It also used data from 38,000 farms in 119 countries to account for differences in the impact of particular foods that are produced in different ways and places. This significantly strengthens confidence in the conclusions.

    However, it turned out that what was eaten was far more important in terms of environmental impacts than where and how it was produced. Previous research has shown that even the lowest-impact meat – organic pork – is responsible for eight times more climate damage than the highest-impact plant, oilseed.

    Algal cells under a microscope
    Scientists find vital missing ingredient for healthy vegan diet – algae
    Read more
    The researchers said the UK should introduce policies to help people reduce the amount of meat they eat in order to meet the nation’s climate targets. Ministers have repeatedly said they will not tell people what to consume, despite the precedent of, for example, taxes on high-sugar drinks.

    Prof Peter Scarborough at Oxford University, who led the research, published in the journal Nature Food, said: “Our dietary choices have a big impact on the planet. Cutting down the amount of meat and dairy in your diet can make a big difference to your dietary footprint.”

    The global food system has a huge impact on the planet, emitting a third of the total greenhouse gas emissions driving global heating. It also uses 70% of the world’s freshwater and causes 80% of river and lake pollution. About 75% of the Earth’s land is used by humans, largely for farming, and the destruction of forests is the major cause of the huge losses in biodiversity.

    Prof Neil Ward at the University of East Anglia said: “This is a significant set of findings. It scientifically reinforces the point made by the Climate Change Committee and the National Food Strategy over recent years that dietary shifts away from animal-based foods can make a major contribution to reducing the UK’s environmental footprint.”

    The study also showed that low-meat diets – less than 50g a day – had half the impact of high-meat diets on greenhouse gas emissions, water pollution and land use. However, the differences between low-meat, pescetarian and vegetarian diets were relatively small.

    Prof Richard Tiffin at the University of Reading said: “This study represents the most comprehensive attempt to link food consumption data to the data on the environmental impacts of food production.

    “Encouraging high-meat-eaters to reduce meat consumption and encouraging vegetarians to become vegans should result in lower emissions,” he said. “However, it’s hard to justify changes to the diets of moderate omnivores on the basis of these results, other than to switch to a completely vegan diet.”

    The researchers who conducted the new study said diets enabling global food production to be sustainable would mean people in rich nations “radically” reducing meat and dairy consumption.

    They said other ways of reducing the environmental impact of the food system, such as new technology and cutting food waste, would not be enough.

    The biggest difference seen in the study was for emissions of methane, a potent greenhouse gas produced by cattle and sheep, which were 93% lower for vegan diets compared with high-meat diets.

    The UK Health Alliance on Climate Change recommended in 2020 that sustainable diets should be supported by mandatory environmental labelling on foods, regulation of promotions and taxation of high-carbon foods.

    A government spokesperson said: “People should make their own decisions around the food they eat. Achieving the net-zero target is a priority, and whilst food choices can have an impact on greenhouse gas emissions, well-managed livestock also provide environmental benefits such as supporting biodiversity, protecting the character of the countryside, and generating important income for rural communities.”

    The farming minister, Mark Spencer, said last week that he would like to see genetically modified cows that emit less methane.

  • Europe should cap ‘luxury’ energy use to meet emissions targets, study says | Energy | The Guardian
    https://www.theguardian.com/environment/2023/jul/17/europe-cap-luxury-energy-use-emissions-carbon-budget-targets-study
    https://i.guim.co.uk/img/media/af4b55a2fabe50fffc6246cf77e4e0eccd9b9744/1308_844_4304_2582/master/4304.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Gently limiting “luxury” demand from the 20% of European consumers who use the most energy saves seven times the amount of planet-heating gases that would be emitted in meeting the basic needs of the 20% who use the least energy, researchers have found.

    The study, which modelled the effect of narrowing the gaps in energy use between households within 27 European countries, found capping demand from the top fifth, even at a fairly high level, cut greenhouse gas pollution from energy consumption by 9.7%, while raising demand from people in the bottom fifth who also live in poverty to a fairly low level increases emissions by just 1.4%.

    “We have to start tackling luxury energy use to stay within an equitable carbon budget for the globe,” said Milena Buchs, a professor of sustainable welfare at the University of Leeds and the lead author of the study, published on Monday in the journal Nature Energy, “but also to actually have the energy resources to enable people in fuel poverty to slightly increase their energy use and meet their needs.”

    To stop the planet heating beyond the levels agreed to by world leaders, rich countries must quickly clean up their supply of energy and cut demand for it. The Intergovernmental Panel on Climate Change (IPCC) found in its latest review of the science that demand-side strategies can slash global emissions 40-70% by 2050 compared with business as usual.

  • Will El Niño on top of global heating create the perfect climate storm? | Climate crisis | The Guardian
    https://www.theguardian.com/environment/2023/jul/03/a-perfect-storm-scientists-ponder-if-climate-has-entered-a-new-erratic-
    https://i.guim.co.uk/img/media/3de9780af1df091c9318b572fa4ef2183fb7f2c3/0_0_4936_2962/master/4936.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Very unusual”, “worrying”, “terrifying”, and “bonkers”; the reactions of veteran scientists to the sharp increase in north Atlantic surface temperatures over the past three months raises the question of whether the world’s climate has entered a more erratic and dangerous phase with the onset of an El Niño event on top of human-made global heating.

    Since April, the warming appears to have entered a new trajectory. Meanwhile the area of global sea ice has dropped by more than 1 million sq km below the previous low.

    “If a few decades ago, some people might have thought climate change was a relatively slow-moving phenomenon, we are now witnessing our climate changing at a terrifying rate,” said Prof Peter Stott, who leads the UK Met Office’s climate monitoring and attribution team. “As the El Niño builds through the rest of this year, adding an extra oomph to the damaging effects of human-induced global heating, many millions of people across the planet and many diverse ecosystems are going to face extraordinary challenges and unfortunately suffer great damage.”

  • Pesticide firms withheld brain toxicity studies from EU regulators, study finds | Pesticides | The Guardian
    https://www.theguardian.com/environment/2023/jun/01/pesticide-firms-withheld-brain-toxicity-studies-from-eu-regulators-stud

    En toute #impunité

    Apolline Roger, a lawyer at ClientEarth, contrasted the lack of penalties for non-disclosure of toxicity studies with those imposed for breaches of EU data protection and competition laws, which can lead to fines of significant percentages of a company’s annual turnover.

    “You don’t have [penalties] like that for this process, even though what is at stake is the dispersion of potentially very harmful substances in the environment, and therefore in our food, water and bodies,” she said. “What does it say about us when we place a higher value on digital data and consumer protection than on health and the environment?”

    #sans_vergogne #pesticides #ue