Sélection du moment:
Breathless reporting on when the present global heat anomaly will begin to fall is understandable, given heat suffering around the world. However, fundamental issues are in question and a reflection on time scales is in order, for the sake of understanding ongoing climate change and actions that need to be taken.
Global temperature (12-month mean) is still rising at 1.56°C relative to 1880-1920 in the GISS analysis through April (Fig. 1). [Robert Rohde reports that it is 1.65°C relative to 1850-1900 in the BerkeleyEarth analysis.[3]] Global temperature is likely to continue to rise a bit for at least a month, peak this summer, and then decline as the El Nino fades toward La Nina. Acceleration of global warming is now hard to deny. The GISS 12-month temperature is now 0.36°C above the 0.18°C/decade trend line, which is 3.6 times the standard deviation (0.1°C). Confidence in global warming acceleration thus exceeds 99%, but we need to see how far temperature falls with the next La Nina before evaluating the post-2010 global warming rate.
Terwijl Oeganda honderden miljoenen donorgeld ontvangt voor bosbeheerprojecten zet een machtig houtkapsyndicaat, met tentakels in de regering, de woestijnvorming onverminderd voort. In Nigeria ruimt de overheid dan weer eigenhandig de bomen op. Intussen worden de lokale bevolkingen steeds armer.
A UN meeting this week considered a motion on a suite of technologies known as ‘solar radiation modification’, but no consensus could be reached on the controversial topic.
James Hansen affirme que la limite sera dépassée « à toutes fins utiles » d’ici au mois de mai, bien que d’autres experts prévoient que cela se produira dans les années 2030. Le seuil convenu au niveau international pour empêcher la Terre d’entrer dans une nouvelle ère de surchauffe sera « dépassé à toutes fins utiles » en 2024, a prévenu celui que l’on appelle le parrain de la science du climat. James Hansen, l’ancien scientifique de la Nasa à qui l’on doit d’avoir alerté le monde sur les dangers du changement climatique dans les années 80, a déclaré que le réchauffement planétaire causé par la combustion des combustibles fossiles, amplifié par le phénomène climatique El Niño qui se reproduit naturellement, fera grimper d’ici au mois de mai les températures jusqu’à 1,7 °C (3 °F) au-dessus de la moyenne enregistrée avant l’industrialisation.
James Hansen says limit will be passed ‘for all practical purposes’ by May though other experts predict that will happen in 2030s
Global warming is accelerating because the drive for warming, Earth’s energy imbalance, has doubled in the past decade. Measurement of the acceleration is hampered by unforced tropical (El Nino/La Nina) variability, but a good measuring stick is provided by warming between successive large El Ninos. Strengthening of the current (2023-24) El Nino has raised it to a level similar to the 1997-98 and 2015-16 El Ninos. The first six months of the current El Nino are 0.39°C warmer than the same six months of the 2015-16 El Nino, a global warming rate of 0.49°C/decade, consistent with expectation of a large acceleration of global warming. We expect the 12-month mean temperature by May 2024 to eliminate any doubt about global warming acceleration. Subsequent decline of the 12-month temperature below 1.5°C will likely be limited, confirming that the 1.5°C limit has already been passed.
James Hansen est un des plus grand climatologues du monde. Il a alerté le gouvernement des Etats-Unis sur le réchauffement climatique. Dans cette vidéo, les plus grands spécialistes actuels témoignent de l’excellence de ses prévisions climatiques. Il a aussi une énorme expérience du domaine. Je trouve son travail scientifique sur la montée du niveau de la mer publié en 2016 (lien, lien) très convaincant, plusieurs de ses conclusions et postulats ont été confirmés ces dernières années. Il se bat pour le climat depuis des décennies, et a été arrêté pour lors de manifestations pour le climat devant la Maison Blanche. Il a des grandes connaissances de climatologie. J’hésite donc réellement à le contredire mais j’ai quelques objections. Son travail apporte évidemment de nombreux éléments utiles, et il a le mérite d’être disponible aujourd’hui. Vu la situation climatique, nous ne pouvons pas attendre le prochain rapport du GIEC.
September 2023 smashed the prior global temperature record. Hand-wringing about the magnitude of the temperature jump in September is not inappropriate, but it is more important to investigate the role of aerosol climate forcing – which we chose to leave unmeasured – in global climate change. Global temperature during the current El Nino provides a potential indirect assessment of change of the aerosol forcing. Global temperature in the current El Nino, to date, implies a strong acceleration of global warming for which the most likely explanation is a decrease of human-made aerosols as a result of reductions in China and from ship emissions. The current El Nino will probably be weaker than the 1997-98 and 2015-16 El Ninos, making current warming even more significant. The current near-maximum solar irradiance adds a small amount to the major “forcing” mechanisms (GHGs, aerosols, and El Nino), but with no long-term effect. More important, the long dormant Southern Hemisphere polar amplification is probably com
Selon James Hansen – le scientifique des Etats-Unis qui a alerté le monde sur l’effet de serre dans les années 1980 – le monde est en train de basculer vers un climat surchauffé jamais vu l’existence de l’homme, parce que «nous sommes de sacrés imbéciles» pour ne pas avoir réagi aux avertissements concernant la crise climatique.
James Hansen, who testified to Congress on global heating in 1988, says world is approaching a ‘new climate frontier’
Improved knowledge of glacial-to-interglacial global temperature change implies that fastfeedback equilibrium climate sensitivity (ECS) is 1.2 ± 0.3°C (2σ) per W/m2 . Consistent analysis of temperature over the full Cenozoic era – including “slow” feedbacks by ice sheets and trace gases – supports this ECS and implies that CO2 was about 300 ppm in the Pliocene and 400 ppm at transition to a nearly ice-free planet, thus exposing unrealistic lethargy of ice sheet models. Equilibrium global warming including slow feedbacks for today’s human-made greenhouse gas (GHG) climate forcing (4.1 W/m2) is 10°C, reduced to 8°C by today’s aerosols. Decline of aerosol emissions since 2010 should increase the 1970-2010 global warming rate of 0.18°C per decade to a post-2010 rate of at least 0.27°C per decade. Under the current geopolitical approach to GHG emissions, global warming will likely pierce the 1.5°C ceiling in the 2020s and 2°C before 2050. Impacts on people and nature will accelerate as global warming pumps up hydr
Avatar, la voie de l’eau débute à la fin du premier film, après que les Na’vis, le peuple autochtone de la lune Pandora, se sont libérés de l’impérialisme humain. Une dizaine d’années s’écoulent avant que ces derniers ne reviennent avec des intentions toujours plus belliqueuses.
les SAF constituent l’arme de décarbonation massive de l’aviation mondiale, qui vise la neutralité carbone pour 2050. Ils pourraient à eux seuls représenter les deux tiers du chemin à parcourir. L’énergie électrique ? Pas assez performante pour espérer réduire fortement les émissions de CO2 des avions. L’hydrogène, porté par Airbus et son projet devant aboutir en 2035 ?
While this is not holiday cheer, I thought everyone should know about the following recent climate change research. James Hansen and 14 co-authors recently released a preprint (not yet peer reviewed) paper titled “Global Warming in the...
Cette étude est d’une importance majeure. Elle réévalue l’ampleur du réchauffement climatique à venir, réchauffement qui pourra aller, selon les auteurs, jusqu’à 10 ° C. Une valeur bien supérieure à celles estimées dans les pires scénarios du GIEC, et sur la seule base des quantités actuelles de GES émis jusqu’à ce jour… Makiko Sato, Leon Simons, Larissa S. Nazarenko, Karina von Schuckmann, Norman G. Loeb, Matthew B. Osman, Pushker Kharecha, Qinjian Jin, George Tselioudis, Andrew Lacis, Reto Ruedy, Gary Russell, Junji Cao, Jing Li ___ : ___ source : https://transitionecologique.org/2022/12/20/rechauffement-climatique-en-vue/
Improved knowledge of glacial-to-interglacial global temperature change implies that fast- feedback equilibrium climate sensitivity is at least ~4°C for doubled CO2 (2×CO2), with likely range 3.5-5.5°C. Greenhouse gas (GHG) climate forcing is 4.1 W/m2 larger in 2021 than in 1750, equivalent to 2×CO2 forcing. Global warming in the pipeline is greater than prior estimates. Eventual global warming due to today’s GHG forcing alone – after slow feedbacks operate – is about 10°C. Human-made aerosols are a major climate forcing, mainly via their effect on clouds. We infer from paleoclimate data that aerosol cooling offset GHG warming for several millennia as civilization developed. A hinge-point in global warming occurred in 1970 as increased GHG warming outpaced aerosol cooling, leading to global warming of 0.18°C per decade. Aerosol cooling is larger than estimated in the current IPCC report, but it has declined since 2010 because of aerosol reductions in China and shipping. Without unprecedented global actions to
Bruno Latour a le grand mérite d’avoir introduit en sciences sociales et philosophie les apports récents des sciences naturelles sur le fonctionnement du vivant, les questions écologiques et les questions fondamentales que cela pose. Je cherche à comprendre comment il reprend des découvertes scientifiques, que je connais bien par ailleurs, et comment il les reformule en questions philosophiques, de sciences sociales et dernièrement de politique.
Eleven of the 20 largest economies got a C or worse on a renewable energy report card, which assessed their plans to reach net zero and their targets for producing and using renewable energy
Peut-on sérieusement atteindre la neutralité carbone d'ici la fin du siècle ? Dans cet article retentissant, trois économistes du climat reviennent sur les principales étapes qui ont popularisé l'idée de compensation des émissions de CO2 comme moyen de limiter le réchauffement. Analysant les échecs successifs de cette approche pourtant hégémonique, ils montrent qu'elle repose sur des hypothèses technologiques de plus en plus extravagantes
The eyes of history will pierce the fog of politics. Science has exposed the course upon which our quest for energy has set our planet. Consequences will fall mainly on young people, their children, and grandchildren — unless decisive political leadership abandons wishful thinking and superficial half-measures. Climate change is a global matter and demands a global perspective.
Two of the UK’s leading hospitals have had to cancel operations, postpone appointments and divert seriously ill patients to other centres for the past three weeks after their computers crashed at the height of last month’s heatwave.
L’hypothèse de James Lovelock est que Gaïa est un superorganisme constitué de toute vie, y compris celle de Homo sapiens, qui règle la composition de l’air et de la température à la surface de la planète, dans les meilleures conditions, ce qui permet d’assurer la continuation de la vie. La régulation de la Planète par la biosphère est donc le point central de l’hypothèse controversée de Gaïa.
It’s hot and getting hotter. The first six months of the year are about 0.2°C cooler than the first six months of 2016 and 2020 (Fig. 1), but that’s only because the current La Nina continues to cool the tropics. Global temperature is rising despite the La Nina. Earth is out of energy balance (more solar energy absorbed than heat radiated to space) by an astounding amount – more than any time with reliable data – so, within a few years, we will be setting new global temperature records.
Le scientifique britannique James Lovelock, mort à 103 ans, était connu pour sa célèbre « hypothèse Gaïa ». À la croisée des disciplines, elle décrit la Terre comme capable de s’autoréguler.
L’environnementaliste britannique James Lovelock, connu pour avoir alerté avant l'heure sur la crise climatique et pour son "hypothèse Gaïa" présentant la terre comme un être vivant capable de s'autoréguler, est décédé à l'âge de 103 ans.
Le scientifique britannique James Lovelock, connu pour avoir alerté avant l’heure sur la crise climatique et pour son « hypothèse Gaïa » présentant la terre comme un être vivant capable de s’autoréguler, est décédé à l’âge de 103 ans, a indiqué mercredi 27 juillet sa famille.
The federal effort could set the stage for more studies into the feasibility, benefits and risks of one of the more controversial means of combating climate change.
What else is new? Hotspots are getting hotter. The major hotspot in April stretched from Iraq to India and Pakistan, and toward the northeast through Russia (Fig. 1). Temperature exceeded 45°C (113°F) in late April in at least nine Indian cities,[1] on its way to 50°C (122°F) in Pakistan in May,[2] where a laborer says “It’s like fire burning all around” and a meteorologist describing growing heatwaves since 2015 says “The intensity is increasing, and the duration is increasing, and the frequency is increasing.” Halfway around the world, Canada and north-central United States were cooler than their long-term average, but people in British Columbia and northwest United States remember being under their own record-breaking hotspot last summer.
Le 23 juin 1988, en pleine sécheresse outre-Atlantique, James E. Hansen s’adresse au Congrès des États-Unis. Son discours déclenche une vague d’intérêt pour le réchauffement climatique dans le monde. Le 23 juin 2008, devant la commission parlementaire sur l’indépendance énergétique et le réchauffement global de ce même Congrès, cet homme libre a lancé un nouveau cri d’alarme à ses compatriotes, qui choisiront, lors d’une élection décisive pour le sort de la planète, leur nouveau président dans quelques semaines.
The past season – meteorological NH winter, SH summer – was the 5th warmest Dec-Jan-Feb in the instrumental record, despite the continuing La Niña (the cold tongue in the equatorial Pacific). Most of Eurasia was remarkably warm, 2-5°C above normal. The winter seemed cold to many people in North America, but a very warm December (Fig. 1) made the season well above normal in the U.S.
There’s a new horse race in 2022. It’s one that we would rather lose than win. If our analysis is right, the world will probably blow through the 1.5°C global warming ceiling this decade; if we’re wrong, it could be delayed a decade. We argue[1],[2] that the apparent acceleration of global warming in the past decade is driven by an acceleration in the growth rate of human-made climate forcings, especially reduced human-made aerosol cooling – an effect that is not going away and may grow.
La planète Terre, la création, ce monde dans lequel la civilisation s’est développée, qui est doté de schémas climatiques que nous connaissons et de rivages stables, ce monde est en péril imminent. Ce n’est qu’au cours des dernières années que l’urgence de la situation s’est cristallisée. Nous disposons désormais de preuves évidentes de la crise, grâce aux informations toujours plus détaillées sur la manière dont la Terre a réagi, au fil de son histoire, aux forces perturbatrices : de manière très sensible, avec un certain décalage dû à l’inertie de la masse océanique.
On the holiday honoring the Rev. Martin Luther King Jr., scientists, theologians, ministers and climate justice advocates find commonality in the movement he led more than half a century ago.
October global temperature was close to an October record for the 1880-2021 period of near-global instrumental data (Fig. 1, left), despite the cooling effect of a fairly strong, double-dip La Nina (Fig. 1, right). The October global temperature – the 4th warmest October in the period 1880-present – was +1.23°C relative to 1880-1920.
Le célèbre scientifique pense que le Covid-19 est une des premières tentatives de la planète bleue pour se protéger de l'espèce humaine.
Covid-19 may well have been one attempt by the Earth to protect itself. Gaia will try harder next time with something even nastier
Pledges to plant trees fall from politicians’ lips like leaves in the autumn, especially during elections and climate summits. Yet ambitious government planting targets are likely to be missed because there are not enough trees or people to plant them, leading forestry figures have warned.
The UN Conference of the Parties (COP26) for the Framework Convention on Climate Change will be in Glasgow 1-12 November. There is a chance that Boris Johnson, UK Prime Minister and meeting host, might make this COP more effective than prior COPs, as discussed below.
Rooftop solar panels are up to 79% cheaper than they were in 2010. These plummeting costs have made rooftop solar photovoltaics even more attractive to households and businesses who want to reduce their reliance on electricity grids while reducing their carbon footprints. But are there enough rooftop surfaces for this technology to generate affordable, low-carbon energy for everyone who needs it?
Communications from young people give me optimism. Potential leaders among young people seem to have an ability to see the forest for the trees regarding climate change policy, a desire to follow the data, and a recognition of the need to address political polarization.
July global temperature (+1.16°C relative to 1880-1920 mean) was within a hair (0.02°C) of being the warmest July in the era of instrumental measurements (Fig. 1, left). That’s remarkable because we are still under the influence of a fairly strong La Nina (Fig. 1, right). Global cooling associated with La Ninas peaks five months after the La Nina peak,[1] on average.
Global temperature in June was +1.13°C (relative to the 1880-1920 base period, which is our best estimate of preindustrial temperature); it was +0.85°C relative to the 1951-1980 base period. High temperature anomalies were notable in northwest North America, northeast Siberia, and a horseshoe-shaped area covering much of Europe and western Asia (Fig. 1). The Pacific Northwest heatwave continued into July with daily temperatures exceeding prior records by several degrees, an extreme that merits discussion.
the sediments below oxygen-depleted waters are a significant source of nitrous oxide (N2O). This gas is released into the atmosphere when deep water rises to the surface in a process known as upwelling. Nitrous oxide, more commonly known as “laughing gas,” is a potent greenhouse gas, 300 times more powerful than carbon dioxide. Global emissions of N2O are increasing as a result of human activities that stimulate its production.
On Sunday this week Zakaria ended his program with a concise description of an effective approach to address climate change – in just a few minutes he described how carbon fee-and-dividend could be made near-global. I won’t try to summarize his take – it’s impossible to match his clarity and brevity, which includes great illustrations.
Editor’sNote: This essay by esteemed scientist James Hansen is a hybrid ofthe books’ foreword and an independent treatise on the accelerated warming of the planet
Throughout Earth's history, CO2 is thought to have exerted a fundamental control on environmental change. Here we review and revise CO2 reconstructions from boron isotopes in carbonates and carbon isotopes in organic matter over the Cenozoic—the past 66 million years. We find close coupling between CO2 and climate throughout the Cenozoic, with peak CO2 levels of ∼1,500 ppm in the Eocene greenhouse, decreasing to ∼500 ppm in the Miocene, and falling further into the ice age world of the Plio–Pleistocene. Around two-thirds of Cenozoic CO2 drawdown is explained by an increase in the ratio of ocean alkalinity to dissolved inorganic carbon, likely linked to a change in the balance of weathering to outgassing, with the remaining one-third due to changing ocean temperature and major ion composition. Earth system climate sensitivity is explored and may vary between different time intervals. The Cenozoic CO2 record highlights the truly geological scale of anthropogenic CO2 change: Current CO2 levels were last seen ar
The spread of electrical lighting is blocking out the stars and threatens the health of many species … including humans. Now our national parks plan to take back the night
Le 23 juin 1988, James Hansen, directeur du Goddard Institute for Space Studies (GISS), un laboratoire de la NASA, tirait déjà la sonnette d'alarme sur les conséquences du réchauffement climatique. 31 ans plus tard, son discours est plus d'actualité que jamais.
Humanity has swung a wrecking ball through the biosphere. We have chopped down over half of the world’s rainforests and by the middle of this century there may not be much more than a quarter left. This has been accompanied by a massive loss in biodiversity, such that the biosphere may be entering one of the great mass extinction events in the history of life on Earth.
Here are the real reasons we’re not building clean energy anywhere near fast enough.
By continuing to delay significant reductions in greenhouse gas emissions, we risk handing young people alive today a bill of up to US$535 trillion. This would be the cost of the “negative emissions” technologies required to remove CO₂ from the air in order to avoid dangerous climate change.
L’institut allemand Öko estime que l’UE devrait réduire de 94% les émissions des transports d’ici 2050 pour respecter l’accord de Paris. Les spécialistes de l’institut Öko, en Allemagne, préviennent que même une augmentation de deux degrés aurait un impact catastrophique, et parfois dangereux. L’accord de Paris, conclu pas les dirigeants du monde entier en décembre 2015, dans le cadre de la COP 21, prévoit de limiter le réchauffement climatique à deux degrés au-dessus du niveau préindustriel, voire moins.
Comment représenter au mieux l’évolution climatique en cours pour favoriser la réflexion sur la menacequ’elle représente ? James Hansen et Makiko Sato (Goddard Institute for Space Studies, Nasa) viennent demodifier leur traditionnel graphique montrant la courbe des températures de la planète depuis 1880. Ils n’ont pas changé la courbe elle même, mais la période de référence et également indiqué la moyenne glissante sur les 12 derniers mois.