solar panels Bloomberg/Getty Images

Vers une planète plus réfléchie

CAMBRIDGE – La dernière fois que l’atmosphère a renfermé autant de dioxyde de carbone, c’était il y a environ trois millions d’années – époque à laquelle le niveau des océans était supérieur de 10-30 mètres à celui d’aujourd’hui. Les modèles climatiques aspiraient depuis bien longtemps à simuler ces importantes fluctuations qui caractérisent le niveau des mers – c’est désormais chose faite. En effet, pour la première fois, une remarquable modélisation climatique de la glace en Antarctique parvient à simuler ces variations majeures. Et cette brillante avancée scientifique nous apporte des nouvelles catastrophiques.

Ce nouveau modèle climatique révèle que la fonte des glaces, rien qu’en Antarctique, pourrait faire grimper le niveau des mers de pas moins d’un mètre d’ici la fin du siècle – soit bien au-dessus des prévisions formulées jusqu’à présent. Pire encore, il annonce que même en cas de réussite majeure dans la réduction des émissions de carbone, la calotte glacière de l’Antarctique occidental ne pourra être sauvée, signifiant en fin de compte à coup sûr une augmentation du niveau des mers de plus de cinq mètres. Or, une augmentation même d’un mètre pourrait mettre en péril des villes tout entières, de Miami à Dubaï, et provoquer des perturbations considérables sur le plan économique.

Il nous faut abaisser la température planétaire – et vite. Dans le cadre de cette démarche, la modification de l’albédo terrestre – sorte de géo-ingénierie consistant à refroidir la planète en augmentant la réflectivité présente dans l’atmosphère – constitue une formidable promesse.

To continue reading, please log in or enter your email address.

Registration is quick and easy and requires only your email address. If you already have an account with us, please log in. Or subscribe now for unlimited access.


Log in;
  1. Sean Gallup/Getty Images

    Angela Merkel’s Endgame?

    The collapse of coalition negotiations has left German Chancellor Angela Merkel facing a stark choice between forming a minority government or calling for a new election. But would a minority government necessarily be as bad as Germans have traditionally thought?

  2. Trump Trade speech Bill Pugliano/Getty Images .

    Preparing for the Trump Trade Wars

    In the first 11 months of his presidency, Donald Trump has failed to back up his words – or tweets – with action on a variety of fronts. But the rest of the world's governments, and particularly those in Asia and Europe, would be mistaken to assume that he won't follow through on his promised "America First" trade agenda.

  3. A GrabBike rider uses his mobile phone Bay Ismoyo/Getty Images

    The Platform Economy

    While developed countries in Europe, North America, and Asia are rapidly aging, emerging economies are predominantly youthful. Nigerian, Indonesian, and Vietnamese young people will shape global work trends at an increasingly rapid pace, bringing to bear their experience in dynamic informal markets on a tech-enabled gig economy.

  4. Trump Mario Tama/Getty Images

    Profiles in Discouragement

    One day, the United States will turn the page on Donald Trump. But, as Americans prepare to observe their Thanksgiving holiday, they should reflect that their country's culture and global standing will never recover fully from the wounds that his presidency is inflicting on them.

  5. Mugabe kisses Grace JEKESAI NJIKIZANA/AFP/Getty Images

    How Women Shape Coups

    In Zimbabwe, as in all coups, much behind-the-scenes plotting continues to take place in the aftermath of the military's overthrow of President Robert Mugabe. But who the eventual winners and losers are may depend, among other things, on the gender of the plotters.

  6. Oil barrels Ahmad Al-Rubaye/Getty Images

    The Abnormality of Oil

    At the 2017 Abu Dhabi Petroleum Exhibition and Conference, the consensus among industry executives was that oil prices will still be around $60 per barrel in November 2018. But there is evidence to suggest that the uptick in global growth and developments in Saudi Arabia will push the price as high as $80 in the meantime.

  7. Israeli soldier Menahem Kahana/Getty Images

    The Saudi Prince’s Dangerous War Games

    Saudi Arabia’s Crown Prince Mohammed bin Salman is working hard to consolidate power and establish his country as the Middle East’s only hegemon. But his efforts – which include an attempt to trigger a war between Israel and Hezbollah in Lebanon – increasingly look like the work of an immature gambler.