English references

Climate models show considerable discrepancies in their future projections around the Atlantic, mainly due to uncertainties in the fate of the Atlantic Meridional Overturning Circulation (AMOC). Climate models suggest a reduction in AMOC strength of 32 ± 37% by 2100 (90% probability, Shared Socioeconomic Pathways 2-4.5 scenario, Coupled Model Intercomparison Project Phase 6). To refine this estimate and reduce its uncertainty, we use four different observational constraint methods. The best one, which provides the lowest leave-one-out error, integrates a large set of observable variables using ridge-regularized linear regression—a method unusual in climate science. It gives an estimate of the AMOC slowdown of 51 ± 8% (90% probability), i.e., a weakening ∼ 60% stronger than suggested by the multimodel mean. This refinement mainly results from correcting a bias in South Atlantic surface salinity, consistent with recent studies emphasizing its role in the proximity to an AMOC tipping point. This more substantial

Exclusive: UCL scientists find large swathes of southern Europe are drying up, with ‘far-reaching’ implications

Much attention today focuses on uncertainties affecting the future evolution of oil and natural gas demand, with less consideration given to how the supply picture could develop. However, understanding decline rates – the annual rate at which production declines from existing oil and gas fields – is crucial for assessing the outlook for oil and gas supply and, by extension, for market balances. The International Energy Agency (IEA) has long examined this issue, and a detailed understanding of decline rates is at the heart of IEA modelling and analysis, underpinning the insights provided by the scenarios in the World Energy Outlook. This new report – based on analysis of the production records of around 15 000 oil and gas fields around the world – explores the implications of accelerating decline rates, growing reliance on unconventional resources, and evolving project development patterns for the global oil and gas supply landscape, for energy security and for investment. It also provides regional insights

The Implications of Oil and Gas Field Decline Rates

The Antarctic Circumpolar Current (ACC) is the world's strongest ocean current and plays a disproportionate role in the climate system due to its role as a conduit for major ocean basins. This current system is linked to the ocean's vertical overturning circulation, and is thus pivotal to the uptake of heat and CO2 in the ocean. The strength of the ACC has varied substantially across warm and cold climates in Earth's past, but the exact dynamical drivers of this change remain elusive. This is in part because ocean models have historically been unable to adequately resolve the small-scale processes that control current strength. Here, we assess a global ocean model simulation which resolves such processes to diagnose the impact of changing thermal, haline and wind conditions on the strength of the ACC. Our results show that, by 2050, the strength of the ACC declines by ∼20% for a high-emissions scenario. This decline is driven by meltwater from ice shelves around Antarctica, which is exported to lower latit

These powerful ‘rivers in the sky’ provide a huge share of annual precipitation in many regions, including California. They can also melt sea ice, with global climate implications.

Planetary Boundaries - summary and implications for policymakers 05.12.2022 Respecting planetary boundaries is essential to preserve the stability of ecosystems and human societies, including in Switzerland. Incorporating this principle into our legal system is consistent with the pursuit of our ...

Why do we always make the same mistake? Oh, that’s only trouble in the Balkans, we say – and then an assassination in Sarajevo sparks the first world war. Oh, Adolf Hitler’s threat to Czechoslovakia is “a quarrel in a faraway country, between people of whom we know nothing” – and then we find ourselves in the second world war. Oh, Joseph Stalin’s takeover of distant Poland after 1945 is none of our business – and soon enough we have the cold war. Now we have done it again, not waking up until it is too late to the full implications of Vladimir Putin’s seizure of Crimea in 2014. And so, on Thursday 24 February 2022, we stand here again, clothed in nothing but the shreds of our lost illusions.