Teleconnection from Arctic warming suppresses long-term warming in central Eurasia.

Whether the rapid warming of the Arctic, particularly the Barents-Kara Sea (BKS), substantially affects the Eurasian winter climate has been debated for over a decade. Here, we use an extended dynamical adjustment method to separate the effects of internal dynamics and thermodynamically forced BKS warming on atmospheric circulation, relying solely on observations. Evidence shows that the observed link between BKS warming and Eurasian cooling is influenced by both atmospheric internal variability and forced BKS warming.

Confronting Earth System Model trends with observations.

Anthropogenically forced climate change signals are emerging from the noise of internal variability in observations, and the impacts on society are growing. For decades, Climate or Earth System Models have been predicting how these climate change signals will unfold. While challenges remain, given the growing forced trends and the lengthening observational record, the climate science community is now in a position to confront the signals, as represented by historical trends, in models with observations.

Lessened projections of Arctic warming and wetting after correcting for model errors in global warming and sea ice cover.

Credible projections of Arctic warming and wetting (AWW) are essential for informed decision-making in a changing climate. However, current AWW projections from state-of-the-art climate models carry uncertainties. Using observational datasets and CMIP6 model simulations, we demonstrate that the observed historical global warming trend and the climatological mean pattern of Arctic sea ice can serve as effective constraints on AWW projections.

Models and observations agree on fewer and milder midlatitude cold extremes even over recent decades of rapid Arctic warming.

An apparent increase in observed cold extremes over recent decades in the northern midlatitudes has been reported, in contrast to robust decreases predicted by climate models. This discrepancy has led to suggestions that models fail to accurately simulate changes in weather patterns caused by Arctic warming. Here, we show that the observed frequency and intensity of midlatitude cold extremes have strongly decreased since 1990 and are consistent with modeled trends.

Global warming and arctic terns: Estimating climate change impacts on the world's longest migration.

Climate change is one of the top three global threats to seabirds, particularly species that visit polar regions. Arctic terns migrate between both polar regions annually and rely on productive marine areas to forage, on sea ice for rest and foraging, and prevailing winds during flight. Here, we report 21st-century trends in environmental variables affecting arctic terns at key locations along their Atlantic/Indian Ocean migratory flyway during the non-breeding seasons, identified through tracking data.

New climate models reveal faster and larger increases in Arctic precipitation than previously projected.

As the Arctic continues to warm faster than the rest of the planet, evidence mounts that the region is experiencing unprecedented environmental change. The hydrological cycle is projected to intensify throughout the twenty-first century, with increased evaporation from expanding open water areas and more precipitation. The latest projections from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) point to more rapid Arctic warming and sea-ice loss by the year 2100 than in previous projections, and consequently, larger and faster changes in the hydrological cycle.

Insignificant effect of Arctic amplification on the amplitude of midlatitude atmospheric waves.

Whether Arctic amplification has contributed to a wavier circulation and more frequent extreme weather in midlatitudes remains an open question. For two to three decades starting from the mid-1980s, accelerated Arctic warming and a reduced meridional near-surface temperature gradient coincided with a wavier circulation. However, waviness remains largely unchanged in model simulations featuring strong Arctic amplification.

Natural drivers of multidecadal Arctic sea ice variability over the last millennium.

The climate varies due to human activity, natural climate cycles, and natural events external to the climate system. Understanding the different roles played by these drivers of variability is fundamental to predicting near-term climate change and changing extremes, and to attributing observed change to anthropogenic or natural factors. Natural drivers such as large explosive volcanic eruptions or multidecadal cycles in ocean circulation occur infrequently and are therefore poorly represented within the observational record.

The missing Northern European winter cooling response to Arctic sea ice loss.

Reductions in Arctic sea ice may promote the negative phase of the North Atlantic Oscillation (NAO-). It has been argued that NAO-related variability can be used an as analogue to predict the effects of Arctic sea ice loss on mid-latitude weather. As NAO- events are associated with colder winters over Northern Europe, a negatively shifted NAO has been proposed as a dynamical pathway for Arctic sea ice loss to cause Northern European cooling.

The central role of diminishing sea ice in recent Arctic temperature amplification.

The rise in Arctic near-surface air temperatures has been almost twice as large as the global average in recent decades-a feature known as 'Arctic amplification'. Increased concentrations of atmospheric greenhouse gases have driven Arctic and global average warming; however, the underlying causes of Arctic amplification remain uncertain. The roles of reductions in snow and sea ice cover and changes in atmospheric and oceanic circulation, cloud cover and water vapour are still matters of debate.