Climate in Europe and the US could change much more radically than assumed 🌍

Winter weather forecasts for Europe and the eastern United States could change dramatically by the end of the century. A recent study sheds light on the concerning evolution of the North Atlantic Oscillation (NAO), a major climate phenomenon.

The NAO, this atmospheric seesaw between the Azores and Iceland, directly influences the strength of prevailing winds and winter conditions. Researchers from the Met Office and the University of Exeter have identified errors in current climate models related to water vapor, which obscure predictions.


These imperfections in simulations could mask the true scale of upcoming changes. The study reveals that the NAO reacts strongly to volcanic eruptions and greenhouse gases, with potentially devastating consequences.

Projections indicate an unprecedented intensification of the NAO under a high-emissions scenario. This would translate to increased risks of flooding and storm damage in Northern Europe, highlighting the urgency of reducing emissions.

The research team also highlighted the 'signal-to-noise paradox', suggesting that models may underestimate the actual changes in the NAO. This discovery calls for improvements in climate forecasting tools.

The implications of these findings are vast, particularly for preparing for extreme weather events. The authors stress the importance of not taking model projections at face value, at the risk of underestimating future impacts.

Finally, the study emphasizes the crucial role of mitigation efforts to limit the increase in the NAO and its impacts. A better understanding of atmospheric circulation's response to greenhouse gases is essential for anticipating climate changes.

What is the North Atlantic Oscillation?

The North Atlantic Oscillation (NAO) is a climate phenomenon resulting from the difference in atmospheric pressure between the Azores and Iceland. It influences weather conditions in Europe and North America, particularly in winter.

The NAO can manifest in two phases: a positive phase, associated with mild and wet winters in Northern Europe, and a negative phase, which brings colder and drier winters. These variations have direct impacts on agriculture, water resources, and flood risks.

The NAO mechanism is linked to global atmospheric circulation. Changes in the strength and position of prevailing winds, such as the jet stream, are key indicators of its activity.

Understanding the NAO is essential for improving seasonal weather forecasts and anticipating the impacts of climate change on affected regions.

Why do climate models underestimate NAO changes?

Current climate models have uncertainties in representing water vapor, a key factor in NAO dynamics. These errors can lead to underestimating future variations of this phenomenon.

The 'signal-to-noise paradox' illustrates this limitation. It suggests that models poorly capture the amplitude of actual NAO changes due to the complexity of atmospheric and oceanic interactions.

Volcanic eruptions and greenhouse gas concentrations are external factors influencing the NAO. Their integration into models requires increased accuracy to improve forecasts.

This highlights the need to develop more sophisticated models capable of better simulating climate processes and their impacts.