Arctic sea ice has declined at a rapid rate since the 1990s. Summer sea ice extent has declined by about 50% and sea ice thickness by about 40%. Arctic sea ice has thus moved into a new, more vulnerable regime with predominance of first-year ice, longer periods of open water, and enhanced surface melt rates. But – the Arctic is also subject to large natural variability, especially in the Atlantic sector; and a number of non-linear feedbacks play an important role in both enhancing and dampening the ice loss.
The mismatch between expected and observed rates of Arctic climate change is most clearly reflected by the fact that despite the progress, climate models are still unable to predict critical aspects of sea ice changes and their timing. This mismatch highlights the gap in our understanding of the underlying processes and feed- backs, as well as their realistic representation in climate models.
To ensure progress, Arctic ECRA recommends to:
- Maintain and enhance our European multi-disciplinary monitoring capabilities, which have been effective at detecting recent changes,
- Carry out dedicated joint observational and modelling campaigns to gain a better understanding of climate-relevant processes and ensure their accurate representation in climate models,
- Study natural variability of the Arctic climate system and its representation by models,
- Provide more reliable Arctic climate change predictions and projections to stakeholders based on the output of improved climate models, and
- Develop schemes that provide improved information of climate change uncertainty.
- Conduct further research into decadal scale variability to make reliable future predictions of Arctic sea ice