Arctic lands and water aren’t what they used to be. Redfern says conditions are less predictable. Annual freeze-ups are happening later, and breakups earlier. Places where ice was once frozen solid are now more precarious. All this is a grim reminder that the consequences of climate change are being felt right now. On Monday, the United Nations Intergovernmental Panel on Climate Change released a harrowing assessment of the planet’s present and future climate. It says weather extremes will intensify as global warming continues, and many changes to ice sheets and sea levels will be irreversible for centuries to come. For the polar regions, the report’s findings are especially stark.