University of Washington climatologist Cecilia Bitz is another Arctic amplification scholar not involved in the study. Blitz points out that there has been a delay in how high-latitude areas have reacted to greenhouse gases relative to the rest of the planet. The melting of sea ice took time, but now that it is happening, Arctic heat levels have soared and the change has become much more evident. “The tropics warmed up earlier, and now the poles are catching up, and it’s an obvious trend“, says the researcher.
The consequences are already enormous. First, a major dissolution – especially in Greenlandwhich is losing about 250 billion tons of ice per year – implies a sea level rise. Additionally, warmer waters become physically larger, a phenomenon known as thermal expansionfurther raising the sea level.
The landscape is also undergoing an upheaval. Rising temperatures are thawing frozen ground, known as permafrost. When the permafrost it loses water, collapses, dragging critical infrastructures with it, such as gas pipelines, roads and buildings. “The inhabitants of the Arctic – observes Bitz – they did nothing to deserve to live in such a dangerous environment“.
The rise in temperatures also stands greening the territory. Shrub species are moving north and vegetation traps more snow on the ground. This prevents the cold of winter from penetrating, potentially speeding up the thawing of the permafrost. All of this extra vegetation is also darker – just like the sea is darker than ice – and therefore absorbs a greater amount of solar radiation.
In practice, the Arctic is sinking intoclimatic and ecological uncertainty. “Every summer I go with my field research team and never really know what to expect – admits Isla Myers-Smith, an ecologist studying global change at the University of Edinburgh, not included in the study. This year we arrived in Inuvik, Canada, where a heat dome reached temperatures of 32 degrees, but there was still a lot of sea ice on the coast, which mitigated temperatures locally.“.
This variability makes it difficult to model Arctic change and predict how these will affect the climate system more generally. This is why it is so It’s important that scientists review their knowledge and realize that the Arctic is actually warming four times faster compared to the rest of the planet.
A major concern is the possibility of the climate system reaching a tipping point where warming would trigger rapid change. If the Arctic warms up sufficiently, for example, the melting of Greenland can accelerate dramatically. “We are not sure – in case these critical points really exist – what is the level of warming capable of triggering such sudden changes“says Michael Previdi, a climate scientist at Columbia University’s Lamont-Doherty Observatory, not included in the study. And he goes on to hypothesize that in theory a larger amplification factor could.”increase the chances of reaching one of these critical points“.