As average global temperatures have increased by around 1C since the start of the industrial era, the Arctic has become one of the most rapidly warming regions on Earth. Previous reports revealed that the region has seen around twice 1C of warming. In some parts of the Arctic, the temperature rise is four times higher than the global average. A 2016 study calculated that for every ton of carbon dioxide emitted into the atmosphere, summer sea ice in the region shrinks by three square meters.
Arctic amplification, the phenomenon of the Arctic heating up at a faster rate than the rest of the globe, happens for a variety of reasons. According to Carbon Brief, a UK-based website designed to improve the understanding of climate change, both in terms of the science and the policy response, the researchers suggest that it is closely related to interactions between the atmosphere, sea ice, and ocean. One of the examples is the “ice-albedo feedback,” one of the most well-known of the feedback loops that impact the rate of Arctic sea ice melt.
Dr. Michel Tsamados, a sea ice researcher from University College London, explained that this interaction happens when climate change brings more heat to the Arctic’s atmosphere and ocean, causing sea ice to melt more rapidly. Since satellite records began in 1979, summer Arctic ice has lost 40% of its area and up to 70% of its volume. In 2019, it shrank to its second-lowest extent on record. Scientists fear that the worsening impacts of global warming and the increasing carbon emissions will result in ice-free Arctic summers.
All Ice in the Arctic May Be Gone
Several recent reports revealed the accelerated loss of summer sea-ice cover in the Arctic. What makes this more alarming is that the observed ice loss is generally happening faster than climate models have forecasted. Historically, the Arctic Ocean was covered by ice year-round, but today this area is about half of what it used to be. Studies have blamed greenhouse gases as the primary driver of the long-term decline of the summer ice cover.
If this continues, scientists predict that the Arctic Ocean in summer will most likely be ice-free before 2050. While the area of the sea ice cover in the North Pole decreases, the overall area of the Arctic Ocean that is covered by sea ice has rapidly been reduced over the past few decades. The researchers said that how often the Arctic will lose its sea-ice cover in the future critically depends on the future of carbon emissions.
"If we reduce global emissions rapidly and substantially, and thus keep global warming below 2 °C relative to preindustrial levels, Arctic sea ice will nevertheless likely disappear occasionally in summer even before 2050. This really surprised us,” Dirk Notz, who leads the sea-ice research group at the University of Hamburg, Germany, said.
According to Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, the researchers used 40 different climate models to examine the future evolution of Arctic sea-ice cover in a scenario with high future carbon emissions and little climate protection. The results of these simulations revealed that the Arctic sea ice disappeared quickly in summer. The team used simulations based on so-called SSP Scenarios which will also be used for the next IPCC report. Scenarios SSP1-1.9 and SSP1-2.6 are used to simulate a rapid reduction of future CO2 emissions, while scenario SSP5-8.5 is used to simulate largely unchanged future CO2 emissions.
Ed Blockley, who leads the UK Met Office’s polar climate programme and was one of those behind the new research, said that the models repeatedly show the potential for ice-free summers in the Arctic Ocean before 2050. The findings of the study published in the journal Geophysical Research Letters showed that the Arctic Ocean will only be considered ice-free when it shrinks to fragments with a combined area below 1m sq km, which is 75% lower than in 2019.
While the models are not perfect and struggle to match closely the ice loss and global warming seen in historical data, Blockey said that all models show that the sea ice will continue to decline. According to The Guardian, a British daily newspaper, another alarming result revealed that the ice-free Arctic in the winter months appears possible if carbon dioxide continues to be emitted at high levels. “That’s not something we’ve seen before in these projections. A winter ice-free event would be catastrophic, for some wildlife species [like polar bears] for example, that live and hunt around the sea ice,” Blockley said.
Setting a Date
The researchers have already clarified that their models may not be accurate. However, the overall prediction of a soon-to-be ice-free Arctic is highly possible. According to Science Alert, a leading scientific publisher dedicated to publishing peer-reviewed significant research work, delivering quality content, scientists have been forecasting this outcome for years and speculating what this could mean for all kinds of other ecosystems. These outcomes would also amplify the global warming effects the world is currently experiencing.
Scientists explained that with less ice in the Arctic, less sunlight can be reflected in the region, meaning our already hotter planet absorbs even more heat as the North Pole increasingly melts away. "It's a two-way street. The warming means less ice is going to form and more ice is going to melt, but also, because there's less ice, less of the Sun's incident solar radiation is reflected off, and this contributes to the warming,” NASA climate scientist Claire Parkinson said.
Researchers find it difficult to know when the Arctic will have its first ice-free summer. Different climate models come up with a wide range of possible dates, spanning 2005 to after 2100. However, the majority of climate models suggest that it is likely to happen sometime around the middle of the century. A 2016 study revealed that the Arctic could see its first ice-free summer as early as 2032 if humans make very little effort to cut global emissions.
“There’s still a big range and it depends on the model that you’re looking at. But, basically, what all the models show is that, at some point, summer sea ice will be lost,” Dr. Thomas Rackow, a climate modeler from Alfred Wegener Institute (AWI), said.