Environment

Ice-Free Arctic Ocean in 2030?

Vast uncertainty remains over the causes of melting Arctic sea ice and when it may disappear altogether during the summer, which would have consequences for oil explorers, shipping firms and the fight against climate change.

The answer will depend on the balance of natural and manmade causes.

Last September sea ice reached its lowest level in the satellite record, which dates back to 1979, a development that has implications for local native communities and wildlife, local coastal erosion and possibly northern hemisphere weather.

Under the albedo effect, dry snow reflects more than 80 percent of solar radiation; bare ice 65 percent; and open water just 5 percent.

And increasing expanse of open water each summer warms up faster than ice-covered sea, meaning new ice will be thinner and more vulnerable the following year.

There are various underlying causes of the melt.

Rising greenhouse gas emissions drive up air and sea temperatures.

Water from a warmer Atlantic entering the Arctic Ocean through the Fram Strait between eastern Greenland and Svalbard, an island due north of Norway.

A similar inflow of warmer Pacific water through the Bering Strait has long been identified as an important process that causes the thinning of ice in the central Arctic.

There are also weather effects that may be natural, partly natural or entirely due to greenhouse gas emissions affecting Arctic ice.

A particular weather pattern contributed to a big melt six years ago by sending warm air towards the central Arctic, according to researchers from the Netherlands, Sweden and Germany.

The cumulative impact from rising greenhouse gas emissions, which combined with a few freak summers, ice export and the albedo effect could finish off summer sea ice rather quickly.

Increasingly, scientists and researchers are coming to believe that a seasonally ice-free Arctic Ocean might be realized as early as 2030.