Is Geography Behind Sea-Ice Paradox?
Is Geography Behind Sea-Ice Paradox?
When sea ice covering the Arctic Ocean fell to a record-low level last month, much of the analysis in Asia and the Pacific focused on the opening of new and shorter commercial shipping routes to Europe, and increased access to Arctic offshore oil and gas resources.
These could be very positive developments for the region, especially for the energy-short trading economies of Northeast Asia led by Japan, China and South Korea.
But the dramatic decline in both the extent of Arctic sea ice and its thickness since the start of reliable satellite measurements in 1979 may also signal an alarming acceleration in global warming and climate change caused mainly by burning fossil fuels and clearing forests.
Sea ice is an extensive layer of frozen ocean water that cools the polar zones — the Arctic in the Northern Hemisphere and Antarctica in the Southern Hemisphere. It also helps to moderate the global climate.
Sea ice has a bright surface. As a result, about 80 percent of the sunlight that strikes it is reflected back into space. However, as sea ice melts in the summer, it exposes the dark ocean surface that then absorbs approximately 90 percent of the sunlight. The ocean warms and Arctic temperatures rise further.
Yet there is a seeming paradox between what is happening to sea ice in the Arctic, where it is shrinking fast, and Antarctica, where it has been expanding steadily in recent years.