In climate-change news, scientists have found that the world’s oceans are heating up to 40 per cent faster on average than the estimates of a 2014 United Nations panel report. This research from four different studies was published in the journal Science. The researchers also found that ocean temperatures have been rising significantly since 1991 and broken records for several years.
Previous studies underestimated the magnitude of this temperature rise but with Argo, which is a satellite-linked global system of ocean temperature-measuring devices, researchers have been able to take better measurements. Argo is a network of drifting floats that measure the temperature and saltiness of the upper 6,500 feet of the oceans. This new system has allowed scientists to accurately measure historical warming for several parts of the oceans. This was the main reason why previous research found the rate of warming to be lower.
Between 1991 and 2010, the ocean warmed more than five times faster on average, than in the 1971 to 1990 period. This warming has contributed to ‘increases in rainfall intensity, rising sea levels, the destruction of coral reefs, declining ocean oxygen levels, and declines in ice sheets, glaciers, and ice caps in the polar regions’ as per this report.
Oceans absorb and store most of the excess heat produced by the planet. This is because it takes more energy to heat up water than air and water also holds on to that energy far more effectively than air. While this has helped slow down the effects of global warming, ocean temperatures are rising steadily resulting in dire consequences for marine life, food security, and coastal populations as sea levels are expected to rise higher and cyclones will get more powerful and destructive. Most of the sea-level rise to date is because of this warming effect, and not melting ice caps, although the latter is bound to contribute significantly to catastrophic rises in the near future.
Oceans contain 93 per cent of the extra heat in the form of greenhouse-gas emission. Even with current efforts to cut our emissions, oceans will be warming the atmosphere for centuries to come. What this essentially means is that, barring some technological miracle, there is no going back on the damage that has been done to the oceans and the planet.