Earth warming faster than expected: study
The world’s oceans have been soaking up far more excess heat in recent decades than scientists realized, suggesting that Earth could be set to warm even faster than predicted in the years ahead, according to new research published Wednesday.
Over the past quarter century, the Earth’s oceans have retained 60 per cent more heat each year than scientists previously had thought, said Laure Resplandy, a geoscientist at Princeton University who led the startling study published Wednesday in the journal Nature. The difference represents an enormous amount of additional energy, originating from the sun and trapped by the Earth’s atmosphere — more than eight times the world’s en- ergy consumption, year after year.
In the scientific realm, the new findings help to resolve long-running doubts about the rate of the warming of the oceans prior to 2007, when reliable measurements from devices called “Argo floats” were put to use worldwide. Before that, different types of temperature records — and an overall lack of them — contributed to murkiness about how quickly the oceans were heating up.
The higher-than-expected amount of heat in the oceans means more heat is being retained within the Earth’s climate system each year, rather than escaping into space. In essence, more heat in the oceans signals that global warming itself is more advanced than scientists thought.
“We thought that we got away with not a lot of warming in both the ocean and the atmosphere for the amount of CO2 that we emitted,” said Resplandy, who published the work with experts from the Scripps Institution of Oceanography and several other institutions in the U.S., China, France, and Germany. “But we were wrong. The planet warmed more than we thought. It was hidden from us just because we didn’t sample it right. But it was there. It was in the ocean already.”
Wednesday’s study also could have important policy implications. If ocean temperatures are rising more rapidly than previously calculated, that could leave nations even less time to dramatically cut the world’s emissions of carbon dioxide, in hopes of limiting global warming to the ambitious goal of1.5 C above pre-industrial levels. The world already has warmed 1 Celsius since the late 19th century. Scientists backed by the United Nations reported earlier this month that with warming projected to steadily increase, the world faces a daunting challenge in trying to limit that warming to only another half degree Celsius. The group found that it would take “unprecedented” action by leaders across the globe over the coming decade to even have a shot at that goal. The new research underscores the potential consequences of global inaction. Faster warming oceans mean that seas will rise faster and that more heat will be delivered to critical locations that already are facing the effects of a warming climate, such as coral reefs in the tropics and the ice sheets of Greenland and Antarctica.