A slowing in global warming that climate sceptics say undermines the greenhouse theory is simply a “hiatus” from higher temperatures, scientists said on Wednesday. Grasping one of the thorniest issues in climate politics, the researchers said the recent slowdown lies in a natural but temporary cooling in the tropical Pacific Ocean.
“The current hiatus is part of natural climate variability,” they said. Similar events may occur again, but when assessed on a timescale of decades, “(the) warming trend is very likely to continue with greenhouse-gas increase,” they said.
The question touches on an anomaly in climate science.Contrary to earlier predictions, warming of Earth’s surface in recent years has not occurred in lock-step with rising levels of heat-trapping gas in the atmosphere. Over the last 50 years, temperatures have risen by an average of 0.12 degrees Celsius (0.21 degrees Fahrenheit) per decade. But over the last 15 years, the increase has slowed to a rate of 0.05 C (0.09 F) per decade, even though fossil-fuel carbon emissions continue to break new records.
Skeptics have seized on the discrepancy as proof that if warming exists, it is not man-made but has natural causes such as fluctuations in solar heat.The new study, published in the journal Nature, uses a climate model—and not observed data, which is generally considered stronger—to say the riddle is explained by ocean circulation. Via Slowdown in global warming only temporary, new study finds.