'Global warming not progressing as fast as depicted in worst-case models'

A new study shows natural variability in surface temperatures can account for observed changes in the recent rates of warming from decade to decade.

A new study has revealed that global warming is progressing at a moderate rate than the scenarios depicted in the worst-case models outlined by the Intergovernmental Panel on Climate Change (IPCC).

A new study based on 1,000 years of temperature records suggests global warming is not progressing as fast as it would under the most severe emissions scenarios outlined by IPCC.

The study led by Duke University showed that natural variability in surface temperatures, caused by interactions between the ocean and atmosphere, and other natural factors, can account for observed changes in the recent rates of warming from decade to decade.

The researchers say these "climate wiggles" could slow or speed the rate of warming from decade to decade, and accentuate or offset the effects of increases in greenhouse gas concentrations. If not properly explained and accounted for, they may skew the reliability of climate models and lead to over-interpretation of short-term temperature trends.

The research used empirical data, rather than the more commonly used climate models, to estimate decade-to-decade variability.

Patrick T Brown, a doctoral student in climatology at Duke University's Nicholas School of the Environment said Statistically, it's pretty unlikely that an 11-year hiatus in warming, like the one it was seen at the start of this century, would occur if the underlying human-caused warming was progressing at a rate as fast as the most severe IPCC projections.

Hiatus periods of 11 years or longer are more likely to occur under a middle-of-the-road scenario, he further added.

The study is published in the peer-reviewed journal Scientific Reports.