Using new data, US finds no pause in global warming

Using updated data on the Earth's surface temperatures worldwide, US government scientists have found no evidence of a pause in global warming in recent years, according to research published on Thursday.

The report by scientists at the National Oceanic and Atmospheric Administration (NOAA) was published in the journal Science.

It had been thought that temperatures in the 21st century plateaued.

"The new analysis suggests no discernible decrease in the rate of warming between the second half of the 20th century, a period marked by manmade warming, and the first fifteen years of the 21st century, a period dubbed a global warming 'hiatus,'" the report said.

The study uses "updated and corrected temperature observations taken at thousands of weather observing stations over land and as many commercial ships and buoys at sea," it said.

With that data, there is no evidence that temperatures in the 21st century have in fact plateaued.

"Instead, the rate of warming during the first fifteen years of the 21st century is at least as great as that in the last half of the 20th century, suggesting warming is continuing apace," said the study.

Rising temperatures across the planet have set new records, and NOAA has declared 2014 was the hottest year in modern history.

The globe experienced its hottest month of March since record-keeping began in 1880, and the period of January to March was also the warmest on record, NOAA has said.

Scientists warn that fossil fuel burning is pushing more greenhouse gas into the atmosphere, leading to increased temperatures, melting of polar ice and glaciers and rising seas.

Experts said the latest study should address some key uncertainties in global warming projections, which are at the heart of major world climate talks in Paris later this year.

"A whole cottage industry has been built by climate skeptics on the false premise that there is currently a hiatus in global warming," said Mark Maslin, professor of climatology at University College London.

"This important reanalysis suggests there never was a global warming hiatus; if anything, temperatures are warming faster in the last 15 years than in the last 65 years."

Some experts hailed the Science article for using better quality data than the figures used to create the Intergovernmental Panel on Climate Change's 2013 report, which found some evidence of a pause in global warming in recent years.

But others, like Piers Forster, professor of climate change at the University of Leeds, pointed out that the IPCC report relies on numerous sets of data, not just NOAA's.

"Even with the corrections in this study, the observed warming has not been as large as predicted by models. Other global datasets, even when corrected for missing Arctic data, still show a decreased trend since 1998," he said.

"I still don't think this study will be the last word on this complex subject."

AFP

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