Global warming 'pause' does not exist, researchers say

Global warming has not slowed since the beginning of this century, researchers say, backing up a study from 2015 which was met with hostility by the US government.

Most scientists accept the idea the rate of global warming has "paused" over the last two decades.

However, a 2015 report by the US National Oceanic and Atmospheric Administration (NOAA) claimed researchers had underestimated sea temperatures in the past two decades and so falsely concluded that the rate of climate change had slowed, the BBC reports.

The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

In the 1990s, most data about ocean temperatures came from ships, where water was drawn in through engines and recorded. This has since changed and the information now comes from ocean buoys, which are more consistent and accurate.

NOAA argued that the buoys tend to report cooler temperatures – which makes sense, says the Washington Post, given that ship engines are relatively warm places.

Reworking historical figures to take this "cold bias" into account, the organisation concluded that oceans have warmed 0.12C per decade since 2000 - almost twice as fast as the previous estimates of 0.7C.

NOAA's findings so angered climate-change sceptics that the authors' emails were subpoenaed by the House of Representatives.

Lamar Smith, chairman of the House committee on science, asked for the information on why the scientists had made the "cold bias" as well as their communications among themselves.

But NOAA's work has now been supported by fresh analysis published in the journal Science Advances, which replicates the findings.

With the revised data, there is no apparent pause in global-warming growth between 1998 and 2014.

"We pretty robustly showed that NOAA got it right. There was no cooking of the books, there's no politically motivated twisting of the data," said lead researcher Zeke Hausfather of the University of California-Berkeley.

"It's impossible to differentiate the rate of warming over the last 18 years from the longer term rate of warming over the last 30 or 50 years… I don't think we can say any more that we have evidence that global warming has slowed down in any way."