Evidence the earth experienced a slowdown in global warming over the past couple of decades has been further eroded with a new US study confirming climate change continues unabated.
Subscribe now for unlimited access.
or signup to continue reading
Eighteen months ago, the US National Oceanic and Atmospheric Administration (NOAA) sparked wide-ranging debate with its report finding recent ocean warming had been underestimated because of a cooling bias contained in the way data was collected, particularly from ships.
Correcting for this bias – largely from the use of less accurate ship-based estimates – NOAA found the oceans had warmed at the rate of 0.12 degrees per decade since 2000, or nearly twice the previous estimate.
The correction brought the period into line with warming over the previous 30 years and undermined claims, particularly from groups sceptical that humans are driving climate change, of a "warming hiatus" despite rising carbon emissions.
The new study – published in Science Advances journal by researchers at the Berkeley Earth, a non-profit organisation and the University of California, Berkeley – replicated the NOAA findings.
It analysed separately data from satellites, buoys and robots and found each matched NOAA's revision.
"Our data firmly closes that chapter – we were actually underestimating the warming," Zeke Hausfather, a researcher at Berkeley Earth. "It shows [NOAA] weren't cooking the books, they weren't manipulating the data to get results that were favoured by the [Obama] administration. It's hard to find any way to say there's been a slowdown any more."
The paper comes at a sensitive time in the US with many of the proposed appointments in the incoming Trump administration disputing climate change is real. The Trump transition team even demanded a list of all employees in the Energy Department who had attended climate meetings before threat of lawsuits prompted a withdrawal of the order.
US scientists fear a repeat – or worse – of the administration of George W. Bush when reports were doctored to remove political implications of the climate research. Even during the Obama years, the Republican-controlled Congress launched three investigations into NOAA that failed to find fault, Mr Hausfather said.
"The way science works is through replication not political investigation," he said. "If you disagree with someone's published results, you should look at other data sets and redo their analysis like we did, rather than asking for [scientists'] emails," he said.
Such probes would not affect the science nor the warming itself, but made it harder for scientists to do their research amid a flood of freedom of information requests and served to discourage others from entering the field, Mr Hausfather said.
It's expected that 2016 will make it three years in a row of record temperatures, aided in part by a strong El Nino in 2015-16. The British Met Office predicts only a modest pullback this year.
Mr Hausfather said scientists take a longer view than annual variability to assess warming.
"It may be four to five years to have another hotter year [than 2016] but 14 of the last 15 years are the warmest of record," he said.
