The Earth’s land has warmed by 1.5 degrees celsius over the past 250 years and “humans are almost entirely the cause”, according to a scientific study set up to address climate change sceptics’ concerns about whether human-induced global warming is occurring.
Prof Richard Muller, a physicist and climate change sceptic who founded the Berkeley Earth Surface Temperature project, said he was surprised by the findings. “We were not expecting this, but as scientists it is our duty to let the evidence change our minds.”
He now considered himself a “converted sceptic”. “It appears likely that essentially all of this increase results from the human emission of greenhouse gases,” Prof Muller wrote in the New York Times.
The team of scientists based at the University of California, Berkeley, merged 14.4 million land temperature observations from 44,455 sites dating back to 1753. Previous data sets only went back to the mid-1800s and used a fifth as many records.
The temperature data from various sources was not homogenised by hand – a key criticism by climate sceptics. Instead, the statistical analysis was “automated to reduce human bias”. _ (Guardian service)