Mountains of Evidence
While the evidence supporting global warming is plentiful, those looking to deny it have had very few fact-based arguments in their arsenal. One of those arguments has been an apparent slowdown in the increase of ocean temperatures during a period around the turn of the century, from 1998 to 2012, which has become known as the "global warming hiatus."
Though the reason behind the phenomenon was unclear, this hiatus was generally accepted by the scientific community. Then, in 2015, researchers from the National Oceanic and Atmospheric Administration (NOAA) published a controversial paper in the journal Science that made sense of the slowdown by proving that it never actually happened. They proposed that the tools used to measure the surface temperature in the decades before the hiatus actually delivered warmer readings than modern tools, giving the false impression of decreased rates of warming.
After they corrected for this "cold bias," the NOAA researchers concluded in their 2015 study that ocean temperatures had risen 0.12 degrees Celsius (0.22 degrees Fahrenheit) each decade since 2000, almost double the previously estimated 0.07 degrees Celsius (.13 degrees Fahrenheit). These revised figures are in line with the rate of increase seen in the three decades prior.
Now, a team of researchers from the University of California, Berkeley, and Berkeley Earth, a non-profit research institute focused on climate change, has confirmed that controversial paper. They've published their findings in the journal Science Advances.
Those researchers looked at independent data from a combination of satellites, robotic floats, and ocean buoys to test NOAA's claims. By looking at just one type of data at a time, rather than trying to make judgment calls based on readings from a variety of instruments, they were able to get several unbiased data sets, and each set — whether from just the buoys, just the satellites, or just the floats — confirmed NOAA's findings.
"Our results mean that essentially NOAA got it right, that they were not cooking the books," said lead author Zeke Hausfather, a graduate student in UC Berkeley's Energy and Resources Group.
No Relief in Sight
In the debate over climate change, the slightest hint of evidence that global warming isn't happening or that researchers are skewing data can be used by deniers as an argument against the entire problem, muddling the issue and preventing action. This independent confirmation of NOAA's study disproving the hiatus helps shore up one perceived point of weaknesses in the mountain of evidence that manmade climate change is real.
"In the grand scheme of things, the main implication of our study is on the hiatus, which many people have focused on, claiming that global warming has slowed greatly or even stopped," Hausfather said. "Based on our analysis, a good portion of that apparent slowdown in warming was due to biases in the ship records."
With this good news comes bad: climate change isn't slowing down. Species are on the brink of extinction, and one global superpower may soon take a major step back in the fight against global warming. Thankfully, other governments, organizations, and individuals are stepping up to develop clean-energy alternatives to the fossil fuels at the core of this worldwide problem.