August 23, 2017 weblog
Research pair suggest global warming almost completely natural (Update)
Australian biologist and climate science denialist Jennifer Marohasy and computer scientist John Abbot have published a paper in the journal GeoResJ outlining their study of climate change using neural network technology—their results show that the climate changes the world is now experiencing are almost completely natural. Marohasy offers an additional explanation and outline of their work on her blog. Also, alt-right news site Breitbart offers a take on the work.
Most scientists around the world have reached a consensus on global warming—it is happening, and it is happening because humans have ejected so much CO2 into the atmosphere. But Marohasy and Abbot claim that this consensus is built on a faulty base, one decided upon almost a century ago, when work was done to learn about the heat absorption potential of carbon dioxide. They suggest further that so little work has been done since that time applying the principles globally that it is impossible to prove that carbon dioxide has the ability to impact world temperatures. For that reason, they began collecting data from prior studies that offered a means of temperature reading over the past 2000 years—tree rings, coral cores etc. They fed that data into a neural network that Abbot has been using to predict rainfall patterns in Australia for the past several years. The network functions by looking at patterns and learning about given situations—in this case, global temperature patterns over the course of 2000 years, and then offers predictions.
The researchers report that the computer predicted temperatures rising in roughly the same way as they have based on real-world measures—in the absence of added carbon dioxide—which suggests that carbon dioxide is not the cause. They also note that there was a time known as the Medieval Warm Period that ran from approximately 986 to 1234, when temperatures were roughly equal to those today. This, the two researchers suggest, offers evidence that the planet would have heated to the degree it has regardless of whether humans pumped carbon dioxide into the atmosphere for a hundred years or not. They note that their results also showed global temperature averages declining after 1980, which coincides with the slowdown noted by other mainstream scientists, but not fully explained. They suggest the warming we are now experiencing is mostly naturally occurring and that it will likely abate just as it has done in the past.
The research was funded by the B. Macfie Family Foundation. GeoResJ journal will be discontinued from January 2018 and is closed to new submissions.
More information: John Abbot et al. The application of machine learning for evaluating anthropogenic versus natural climate change, GeoResJ (2017). DOI: 10.1016/j.grj.2017.08.001
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