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Showing posts with the label arctic sea ice

Responding to the CO2 Coalition's "Fact #15" on Eemian Warmth

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CO2 Coalition 's " Fact #15 " wants us to believe that temperatures even 8°C warmer than today would be just fine for humanity. In order to make that claim, they need to perform a few tricks. The first trick is to make that 8°C Greenland temperatures instead of global temperatures. The second trick is to redefine  "today" as "the mean of the past millennium." Here's how they say it The results revealed that the Eemian interglacial warm period, between 130,000 and 115,000 years ago, was much warmer than previously thought. In fact, it was, 8°C (14.4°F) warmer than today. Their source for this is Dahl-Jensen 2013[1], which details the results of the new North Greenland Eemian (NEEM) Ice Drilling ice core. The paper concludes: NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer i

Tony Heller on Arctic Sea Ice

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I wonder if there's a climate conspiracy that isn't found on Tony Heller's blog in some way, shape or form. We have plenty of empirical data showing the decline in Arctic Sea Ice, but according to Tony Heller, that's not the case, and NOAA is actively hiding data that would prove them wrong. According to him, we have satellite data going back to 1972, but NOAA only shows data beginning in 1979 because that was a cold year, and if they showed the 1972 -1978 data, it would undermine their claim that Arctic Sea Ice is shrinking. "The reason why NOAA starts their sea ice graphs in 1979, is because it was the coldest year on record in much of the Arctic and the ice was very thick. By starting in 1979, they can defraud the public into believing that the ice is disappearing."[1] But Heller apparently did some sleuthing and found that data in a 1990 IPCC report so he can alert the world to the data that NOAA is hiding away. But is this data hidden? Well, no. It's

How Should we Understand Confidence Intervals?

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This is Wrong Whenever you read the scientific literature, you'll frequently encounter estimates that include "confidence intervals." Generally speaking most of us understand these to give us an understanding of how sure scientists are that in their estimates they "got it right." And yet there is frequently confusion and even miscommunication about what confidence intervals mean that can sometimes unintentionally cause us to misrepresent (even if slightly) what scientists are actually claiming. It's something I've done in the past, and it's something that affects many well-intentioned people just trying to represent the data accurately. What I want to do in this post is to accurately describe what is being stated when confidence intervals (CIs) are reported, and then offer some reflections on the way this can impact our communication of the confidence we can have in scientific evidence. Confidence vs Probability At the heart of the confusion is a fai