Update: How Do You Tell If The Earth's Climate System "Is Warming"?
/Back in August I had a post by the title of “How Do You Tell If The Earth’s Climate System “Is Warming”? The post took note of the fact that, with a time series (like for temperature) that fluctuates up and down, you can always give a presentation that makes the trend look to be whatever you want it to be, so long as you get to pick the start date. If you want to make it look like the trend is up, you pick a start date where the value of the series is low; and if you want to make it look like the trend is down, you pick a start date where the value of the series is high. Nothing to it! With the earth’s climate system, you have nearly infinite numbers of years that you can go back to get the result you want. Those who want to convince you that the earth’s climate system “is warming” typically pick as their start date either the 1880s or the 1970s, both of which were notable low points in the temperature times series. The trick is so obvious that you would think that nobody could be fooled. But, among others, they seem to have bamboozled Google, which as that August post noted, had taken to including on YouTube videos involving climate skeptics a legend stating “Multiple lines of scientific evidence show that the climate system is warming.”
“Multiple lines of evidence”? Really Google, is there any “line of evidence” that matters as to whether something “is warming” or “is cooling” other than the temperature time series? They don’t enlighten us as to what that other “line of evidence” might be.
Anyway, enough months have now passed for another year to end, so we now have three full years since the most recent temperature peak, which occurred in January 2016. . . .
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