- justa-hairyape
The graph does not attempt to suggest that warming (or cooling) was "stepped", the point of that presentation is that you cannot legitimately conclude anything about longer-term trends from decade-long shorter term temperatures; for example you could easily cherry pick portions of the same data set to construct a similar "demonstration" that the temperature record consisted of a series of decade-long warming periods.
This was exactly Curry's complaint in the article linked above about some comments on the BEST analysis (or any such analysis); based on the last ten or fifteen years of data you can not demonstrate with reasonable confidence that warming has stopped or that it has continued, in fact you cannot anything at all about long-term climate trends from less than around thirty years of data.
And this is always the case (on a purely statistical basis) about the last thirty years of data.
(Of course, if things change radically - if the snow on the ground in Chicago does not melt in June three years in a row, or ocean circulation patterns suddenly change and adjacent land masses average 3F warmer three years in a row, - then all bets are off, and you can reasonably conclude the novel factors are affecting climate over very short time-frames).
And if the last twenty or thirty years or data cannot inform our judgement of longer-term trends with statistical confidence, how can we proceed?
Our best method is to look back over longer time periods, attempt to determine the causes of climate changes during those periods, and extrapolate forwards, the logic goes:
1) We know that over the last hundred years or so, average global temperatures have been rising.
2) Based on our understanding of atmospheric physics and chemistry, we can provide a reasonable explanation of how human activity could have caused much or all of this longer term trend.
(3) This activity is continuing (in fact, its accelerating).
(4) Therefore, it is reasonable to conclude (though we cannot demonstrate it on the basis of shorter-term data) that the longer-term warming trend is continuing.
Statistically, no one can do any better, you cannot discern anything meaningful about changes in the long-term trend from the shorter term data, and it's a complete waste of time to argue over what the short-term demonstrates about the longer term trends, because it does not demonstrate anything.
So when you read someone going on about how "the earth has been cooling for the last decade" or "last(whatever it is) month is the warmest in the last (whatever it is) years", blah, blah, blah... ignore that part of the argument, it's just "noise".
Instead, concentrate on the debates about underlying causes of the longer term trend, that's were the action is.
If you cannot step 10 years to determine a 30 year trend, how can you step 30 years for a 100 year trend? And what does a 100 year trend mean for a planet that has seen climate change over 100,000 year periods? How can you step 100 years to determine a 1000 year trend?
And what would make anyone think we know the average temperature of the entire earth for the year 1812? Or 1513? To within 1-2 degrees? That is hubris.
Okay. Now you’re doubling down on wrong.
The “thing” with the last ten years is not that it has stayed constant. A few internet posters might make that claim but they misunderstand. Refuting a misunderstanding of the original point is not proving the original point.
The thing is that it has stayed constant DESPITE all the corrections to explain constant periods in the past. Either the warmists have to come up with a new correction for the past ten years or they have to admit that their models are fundamentally incorrect.
Get a plot of the divergence of the model predictions from the Berkley data and and you’ll see that the models have not predicted the temperature trends. If they don’t have the right physics to predict the trends over the past ten years then they cannot predict the trend for the next ten years.
Whatever. Warming has stopped or we are now cooling for at least 10 years. You cannot hide that fact with long term trends. That is what is interesting. Why has the cooling in the warming trend occurred when CO2 levels have increased ? That blows the whole CO2 is gonna kill us meme to shreds.
(Of course, if things change radically - if the snow on the ground in Chicago does not melt in June three years in a row,....
That is what you will need to recognize that recent cooling has occurred ? By the time snow does not melt in June in Chicago, millions will have died from cold weather all across the planet. You wont need to look at Chicago. Just watch how many animals die in Mongolia this winter. Assuming of course that they still have a significant number left after the previous 3 winters.
...how can we proceed?
Stop wasting billions on cooling a planet that may already be cooling. What they are doing may end up being counter productive.
1) We know that over the last hundred years or so, average global temperatures have been rising.
And according to BEST we have risen 2.5 C in the past ~ 200 years, yet we are all still doing fine. So why would another 2 C kill many of us ?
2) Based on our understanding of atmospheric physics and chemistry, we can provide a reasonable explanation of how human activity could have caused much or all of this longer term trend.
According to BEST we rose about 1.5 C from about 1813 to about 1875. So what human activity caused that ? Steam locomotives ?
(3) This activity is continuing (in fact, its accelerating).
False. It cannot be considered to be accelerating when BEST says it has stopped for 10 years. And we experienced a 1.5 C rise from 1813 to 1875 while we only rose 1.5 C from 1875 to 2010. Note - Dates are approximate.
(4) Therefore, it is reasonable to conclude (though we cannot demonstrate it on the basis of shorter-term data) that the longer-term warming trend is continuing.
False. It is reasonable to conclude that the long term trend has been temporarily halted. The real question is why and all the dancing about the long term trends gives no possible answer. In fact, it just obfuscates the science, which is the only tool the AGW acolytes possess right now.
Statistically, no one can do any better, you cannot discern anything meaningful about changes in the long-term trend from the shorter term data, and it's a complete waste of time to argue over what the short-term demonstrates about the longer term trends, because it does not demonstrate anything.
Actually, the short term data is extremely important if we have moved into a cooling cycle. Only the short term data will give you a clue. As a scientist, you must explain the short term trend. And please, blame the apes last, not first.
...blah, blah, blah... ignore that part of the argument, it's just "noise".
It is not noise. It is going to kill people and animals this winter in the NH. Especially those idiots that still think we are warming.
Instead, concentrate on the debates about underlying causes of the longer term trend, that's were the action is.
No. Absolutely not. You need to explain the now verified short term trend change. That is what we call science.