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Originally Posted by Biochemist
I am asking for the FOURTH time to see if you can extrapolate your model to the time period 1998-2008, or explain WHY this question is somehow inapplicable!!!!!
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I've answered your question already. Would you like me to perhaps address your question using a different model, because that would be applicable.
And, out of curiosity... What exactly do we gain by arbitrarily adjusting the endpoints of our graphs to start at 1998? Is it perchance that 1998 was one of the hottest years on record, and you want to show that... relative to that very warm year... the temperature hasn't risen dramatically since then?
It's important to know why you wish me to arbitrarily choose a different maximum on such a short time scale. I sense academic dishonesty coming, which is why I've been pushing back on you so hard. If you are truly interested in furthering knowledge, then be clear why you are making your request, or better yet, offer your own data to support the postion you are arguing (per site rules).
I assume you are going to suggest that 1998 was "the last year to warm," another argument already debunked:
It hasn't warmed since 1998
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1998 was an unusually hot year as it featured the strongest El Nino of the century. In fact, from Jan to May, 2007 is tied with 1998 as hottest year on record. The WMO reported in August that January and April 2007 were the hottest on record.
However, when determining trends, you don't pick one month or year out of isolation - particularly if that year features a short term weather anomaly like El Nino. By this method, based on the fact that 2005 was .17°C hotter than 2000, you could conclude that the rate of global warming doubled from 2000 to 2005.
5 year moving average
When considering long term climate trends, you need to filter out short term weather anomalies like El Nino or volcanic eruptions - an easy way is to plot a 5 year average. This shows the trend hasn't reversed at all.
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Line of best fit
While a 5 year average is visually compelling, a more rigorous statistical method to determine any trend is to apply a line of best fit to the data.
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In this case, a line of best fit calculates the temperature trend is 0.16°C per decade from 1998 until July 2007. This is a close match to the temperature trend over the last 30 years (0.15°C from 1975 to 2007). So even starting from 1998, we find the planet is still warming at the same rate.
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Emphasis mine.
Data @ NASA GISS: GISS Surface Temperature Analysis: 2005 Summation
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Recent warming coincides with rapid growth of human-made greenhouse gases. Climate models show that the rate of warming is consistent with expectations.
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Originally Posted by Biochemist
So, my question (again, based on my unmatchable ignorance) is how does the "model" explain the "observed" data for the temperature plateau period 1998 through 2008?
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Also, as I've now shown, your use of the word plateau is an invalid linguistic representation of the temperature observations being made.
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