[QUOTE=ClimateGuy]
The recent warming cycle began 10,000 to 12,000 years ago at the end of the last ice age. Canada, Europe and the northern US were covered by glaciers. Since the beginning of the recent warming cycle the global temperature has risen about 8C. Millions of cubic miles of glaciers have melted. Man has flourished because of this. “Warm is better than cold” ~ Svente.
[/QUOTE]
And the climate was drastically different from what it is now. I wouldn’t want the climate to be even 1/8 different from what it is now versus the last ice age unless I were guaranteed it would be better, and contrary to your assertion, warmer is not necessarily better than colder. It could absolutely ruin the already marginal crops of billions of people, for one, and in a time frame orders of magnitude smaller than what the world experienced in the last ice age. Not to mention possibly messing up the gulf stream or decreasing shorelines where most of the worlds population lives at a time of huge human population, or destabilizing shoreline ecosystems due to them not being able to move inland fast enough due to never having experienced rising sealevels at this rate before…
awww, nevermind, I guess warm really will be better than cold.
[QUOTE=ClimateGuy]
The easiest way to look at this is to consider your body’s temperature. A normal temperature would be 98.6F. If your temperature rose to 99.2F it would be a temperature anomaly of +0.6F.
[/QUOTE]
How is the normal temperature for the earth determined?
[QUOTE=xenophon41]
And thus, until the first column maintains a moving average of “0”, the trend is a warming trend. A negative deviation from the most recent peak is significant only in comparison to temperature subsequent to previous peaks, not to the overall trend.
Just for giggles… Look at the “dip” in the moving average after the peak in 1877. Compare it to the shorter dip subsequent to the 1944 peak. Now, does the 1998 peak most closely resemble those peaks or is it closer to 1915 or 1926?
QC/QA people, does this process seem to be in control? If so, what does the chart predict if no corrective action is taken?
[/QUOTE]
You are looking at very small changes relative to “cooler” anomalies. The average anomaly since 1998 has been +0.23C, including 1998. This is hardly measurable let alone being labeled an acceleration. Particularly since the global temperature has risen 8C since the start of the current warming cycle.
Why choose this particular time frame? The OP gives us a hint by trying to explain it away in the final sentence. The 1997/1998 El Nino wasn’t any ordinary one, it was the strongest ever recorded - the degree of warming was unprecedented. 2006 was a mere blip that came along late in the season.
This is a standard GW denier tactic. It has been debunked so many times that they are now even acknowledging the problem with it, but try to write it off.
Google 1998 El Nino for hundreds of scientific reports confirming this.
[QUOTE=Lamar Mundane]
Why choose this particular time frame? The OP gives us a hint by trying to explain it away in the final sentence. The 1997/1998 El Nino wasn’t any ordinary one, it was the strongest ever recorded - the degree of warming was unprecedented. 2006 was a mere blip that came along late in the season.
This is a standard GW denier tactic. It has been debunked so many times that they are now even acknowledging the problem with it, but try to write it off.
Google 1998 El Nino for hundreds of scientific reports confirming this.
[/QUOTE]
Using the laws of conservation of energy how does El Nino generate heat to increase the global temperature?
[QUOTE=Larry Borgia]
How is the normal temperature for the earth determined?
[/QUOTE]
By taking an average over a period of time. Just like heating or cooling degree days balance points, it is somewhat arbitrary but does not detract from the relative changes in temperature.
You will hear that there was El Nino in 1998 causing the warmer temperatures. What you won’t hear is that there was also El Nino in 2006 causing the suppressed hurricane season, yet the global temperature anomaly was only +0.28C versus +0.50C in 1998.
[/quote]
First, why do you say, “What you won’t hear is…”? Do you think this information is somehow being suppressed?
Second, I think I’m missing the point you’re trying to make with the comparisons between the anomalies of 1998 and 2006? You’re not trying to say that the El Nino occurrence of 2006 was as strong as the 1998 occurrence, right? Why wouldn’t we expect the temperature anomaly to be greater with the latter?
What do you mean, “isn’t as good as other data”? And as for why the NCDC would continue to measure it, even if it weren’t: wouldn’t it be because it’s good to get as many data points as possible?
LilShieste
[QUOTE=ClimateGuy]
Using the laws of conservation of energy how does El Nino generate heat to increase the global temperature?
[/QUOTE]
I don’t read Lamar saying El Nino generated, as opposed to resulting from, heat, but in any case the Earth’s climate-and-biosphere are a non-closed endothermic system. See that big bright thing in the sky?
[QUOTE=ClimateGuy]
Correct. What are the analyses, where is the data and what is the source of the data?
[/QUOTE]
I’m citing your source. Your data.
Why are you presenting only the last 10 years of data, when the real data goes back much farther? Why is it necessary to prove your point to deliberately ignore 20 years of accumulated data?
What happens to your analysis if you include all known data from that source instead of picking out bits and pieces that support your conclusion?
Compare to Climate Guy’s very similar claims in this thread:
The arguments haven’t changed, as Lamar notes. The global temperature data over the last century show a significant and persistent (although not monotonic) increase, with a big-ass temperature spike due to the 1997/98 El Nino. The “No Global Warming Since 1998!” crowd is merely ignoring the overall trend in temperature in order to compare all recent temperature data to the 1998 spike alone.
This trick is so transparent that it amazes me that anybody still falls for it.
Why are you presenting only the last 10 years of data, when the real data goes back much farther? Why is it necessary to prove your point to deliberately ignore 20 years of accumulated data?
What happens to your analysis if you include all known data from that source instead of picking out bits and pieces that support your conclusion?
[/QUOTE]
Isn’t this akin to giving data for the stock market from 1999 to 2002 and saying, “Look! The stock market is practically crashing! How can people claim that the stock market has been going higher and higher ever since it opened?”
ClimateGuy, you raise an interesting but ultimately frustrating question. The problem with all claims about what has happened since say 1998 is the shortness of the dataset. When a dataset is that short (ten years), we simply don’t have enough information to say whether there is a statistically significant trend or not.
It’s not enough to see a trend. The question is whether a trend is statistically significant, that is to say, whether is it different enough from zero to be meaningful.
This lack of statistical significance is exacerbated by what is called “autocorrelation”, which is when a value is influenced by prior values. Autocorrelation is very common in temperature series (e.g., a hot July is likely to be followed by a hot August). The problem is that autocorrelated series often display what look like meaningful trends, but which on analysis turn out to be merely random variations due in part to the autocorrelated nature of the series.
With that as a prologue, we can look at the 1998 - 2007 series shown above. Is it statistically significant? The answer is no.
Is the lack of significance due to the El Nino peak in 1998? Again, no. We can determine this by replacing the 1998 value with the average of the two preceding and following years. When we do this, we find that the trend is still not statistically significant. In fact, there are no statistically significant trends in any ten-year period of the entire record.
Thus, the lack of a meaningful trend is not due to the 1998 El Nino, but instead is caused by a combination of the shortness and the autocorrelation of the temperature record. At this point, we can’t say much about the 1998-2007 record at all.
There is a more interesting anomaly in the cited temperature record, however. This is the fact that, while the land areas of the Northern Hemisphere have warmed 1979-2006, there has been no significant warming of the corresponding land areas of the Southern Hemisphere … I have never read any explanation of that fact.
[QUOTE=Kokopilau]
Isn’t this akin to giving data for the stock market from 1999 to 2002 and saying, “Look! The stock market is practically crashing! How can people claim that the stock market has been going higher and higher ever since it opened?”
[/QUOTE]
I think your quote is a very good encapsulation of why I’m curious about the OP’s rationale for excluding 66% of the available data on that site.
Yes, the recent relative trends are important — but if we’re at a global temperature right now where our ice caps are melting and our seas our rising, I don’t want someone telling me that global warming doesn’t exist because temperatures have flattened out in the last 10 years. It’s like saying we’re only going to fall six inches, so we can declare that the other 200 feet we’ve already fallen is “irrelevant” because it isn’t recent enough.
Therefore I ask, “Why did you start ten years ago and ignore the other data? How can you prove that it’s irrelevant?”
[QUOTE=intention]
There is a more interesting anomaly in the cited temperature record, however. This is the fact that, while the land areas of the Northern Hemisphere have warmed 1979-2006, there has been no significant warming of the corresponding land areas of the Southern Hemisphere … I have never read any explanation of that fact.
w.
[/QUOTE]
Wouldn’t this be expected, given the differences in land mass between the hemispheres, and more importantly, the huge differences in CO2 emissions? It’s been a long time since I studied meteorology, but I dont recall a lot of currents crossing between hemispheres.
[QUOTE=ClimateGuy]
Using the laws of conservation of energy how does El Nino generate heat to increase the global temperature?
[/QUOTE]
El Nino does not increase global temperature. Instead, El Nino increases surface temperature by redistributing warmer Western Pacific water over the Eastern Pacific, increasing stratification of the water column and preventing the upwelling of cold, deep Eastern Pacific waters to the surface. There may also be albedo effects, but that’s beyond my area of knowledge.
See this pair of images - the top image shows sea surface temperatures during an El Nino year, the bottom during a non-El Nino year. The important thing to note is that all the temperatures measured in these are at the surface.
Confirmation from JPL that the 2006 El Nino was much weaker than the 1997-1998 El Nino.
