Why are some people not convinced that temperatures are contuing to rise in the last 5 years?

Question

Here is the trend in recent temperatures:

http://tamino.files.wordpress.com/2007/07/lsst.jpg

http://data.giss.nasa.gov/gistemp/graphs/Fig_E.lrg.gif

http://data.giss.nasa.gov/gistemp/graphs/Fig.C.lrg.gif

In the face of this data why do some still claim that warming has stopped?

I picked out 5 years because that was the timescale mentioned in Amancalledchuda's claim. I see to that you are claiming things have cooled since 2003, did you look at the actual data I posted because this refutes your claim that the Earth has cooled since 2003.

I see that amancalledchuda has re-emphasised the claims with regard to a cooling trend since 2002. I realise that you may have missed my pot on this, but here it is again (I must emphasise that you are cherry picking):

First, thank you for providing us with the link to your source of info. Now, there is a serious problem with your methodology and I'm going to prove it. Have you experimented with different input years within the last 7 years? If you had done this then you may have realised that your methods are incredibly sensitive to the input years that you use. In fact, in my experiments I've found that you have to be exceedingly selective about which years to use if you want to see a negative trend. Here are some examples (please feel free to test this out using the link below):

http://www.co2science.org/scripts/CO2Sci...

2002-2006 (Chuda's example): slope is -0.001516

2003-2006: slope is -0.008345

2001-2006: slope is +0.009202

2001-2005: +0.022082

2000-2005: +0.038309

2000-2006: +0.024592

So, we have two negative trends in the last few years but as a whole in the last 6 yes we have clear upward trends, but what of the last ten years?

1996-2006: slope is +0.022542

I think this is truly staggering. I've not seen such a clear example of cherry picking before. Chuda, how long did it take for you to find one of two negative trends in that dataset? Can you not see how much you had to contrive to get your result? Please look at the data as a whole without cherry picking magic years to compare because it's the only honest way to do it:

http://tamino.files.wordpress.com/2007/07/lsst.jpg

My best adice is to look at all of the data and avoid examing trends over a four year period which are highly likely to be influenced by natural variability rather than some other climatic influence. Looking at the graph produced fromthe temperature records shows that Chuda's claims are totally spurious.

RE: data visualisation, there are different ways of viewing the same data. The two GISTEMP graphs are slightly different, try going to GISTEMP and look at their different products. The Tamino link is actually a plot of monthly averaged temperature which is a duplicate of one of the GISTEMP graphs, bu the Tamino graph shows more of the data i.e. back to 1980 ish rather than 1997.

A final point, all of your caveats are pretty meaningless in the face of 5 minutes spent with the CO2science trend calculator which show just how selective anyone would have to be to arrive at your result. My central point, the caveats are irrelevant because on the whole the data simply doesn't support what you are saying. Clearly you think that by extending the supposed cooling trend it will show something....wrong. If you extrapolate the data further in time it wouldn't show a cooling trend, it would show a warming trend.

TOMCAT,

NOAA haven't re-constructed a global average temperature, GISS at NASA have, I lnked to that data, if you don't like what it shows that is not my problem.

Chuda,

Thank you for a more detailed explanation. However, this still doesn't change anything. You are asserting that there is a downward trend in temperature, yet as my analysis shows this interpretation is highly sensitive to which years you pick. In fact, if you do several similar analyses you end up with more instances of warming than cooling, and this doesn't seem very surprising given what the temperature trends show:


http://tamino.files.wordpress.com/2007/07/lsst.jpg

All of your caveats don't mean a thing because there isn't even a cooling trend, so why are you talking about one as if it exists? Same to you TOMCAT.

Chuda,

You accuse me of something despite having not read the details on each of those graphs. There are different ways of looking at the data, this is what the 3 graphs do, nothing else. I was not trying to "fool the gullible", I was merely trying to present different perspectives on the same data. Please explain why these datasets show a cooling trend in recent years despite them showing a warming trend.

Here is the other data set from the Hadley Centre and from UEA:

http://en.wikipedia.org/wiki/Image:Instrumental_Temperature_Record.png

Again, a trend line through the most recent years shows a continued warming. So you can't accuse me of being selective. The trends between GISTEMP and HAD-CRUT may differ but these differences are well accounted for by experimental error i.e. +/- 0.05 oC.

The main reason that I displayed the montly averages is that it is easier to visualise the real trend, the yearly averaged plots can be very deceptive and without a mathematical fitting program it is difficult to visualise the real trend. Thankfully HAD-CRUT have done this for us and you can the upward trend in temperatures in their data.

Answer 1

Who cares? We can't do anyhting about it anyway.
We'll use more t-shirts and less coats.

Answer 2

OK Paul, I’ll bite ;)

I read a report recently that claimed that there appeared to be a correlation between the activity of the Sun’s magnetic field and the intensity of future sunspot cycles. Based on this correlation the authors predicted that the current and next sunspot cycles would be increasingly quiet, and this *might* result in some cooling here on Earth.

So, having read this I looked at the temperature record to see what it had been doing recently and discovered that, according to some data sets, there has been no warming since 2002.

Based on this I speculated (since speculate is all I could do – it is plainly far too early to tell for sure) that the predicted cooling may already be having an effect.

I based my observation on the HadCRUT3 temperature data set (which can be found here… http://www.co2science.org/scripts/CO2ScienceB2C/data/temperatures/hadley.jsp ) which shows a trend of -0.001516°C per year since 2002 (effectively no trend) and the MSU Satellite data set (which can be found here… http://www.co2science.org/scripts/CO2ScienceB2C/data/temperatures/msu.jsp ) which shows a trend of -0.001390°C per year since 2002 (again, effectively no trend).

Now, I’m perfectly willing to accept that five years is too short a time to prove anything, but the evidence presented here certainly allows for the possibility that the predictions mentioned above *may* be correct.

So, it will be interesting to see how the temperature trends pan out over the next ten or fifteen years. If the expected quiet sunspot period does cause some cooling, it would seem to me that this will put a rather large dent in the theory that the Sun is irrelevant compared to the overwhelming influence of manmade GHGs – as the alarmists would have us believe.




Incidentally, Paul, the data on your three graphs look awfully similar. Are you sure they’re not all from one data set? Certainly the second two are from the GISS website, which suggests they are both derived from Hansen’s GISS data set. The first one, while from another website, also appears to be showing very similar data. Are you showing the same thing three times, perhaps?


:::EDIT:::


So you do admit that all your data is the GISS temperature data set? So why show the same data 3 times? Is it because you thought you could fool the gullible into thinking that you had three separate sources supporting your point of view?

It does amuse me that global warming alarmists like you, Paul will constantly talk of the “consensus”, but will then continuously quote the minority view regarding observed temperature by only ever quoting James Hansen’s GISS observed temperature data set, which just happens to show the biggest rise – the only data set that shows 2005 warmer that 1998 for example – and the only data set that shows Hansen’s 1988 predictions of temperature rise as being accurate. Some would argue that it is in Hansen’s best interests to inflate his data set to allow him to claim he was right back in 1988, so we shouldn’t trust the GISS data. You would naturally disagree, of course, but I would expect no less from an alarmist.

You constantly drone on about the fact that I’ve cherry-picked data, but we’re talking about sunspot cycles here, and they only last 11 years. If we’re in the middle of the first of two cycles that are expected to be increasingly quiet, what relevance does the temperature back in the late 70s have? Or, for that matter, 10 years ago, or anytime before the sunspot cycle began.

Plainly, what the temperature did before these reduced activity cycles began has very little to do with the discussion about what effect they’re having.

Yes, if you select a year before 2002, you get a warming trend, but if the sunspot cycle only stated to have an effect in 2002, then the trend pre 2002 is irrelevant to the issue at hand. Isn’t it?

I say again, Paul, I’m not trying to claim that global warming has stopped. I’m merely suggesting the possibility that our current sunspot cycle, and the next, may have a negative effect on global temperature. Currently, some observed temperature data sets allow for that possibility to be valid.

Does this prove anything? No, as I’ve said before. An examination of the last thirty years of data shows that there have been several other occasions where we had a four-year trend of cooling – that evidently weren’t the start of a long term cooling trend.

Thus, as I’ve have also said before, the next ten of fifteen years will be very interesting. *If* (and I accept it’s a big ‘if’) we do see cooling, it will be most amusing watching the Alarmists squirm. I’m sure you’ll come up with some valid excuse; sulphates perhaps? Oh no, you used them to explain the 40s – 70s cooling. The oceans? Nope, you used the ‘ocean notion’ to explain why temperatures haven’t risen as fast as models predicted. Well, I’m sure you’ll come up with something.

Answer 3

I can't speak for everyone, and I am not sure why you picked such a specific number of 5 years. But when you choose to look at the unsmoothed surface temperature record you are looking at the effect of the climate and not necessarily the cause. People interested in doing serious climate research often look at atmospheric temperatures to attempt to understand and or predict future trends. Temperatures in the atmosphere as well as tropical sea surface temperatures have been cooling since 2003 (that is a fact!), if this trend continues it could be the precursor of a very serious swing in climatic change that could present humanity with some very difficult challenges.

http://www.ssmi.com/rss_research/climate_change_plot.html

http://www.ncdc.noaa.gov/img/climate/research/2006/ann/msu2006-pg.gif

EDIT:

Paul, who cares about what GISTEMP says, it does not refute anything when are studying trends about the atmosphere. That is where earths greenhouse process functions. Surface temperatures are a very complicated business, but if you insist the surface does not indicate warming for the last few years, if you believe NOAA.

http://www.ncdc.noaa.gov/img/climate/research/2006/ann/msu2006-pg.gif

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Answer 4

Since world temperatures have been rising since the cold period known as the medieval "Little Ice Age" it could be part of a trend that is entirely natural. There is also evidence that much of the GW hysteria is based on inaccurate information, lies and false data. There is also evidence of some cooling.

At the end of the last major Ice Age10,500 years ago, the climate became much warmer than today and remained so for 7,500 years, then it cooled and warmed to warmer than today during the time of the Roman Empire, up to when the Vikings colonised Greenland, then came the medieval Little Ice Age when the Baltic sea froze over in winter. The LIA actually had its last blast in 1815, freezing Napoleon's army in Russia and causing snow in every month of the year. Temperature records started being kept about 1850.

Considering the last 10,500 years please define what is a "normal" climate". How can 150 years of recent records be considered "normal"? Why have Hansen and other pro-GW scientists found it necessary to "adjust" historical data to make their theories work?

Could part of the problem lie with Leftist politicians who want to use the issue of GW to gain power and tax revenue so they can buy votes with government giveaways? What about their fellow travellers in academe and the media who support GW?
If you don't agree with them you are not intelligent, a false scientist, paid off by special interests, not deserving of research grants, too incompetent or dishonest to be published, not qualified to be a professor. The tactics are also used by the Left against those who disagree with them politically, because for all their posturing about free speech, if you disagree, they want you to just shut up and will use pressure to make you shut up.

Too many have become "True Believers" in GW and questioning it, or showing facts that question their beliefs is cause for burning the questioner at the stake for heresy. Actually I don't care if we have Climate Change. Change is only change, not a disaster. Too many environmentalists equate change with destruction and damage, they want a nice solid status quo. Warming would increase rain and farmlands and reduce deserts. Even if the sea levels went up it would take enough years so that everyone could walk to higher ground, even the animals. There would be time to build dikes to protect important cities.

Algore's Prise and his fictional movie have nothing to do with Peace. I know I cannot change the mind of a "True Believer" with these comments, but those others who still are able to think, please do so, do the research on both sides of the argument with an open mind and notice how the Left treats those who disagree. What kind of world do you want? Free and open or dominated by one group's way of thinking?

Answer 5

It's simply wishful thinking - trying to cherrypick and manipulate the data in any possible way that might appear to support their denial.

Basically they cherrypick the only possible points which seem to illustrate the amazingly long-term 5 year cooling. Of course, since 2007 is on track to be the warmest year in recorded history, this manipulation will only work for another few months, so they might as well enjoy it while they can.

Answer 6

Because the data is so "rough", it jumps around a lot year to year.

To most all non-scientists, the concept of something like a 5-year rolling average is like Ancient Greek - completely not understandable, maybe even suspicious. To a scientist, of course, it's a very valid way of smoothing data like this.

It's yet another example of confusion between short term weather and long term climate.

Of course, some are deliberately confusing the two, but for many it's a honest mistake.

Overemphasis on "the warmest year (or years)" feeds right into this confusion. And that's a concept both sides are guilty of overemphasizing.

Answer 7

a lot of people refuse to accept reality, for example in the 60s the theory of homeostasis (the crackpot theory that the climate had reached a balance & would remain the same for centurys)was widely believed by the hippys that developed it.
when in fact the climate has always varied wildly between extremes through geologic history long before any humans exsisted on earth to to record it.
it seems now that human activity is altering the climate so that much more airable land in the northern hemisphere ( what is now useless tundra) in canada & russia will become farm land to feed more people so the human population can continue to increase.

Answer 8

I think some people who claim that warming has stopped don't really beleive that, they're just saying it in an attempt to support their own viewpoint that global warming isn't happening.

If they do genuinely beleive it then it demonstrates they don't have an understanding of some of the most basic aspects of global warming and the climate. I would guess such people are simply repeating what they may have heard or read without actually understanding what it is they're talking about.

Answer 9

I am least convinced.I find that summers are becoming less hot and winters becoming cooler.Rainfall in most part of the world increased.There is general increase in vegetation and increase in rain forests.It is just difficult to believe a theory based on temperature measurements at a limited number of places

Answer 10

because the conservatives have told the Boobus Americanus that it is all a lie by the conservationists to take their jobs away by shutting down filth spewing dioxin making plants and send them to their bleeding heart relations in third world countries. When in reality, something can be done by enforcing the EPA regulations that for some strange reason, Bush hack Christie Whitman allowed to be gutted while she helmed the EPA.

After all the conservatives are good God fearing, muslim hating, flag waving American Good ol' boys, so they wouldn't DREAM of ever telling a lie for profit now would they?

Answer 11

Because they haven't, the last hottest temps were in the 1930's and 40's and then 1998.