Showing posts with label temperature predictions. Show all posts
Showing posts with label temperature predictions. Show all posts

Tuesday, February 21, 2012

Predictions of climate change

There are a couple of controversial items that have made it into the mainstream press recently that seem to have stirred a little controversy, and which are worth at least a mention. (And please note that the original post has been updated).

The first was the Opinion piece in the WSJ back in January in which 16 scientists wrote that there was no need to panic over Global Warming. They note, in their letter
Alarmism over climate is of great benefit to many, providing government funding for academic research and a reason for government bureaucracies to grow. Alarmism also offers an excuse for governments to raise taxes, taxpayer-funded subsidies for businesses that understand how to work the political system, and a lure for big donations to charitable foundations promising to save the planet. Lysenko and his team lived very well, and they fiercely defended their dogma and the privileges it brought them.

Speaking for many scientists and engineers who have looked carefully and independently at the science of climate, we have a message to any candidate for public office: There is no compelling scientific argument for drastic action to "decarbonize" the world's economy. Even if one accepts the inflated climate forecasts of the IPCC, aggressive greenhouse-gas control policies are not justified economically.

Their letter received a response from a group that included some of the more prominent (and funded) of the climate change advocates, which avoided the discussion of funding, but rather spoke to the eminence of those who are forecasting gloom.
Do you consult your dentist about your heart condition? In science, as in any area, reputations are based on knowledge and expertise in a field and on published, peer-reviewed work. If you need surgery, you want a highly experienced expert in the field who has done a large number of the proposed operations.

You published "No Need to Panic About Global Warming" (op-ed, Jan. 27) on climate change by the climate-science equivalent of dentists practicing cardiology. While accomplished in their own fields, most of these authors have no expertise in climate science. The few authors who have such expertise are known to have extreme views that are out of step with nearly every other climate expert. This happens in nearly every field of science. For example, there is a retrovirus expert who does not accept that HIV causes AIDS. And it is instructive to recall that a few scientists continued to state that smoking did not cause cancer, long after that was settled science.
(You will note the little unsubtle ad hominem at the end.)

The original authors have now replied. I will quote the reply under the fold, but the first part of their response points out that, for major surgery, it is often best to get a second opinion, and to look at the record of the proposed scientists. They then put up a graph of the accuracy of the IPCC predictions for temperature rise, which I thought worth repeating.

IPCC projections for temperature rise, against reality. (WSJ)

UPDATE
There is a response to the more recent letter on RealClimate which complains that the WSJ plot does not include error bars, and that, when those are included, that recent temperature plots fall within the range of the predicted models. I have appended that plot to the end of this post.

Te response begins thus:
We agree with Mr. Trenberth et al. that expertise is important in medical care, as it is in any matter of importance to humans or our environment. . . . . . . . . .In this respect, an important gauge of scientific expertise is the ability to make successful predictions. When predictions fail, we say the theory is "falsified" and we should look for the reasons for the failure.
They point out that the heat that was to have raised the temperature has now been suggested as having gone, instead, into the oceans, but point out that there is no evidence to sustain that theory.

They note that the Earth has been warming since the Little Ice Age (for which there is much evidence) and prior to the LIA there was the Medieval Warming Period, and before it the Holocene Climate Optimum, neither of which can have been caused by greenhouse gases but which instead point to a natural cycling of temperature, which current science has not disproved as a cause of the current warming period. And they also express concern about the statement that "decarbonization would drive decades of economic growth."

Of course a wind farm, or solar farm employs significantly less workers than a coal mine (though arguably more than an oil or gas well - though not if one includes the refineries - since when it gets to power station levels both should surely balance out). I rather suspect that this is not the end of the discussion, and that the debate is starting to get a little more public exposure than it has been able to achieve in the past.

In passing I should note the small furor about the release of some of the documents from the Heartland Institute, mastered by one Peter Gleick, who was a MacArthur Fellow, has confessed to dishonestly obtaining and then releasing them. Not apparently that this is stopping the climate change advocates from pointing out the money that the Heartland Foundation has (though virtually none report on the relatively roughly hundredfold larger size of the sums of money being put into work that advocates climate change - but with money comes power and access, and the Heartland group has much less). I guess just because you're a recognized genius doesn't mean that you can't do stupid things.

However, the other thing that is worth a comment is that there seems to be a growing recognition that biofuels may not be the savior of the atmosphere that they have been purported to be. Apparently the Friends of the Earth have issued a report which indicates that switching to biofuels won't have much effect on cleaning up the air, in fact the switch may make things worse. At the same time the switch may cost drivers in Europe something on the order of $24 billion a year. And in the process of looking into the topic there is another new report (unfortunately behind a paywall) which suggests that much of this was known before the regulations were put in. Bishop Hill has a post on the report, which suggests that some un-named, but central and powerful individual, was able to manipulate the EU into making the moves that have led to the adoption of the 10% biofuel requirement, without adequate consideration of the evidence. Apparently none of the non-supportive data was made available. I wonder why that sounds familiar?

And in passing, and closure, I wrote, in the past about Dr. Hansen's predictions of global warming that were one of the seminal events that got the climate change movement the financial success that it has since achieved. It is interesting to take the graph he used, and add some of the data from the plot above. It would appear that more than one computer model has been falsified. Because Dr. Hansen's models seem to use a different zero, I have slightly adjusted the values from the curve above to extend the data on actual temperatures relative to those predicted. You can see that they are starting to fall below the values that Dr. Hansen predicted would only be achieved if there was a radical reduction in carbon dioxide and the greenhouse gases - which hasn't happened, and so would perhaps indicate that the effects of said gases are less than he was predicting.

Projected temperature rise anticipated by Dr Hansen (Dire Predictions)

The plot which RealClimate have used as a rebuttal is this one.

Real Climate plot showing the error bars that they state exist for the models.

It is an interesting point though since all the model error bars are conflated makes it difficult to see how much validity there is to the argument.

Incidentally Profesor Lindzen gave an excellent talk (pdf) at the Houses of Parliament in the UK the other day. It got favorable coverage in the Independent.

UPDATE: There have been a couple of posts over at Watts Up With That? (WUWT) that provide better versions of the plots than the one I gave above. The first points to a presentation by Dr. Evans, which contains this plot:

Temperatures as measured by satellite against Dr. Hansen's predictions in 1988.

The other compares the IPCC predictions with actual temperature data, and quotes a post by Clive Best, that contains this plot:

IPCC predictions of long-term temperature change.

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Saturday, April 10, 2010

California temperatures, GISS USHCN, E.M. Smith and Anthony Watts

This is the day that I am going to look at the temperature records for California. It was the truncation of the number of stations in the GISS analysis that led E.M. Smith to his post, that started me off into taking a significant look into the temperature records. His concern was initiated by the discovery that the number of stations being used by GISS to monitor CA temperatures had been cut to four, all located near the coast. So does this have any meaning? The task begins, as I outlined at the beginning, by getting the data from the 50 USHCN stations and also inputting the data from the GISS stations.

There will be a slight pause while I do this. And after loading in the data from the 54 USHCN stations there are a few observations. Firstly the data from Death Valley is missing three data points (1896, 1897 and 1899). So noting that 1896 was 0.29 degrees above the state average, and that Death Valley is on average 16.62 degrees above the state average, suggests that in 1896 the temp there would have been 75.92 deg. And so we enter that and do the same for 1897, and 1899. And in passing I note that there are a couple of stations (Death Valley and Indio) that are below sea level. Wonder how that will work out. There don’t seem to be that many in the heights, but we’ll see how the graphs plot out. This is the correction that I explained in more detail when I was looking at the data from Colorado and found some values missing.

Now I get the four station data from GISS that Chiefio lists, which are San Francisco, Santa Maria, Los Angeles, and San Diego, which I download from the GISS site and at first none of these are on the GISS list. So I go back to the station locator and type in San Francisco and I get four stations and checking with Chiefio’s list by grid reference the top one is the one he cites. (and it is the one that has data from 1880 to 2010). So the next one on his list is Santa Maria, try that through the station locator and there are two locations, but neither has a full set of data!! In this case it is the lower of the two, which gets me information from 1948 on. Los Angeles data is all there, as is San Diego’s, though again one has to choose the longer history site from the four available. Phew!

OK so what have we got? With the varying conditions in the state (and particularly since we are coming down from the mountains to the sea) I will expect that there will be some influence of longitude, but given the concentration of data along the coast and at low elevations, I am not sure how it will end up. And then there are a lot more towns with larger populations that we have seen in the states we have looked at until now. Checking populations Cedarville was too rural for the usual city-data site, so I got the population from neighborhoodlink . Cuyamaca is a State Park with zero inhabitants (I put down 1). Electra also appears to be on none of the lists – (So looking at the one site with info, I put down 10). Lake Spaulding is a fishing camp (no data – suggest 5).

And having put in all the data (using the elevations of the airports for the GISS stations) one finds some interesting results. Firstly how do the GISS stations compare with the USHCN data?

While the GISS stations are on average 1.6 degrees warmer than the USHCN stations, the difference between the two is increasing:


(Note however that the small number of GISS stations relative to the number of USHCN stations means that when one does a total average for the state the differences induced are quite small.) Even without the GISS station contribution, the temperature in the state has been increasing, though the rate seems relatively constant since about 1900.


The state is a relatively long one, and there remains a strong influence of latitude:


I had expected, since the mountains are on the East and the sea is on the West, that there would also be an influence of longitude.


And that, at any significant level is apparently a wrong assumption.

Hmm! Well how about height, that has been fairly consistent.


And so it is again, though note that those below sea level seem to be even hotter than predicted.

Now one thing that we also can check on, given that there are significantly more stations in this state, is as to whether the scatter in the data is getting worse. This is something that would be suggested by Anthony Watts survey of stations. The premise has been that as the maintenance on the stations declines so the scatter in the results would get worse. This would be reflected in an increasing standard deviation across the stations in the state.


And while there was no such trend in other states, it is very clear and significant in California.

And with respect to the influence of population, I am still seeing that logarithmic fit, with the knee of the curve being at around 10,000 folk. Thus if GISS is cutting off all the influence of towns below that size, and just calling them rural, the evidence continues to suggest that this is a significant error.


Well I also suppose that this is one of the states where there are enough larger cities in the data bank that we can plot this on a log scale:


Correcting the individual temperatures as though the stations were at the center of the state (i.e. adjusting for latitude, as I did last time), one gets:


And then if one looks at the effect of elevation with latitude taken out of the data, one gets:


Again a clear correlation, except that there is a considerable scatter as one gets down to the range below about 100 m. Since this brings in the possible effects of the nearby ocean, and I am not sure how to isolate that at this time, we’ll leave that part of the analysis until we have more information.

The average elevation of California, by the way, is 884 m, and if you look at the plot above you can see that there are only 9 stations (out of 58) that are above that height. So if you do just an average of the data (which is what I have been doing) it will be weighted by the stations below the average elevation, and this will bias the results. By how much? Well we’re going to have to find more data before we can answer than question, and I suspect that it has to do with making adjustments for being close to the ocean.

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Saturday, October 31, 2009

Dr Hansen was wrong - let's change the subject

I have pointed out in recent remarks, that if the debate on climate change were being conducted under normal scientific conventions, then the predictions that were made by Dr. Hansen back in 1988 would, by now, be considered to have been proved false, since the predictions that he made on global temperature rise, and the path that temperature would take, have not followed his models. His predictions were based upon:
Scenario A assumes continued exponential trace gas growth, scenario B assumes a reduced linear growth of trace gases, and scenario C assumes a rapid curtailment of trace gas emissions such that the net climate forcing ceases to increase after the year 2000.
The carbon dioxide path has continued to move along the path predicted for scenario A, yet the temperature rise through today has not only failed to accelerate with it, as Dr Hansen predicted, but instead is much closer to following along the temperature curve predicted for scenario C.

Comparison of Dr Hansen’s scenario predictions against actual temperature anomalies (deg C) (prediction here and actual temp from GISS) Baseline 1951-1980 mean.

I took the data from the plot of temperature predictions that Dr Hansen provided, since it allows me to easily read the predicted temperatures, and I then re-plotted the data with the actual temperatures from the GISS website as the black lines, since the original plot only went as far as 2005. I did note that the tabulated data were slightly different from those of the actual temp data plotted in the 2005 curve, and used the more up to date ones for the entire series.

If one looks at the above comparison that Dr Hansen which is extended from the one made in 2005 the difference between the actual temperature and his predictions clearly show that the actual (black) temperatures are falling away from all but the C scenario (blue) a predictive future which was only supposed to occur if we did ameliorate carbon dioxide emissions. There is no accelerated warming, and there was no amelioration of the rising carbon levels, and so his predictions fail.

However, rather than discuss this rather interesting fact, the global “warming” community has managed, yet again, to divert discussion by dragging debate over a different topic of their choosing, so that this primary point can be hidden from public debate. Their topic centers on whether the globe has been warming at all, an issue that depends very much on where your temperature starts. They might have been somewhat embarrassed to begin with 1998 (as some more realistic of the proponents recognize, following their earlier use of that temperature to show how fast the temperature was going up). However the commentators have chosen, very carefully, to attack the suggestion that the temperature might be cooling, rather than the more relevant issue that the global temperature is not following the models. When you can’t argue, then change the subject.

Now, for what it is worth I have made clear that I am more convinced by the hundreds of peer-reviewed publications (such as those referenced by Jean Grove in The Little Ice Age, or by Brian Fagan in his books) that document the Medieval Warming Period and its predecessors and the intervening cold periods, such as those of the Dark Ages and the Little Ice Age. Thus the fact that the present warming period has not reached the extent of the last warming period, let alone those before it, does not unduly disturb me. (That is evidenced by the ground conditions – such as permafrost - in the Arctic inter alia, and the positions of the ecotones in Europe). Yet it is sadly a denigration of true scientific debate to see how vociferously those arguing for AGW change the topic, or readjust the data whenever they seem at the stage of losing a point in the debate.

If one accepts that we are in this cyclic series then arguments about whether by some fraction of a degree or other the temperature was warmer in 1934 than 2005 in the United States become significantly less critical. The question then becomes whether this Warming Period is significantly less warm than the last, or the one before that. The Roman period was apparently warmer than the Medieval one (the evidence coming among other things from the Roman ruins appearing out of the ice in the Alps), and both were warmer than we are now. But we also need to go back to those periods and see what the conditions were that developed in different parts of the globe (such as the extended droughts in what is now California) and learn from that information, and take precautions accordingly, recognizing what we might be facing as the climate changes. For if we do not learn from history, then we are bound to repeat it - as once was said.

The question as to why these periods existed – or whether the intervening cooling periods are the anomalies – is probably a much more worthwhile study, but given the urge that folk have to change the way in which energy is produced, and the vast fortunes that hang on the changes in policy that are being debated, somehow I don’t see much attention being given to those questions soon.

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