Friday, November 20, 2015

Climate Change - Understanding Global Temperature Calculations

This post is kind of an aside but the article from The Telegraph from last February regarding "adjustments to actual temperature readings" is making the rounds again.  A commenter on FB posted a link to someone's blog post that had two very interesting videos embedded.  The text of the post was pretty much useless as it was simply Climate Change Religion attack jargon.

I am and remain a climate change skeptic simply because I hate the bullying tactics of the Climate Change Religious against anyone who dares to question anything.  People that desperate to squelch dissent must not be too sure of themselves.  And if most of them know as much about climatology as they do about GMOs, one does well to ignore them. They are simply anti-Exxon and anti-Monsanto.  In orhter words they have politicized science.

Here is NASA's take on it from 15 years ago and it is much more reasonable than the doomsayers would have you believe.  There are questions being asked by scientists.  We have learned a great deal since then, of course, but the question still remains, how much of global climate change is anthropogenic and how much has natural causes

These two short videos explain a great deal about how global temperature is calculated and why and how adjustments are made. They are made by a real scientist who explains things very clearly and gives you the data sources and software to do your own calculations if you wish.  Quite different from Dr Mann of hockey stick fame.

This picture is a screen capture from late in the second video.

The bottom pictures and chart show the coverage of earth and ocean surface by temperature recording devices, increasing from about 40% to about 80% from 1900 through 1970.  The top chart is a combination of all earth temperature records adjusted (dark red) and raw (light).

Global temperature is gradually and seeming inexorably increasing.  However you can see the oscillations that occur about every 30 years, so obviously there are other things happening than just GHG.  I can vouch for the 50's, 60's and 70's.  We had real winters then. But in the late 70's things warmed up and kept warming up. Though if you look at the top of the graph we seem to be headed into another "flattening" of temperature rises.

What will happen at the end of this current cycle (2040-2050) is anyone's guess.  Will the temperature again shoot up as it did for the past 30 years or are we headed into a cooling period? And how will it play out regionally? John Reader's "Africa: a biography of the continent" describes the effect of "localized" climate changes over the centuries.

A great deal of research is being done to try to hedge our bets as to which way the climate will go, with most seemingly favouring increased temperatures, though it is not the 95% that folks like to claim.  Regardless, the social impact and environmental hazards, over and above CO2, of coal, oil and gas should be pushing continued development of renewable energy sources.


BBC said...

Nature just has to kill a bunch of us to put things in balance again.

Raven Onthill said...

Dr. Cowtan, regardless of his abilities as a chemist and crystallographer, is not a climatologist. Most of the scientists critical of climate change any more are either in another field or in the pay of the fossil fuel energy industry. A link that responds that piece is here:, but it appears the site is under attack, and can't be reached.

I can't see how the decades of work that have made the case for anthropogenic climate change can be refuted at this point. The growing seasons have changed, the Greenland ice is melting. I don't know what to make of the new Antarctic data yet, but it's unlikely to change the overall picture.

Raven Onthill said...

Cached Google post.

Debunking: "Three stations. For comparison, global temperature collections contain thousands of stations. CRUTEM contains 4,842 quality stations and Berkeley Earth collected 39,000 unique stations. No wonder some are strongly adjusted up, just as some happen to be strongly adjusted down. In fact it would be easy to present a station where the raw data shows a decreasing trend of several degrees being adjusted upwards, but then the reader might start to think if the raw data is really better." — Climatologists have manipulated data to REDUCE global warming

If asked, I'd have to say that the reality of global climate change has consistently outstripped the predictions. Scientists are inclined to be conservative, and under much pressure to underestimate the changes. On top of which, the simple models of northern ice have turned out to be too simple; as Hansen thought was likely, the processes are non-linear and run faster than the simple estimates used in modeling.

The Blog Fodder said...

It is a toss up whether we will kill each other first or whether nature in one form or another will do it for us. We haven't had a really good disease outbreak since the 14th century.

The Blog Fodder said...

Dr Cowtan is not critical of climate change, not even anthrogenic, regardless of his qualifications. If you listened to the videos he is in fact responding to the Telegraph article, supporting NOAA and others who adjust temperature data of individual weather stations. I have done enough research myself in a previous life to know about outliers, missing data, etc so his explanations were quite useful.

The case FOR climate change is quite obvious. It has happened before and is happening again.

Cheryl Rofer said...

I suggest looking at up to date material rather than material from 15 years ago. Modeling has come a long way since then, along with much of the other data on global warming that is collected.

The international body that has the greatest overview on such things is the Intergovernmental Panel on Climate Change. Their writeups are reliable, although I have found the website not entirely helpful to navigate.

On issues like this, it's important to take a look at the whole of the evidence. That's hard for us who don't do that as a full-time job. I know I tend to focus on particular things like glacier melt (which is looking pretty scary). Putting the whole picture together is IPCC's job. They do a pretty good job at it.

Raven Onthill said...

Tweet, showing size of corrections:

They are minuscule.

The Blog Fodder said...

Agree 15 years is an old article but it is hard to find articles written in language I can understand that don't shriek at me for being a Nazi Holocaust denier for asking a question. If "the debate is settled" then it isn't science. We will be lucky to know in a hundred years answers to today's questions. There is no question that the climate is changing and certainly glaciers are melting. That GHG is involved is also beyond question. But how much and how GHG interacts with various natural cycles, I do not know. If there are clear simple videos like Dr Cowtan's or articles please point me to them.
I am a skeptic, not because I doubt the SCIENCE, but because of the bullying of skeptics by the climate change religious. You want to force me to believe, then FU.
The IPCC is a UN organization is it not? They are no less political than big oil. I have read enough of UN stuff on livestock to know that I trust them as far as I can throw them when it comes to common sense.

The Blog Fodder said...

Agree with your first paragraph which is why I wrote the blog. Dr Cowtan's videos explain it very clearly.
As to the second paragraph, I expect you are right. Scientists tend to be conservative as they like their conclusions to be based on fact not hyperbole. Shouting the sky is falling may be exciting but if you don't have the data to back it up then you are not a scientist, you are a politician. The climate may well be changing faster than the models predict. We should know the answers in another hundred years or so.

Diane Henders said...

I'm agnostic on the topic of climate change as a direct result of human activities. When the emotional hyperbole and political machinations are stripped away, the only quantifiable data we have is that there is currently a measurable warming trend in global temperatures. The problem is that we only have verifiable temperature data from a comparatively miniscule portion of the earth's history.

We infer from archaeological study that there have been quite a few significant warming and cooling trends in the past. That proves nothing on either side of the argument. It doesn't prove we aren't contributing to global warming this time around, but we also have no evidence to conclusively prove that we are affecting the natural cycle significantly... because we don't have enough hard data to determine what the 'natural cycle' is.

From a pure-science standpoint, it's impossible to establish causality except through retrospective examination, and we simply don't have enough data yet to form a statistically significant sampling. Ask me again in a few thousand years...

Diane Henders said...

...but let's not lose sight of the main issue: cleaning up our emissions will benefit everybody, regardless of whether the emissions have any effect on global temperatures. I like breathing clean air and drinking clean water. I kinda suspect future generations might like that, too.

Cheryl Rofer said...

It's possible to say that the debate is settled and still have it science. The debate is settled on the role of cigarette smoking in lung cancer. The debate (which went up until the 1960s) is settled on continental drift. Science settles some of these questions and moves on to others. That human use of fossil fuels is causing global temperatures to rise at an unprecedented rate is settled science.

Nobody has all the details on how much and how that warming interacts with various natural cycles. That involves quite a few big questions and many smaller ones. That doesn't mean that the science isn't settled on the effect of our rapid addition of carbon dioxide to the atmosphere.

I agree that some of the arguments and arguers can be bullying. I'm not pleased about that, but, as they say, oh well. People sometimes do that when they feel strongly.

I've done some modeling of the type done in climate modeling, and I've also done some collecting of large amounts of data to make a bigger point. Neither is intuitively obvious as a method, and the results may be less obvious. In fact, because I had worked with that kind of model, I was suspicious of climate modeling at first. But that was before I had spent a lot of time with my models, and it was thirty years ago. Models have improved a lot since then, and I have watched the progress enough to be confident in the overall conclusions.

Yes, IPCC is a United Nations organization, but the scientists it relies on are independent researchers from all over the world - university and government scientists from many different countries. My experience of the International Atomic Energy Agency, another UN scientific organization, is that they are extremely independent and nonpolitical. I suspect this varies from one organization to another.

The Blog Fodder said...

That is my take on it too, though I believe we are contributing but how much (possibly a great deal) and how it interacts are my questions.

The Blog Fodder said...

Exactly my point as well. Big Hydrocarbon must love the Climate Change debate as we are arguing about CO2 while they destroy the planet with activities and pollutants that we KNOW about and that need to be controlled/stopped.

The Blog Fodder said...

Agree totally. Dr Cowtan's videos show that clearly.

The Blog Fodder said...

If someone like you with experience in complex modeling thinks that the three main models used to predict the effect of GHG on global temperatures are reasonably good then I will accept that. Thank you.
I have heard it said that evolution is a settled science but they are coming up with new discoveries all the time. So I guess then the general idea of evolution is settled but the details are yet to be worked out.
I will check out the IPCC site. UN sites are usually difficult to navigate. (For sheer impossibility, try Government of Canada immigration sites)
I am so glad to see you back in the blogosphere. I have missed you on Nuclear Diner.

The Blog Fodder said...

Also, thank you for your comments and patience.

Cheryl Rofer said...

Thanks for your confidence.

The new discoveries in evolution are details on the main story, which is settled. Likewise, the fact that human-made carbon dioxide is causing significant global warming is settled. The exact effects on glaciers and deserts, food and disease have not been fully worked out.

I'm not entirely happy with the IPCC site. See what you think.

I have been around. The Nuclear Diner site is accessible to readers, but we have not been able to post there for a while, and we haven't been able to fix that. Some readers have had trouble accessing it, too.

So temporarily, I've set us up at WordPress. One of these days, I hope to get it all together again. New posts will appear at the WordPress site until then.

What do you think about the cutoff of electricity to Crimea?

Raven Onthill said...

I misunderstood — sorry.

The Blog Fodder said...

I do not write very clearly many times. I am skeptical but trying to learn. Canadian climate scientists have just updated their website with a whole bunch of stuff now that they are allowed to talk to the public again. I am reading some of it.