Global Temperature Trend Update—August 2009

Every month University of Alabama climatologists John Christy and Roy Spencer report the latest global temperature trends from satellite data. Below are the newest data updated through July, 2009.

The press release from the University reports:

Global climate trend since Nov. 16, 1978: +0.13 C per decade  

July temperatures (preliminary)

Global composite temp.: +0.41 C (about 0.74 degrees Fahrenheit) above 20-year average for July.

Northern Hemisphere: +0.21 C (about 0.38 degrees Fahrenheit) above 20-year average for July.

Southern Hemisphere: +0.61 C (about 1.10 degrees Fahrenheit) above 20-year average for July.

The global average temperature jumped 0.41 C from June to July, the largest one-month jump in the 31-year global temperature record, according to Dr. John Christy, director of UAHuntsville's Earth System Science Center. The global average went from normal in June to the second hottest July on record.

"Part of that is an artificial artifact of where we put the calendar boundaries," Christy said. "Warmth from the new El Nino was not felt at all in June but really got going almost from the first day of July."

At 0.41 C warmer than seasonal norms, July 2009 was second only to July 1998 (+0.51 C). July 1998 was on the back end of the most powerful El Nino Pacific Ocean warming event of the 20th century. That El Nino also caused the warmest monthly average temperature in the climate record: +0.77 in April 1998.

At 0.61 C warmer than seasonal norms, temperatures in the Southern Hemisphere in July tied May 1998 (during that big El Nino) as the second warmest month south of the equator. It was also the second warmest month on record in the Antarctic, where the average temperature was 3.11 C (about 5.60 degrees Fahrenheit) warmer than seasonal norms for the Antarctic winter. The warmest (compared to seasonal norms) was May 2002, when the continent's average temperature was 3.30 C warmer than normal. 

Comments

[Johnny Longtorso]

http://news.nationalgeographic.com/news/2009/07/090731-green-sahara.html

Sahara Desert Greening Due to Climate Change?

Desertification, drought, and despair-that's what global warming has in store for much of Africa. Or so we hear.

Emerging evidence is painting a very different scenario, one in which rising temperatures could benefit millions of Africans in the driest parts of the continent.

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.

If sustained, these rains could revitalize drought-ravaged regions, reclaiming them for farming communities.

This desert-shrinking trend is supported by climate models, which predict a return to conditions that turned the Sahara into a lush savanna some 12,000 years ago. ...

[John Thacker]

The sea ice extent number remains interesting. After 2007, there was a very plausible argument to the effect that all the melting ice in 2007 would lead to a positive feedback cycle of progressively less ice, since the ice coverage that winter would be mostly thinner, new ice. (Put another way, the extent measures area, not volume, so it can be misleading if the ice thins.)

But that didn't quite happen in 2008. 2008 was low, but not as low as 2007. What will happen in 2009? We're coming up on the crucial months that will show whether sea ice looks like it may go back to normal, or whether we really have transitioned to a permanent lower average.

[R C Dean]

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.

That would be change, and therefore is bad. According to the gospel of St. Gaia.

I seem to recall reading that the warming from CO2 at this point can be modelled at about .05 C, and due to saturation effects will cap at around 1.0 C (memory fuzzy on exact numbers).

All the catastrophic projections depend on various feedback loops. Any sign any of those are running per the projections?

[MikeP]

"Part of that is an artificial artifact of where we put the calendar boundaries," Christy said. "Warmth from the new El Nino was not felt at all in June but really got going almost from the first day of July."

Ever since I was a child I have been annoyed by this meteorological stupidity.

June 30... monthly rainfall to date: 1.43"; average monthly rainfall to date: 1.21"

July 1... monthly rainfall to date: 0.00"; average monthly rainfall to date: 0.04"

What a loss of data and precision! Is it really that hard to use a 30 day running average???

[juris imprudent]

Until someone can tell me what the optimum global temperature is, and have a solid scientific justification for it, there is no point in arguing over the year to year measurements (let alone the projections of the models).

[Paul]

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.

That would be change, and therefore is bad. According to the gospel of St. Gaia.

Agreed. Someone didn't get the memo. It's no longer Global Warming. It's Climate Change. The Sahara must remain a desert, devoid of rainfall and bereft of... green leafy stuff.

[EscapedWestOfTheBigMuudy]

What a loss of data and precision! Is it really that hard to use a 30 day running average???

Of course it's not.

But you'd have to explain exactly what you were reporting, and a lot of people wouldn't get it. There would be complaints. People understand the average for this calender month on the first try.

This is one reason why science reporting is hard.

As for the temperature trend graph, you don't get all-over-all-the-time data. Even from the satellites, so you have to bin the data somehow. Using months makes the data easy to report.

[A global temperature?]

How does the Earth even have a "global temperature?" The temperature varies so widely over the entire earth every second of every day.

How does one even start to figure such a number with any accuracy?

[?]

It can't be accurate.

But you can make it up, then say that you can't explain how you made it up to people who don't know you made it up, because SCIENCE.

[oldtimer]

But won't the new green shoots eat up all the CO2 and negate my new Cash for Clunker experience? I want my SUV back and I want it now !!.Fortunately I didn't take advantage of the program so I can drive around with the AC on and produce more of the CO2 and make the desert bloom. I'm doing my share for Africa.

[Ska]

Just don't let that song by Toto get stuck in your head. It'll ruin your weekend.

[Johnny Longtorso]

Just don't let that song by Toto get stuck in your head.

Rosanna?

[Ebeneezer Scrooge]

Emerging evidence is painting a very different scenario, one in which rising temperatures could benefit millions of Africans in the driest parts of the continent.

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.

In other words it would become, once again, similar to what it was, back from ancient Egyptian civilization up through Roman times. There was a lot more rain back then, and the climate shift that occurred has been cited as a contributor to weakening the Romans.

Of course, Chinese civilization started out (growing wheat) in the north China plains, where today there isn't enough rainfall for the Chinese to have gotten started. The "center" of Chinese civilization has been moving slowly south for over 2000 years -- a natural climate shift is believed to be the driver.

But never mind the details, we have a Gaia to worship.

[Chicken Bones of Justice]

"The warmest (compared to seasonal norms) was May 2002, when the continent's average temperature was 3.30 C warmer than normal."

I remember that! both coasts were completely under water.

[EscapedWestOfTheBigMuddy]

How does the Earth even have a "global temperature?" The temperature varies so widely over the entire earth every second of every day.

How does one even start to figure such a number with any accuracy?

It means a(n appropriately weighted) average. If you want to know the harry details you'll have to read the literature. I haven't.

Arguing over how that average should be formed, and what it really means, and what weighting should be used are all legitimate, BTW, but are matters for experts and quite beyond me. You can probably determine if there is or is not widespread agreement on these issues just but doing a literature search (without needing to fully comprehend the contents of the papers).

[SugarFree]

MikeP,

What a loss of data and precision! Is it really that hard to use a 30 day running average???

The growing season is often pegged to the progression of calender months. If you consider "June" to be a division of the growing season that has to have certain landmarks hit in order to insure a successful harvest, a running total is worse than useless. Crops need rain in varying amounts during the growth cycle. A deficit of rain in the spring means irrigation. A deficit of rain in the fall can mean a longer period for harvesting.

It is imprecise, but that's what the "Year to Date" total is for.

/rural upbringing

[SpongePaul]

It cant be accurate because we are looking at a very small slice of what 100 = years of temp ranges in oh a couple million years of temp variance. its like looking outside at midnight and declaring it will get even darker, you dont have enough data points for a real model. at the best you may be able to pick up statistcal blips, but that happens all the time.

[joshua corning]

hello El Nino warming event.

Also i think that graph is Watts's graph so be sure to credit it appropriatly.

[MikeP]

SugarFree,

The June 30 30-day running average can be called the June rainfall. The July 31 30-day running average can be called the July rainfall.

But on June 10 when you come back from Europe to hear that the June rainfall is zero inches, wouldn't you rather have heard that the 30-day rainfall is two inches?

[EscapedWestOfTheBigMuddy]

It cant be accurate because we are looking at a very small slice of what 100 = years of temp ranges in oh a couple million years of temp variance. its like looking outside at midnight and declaring it will get even darker, you dont have enough data points for a real model. at the best you may be able to pick up statistcal blips, but that happens all the time.

Err..don't mistake the question "Can we form a well defined and meaningful average temperature?" (for which the answer is probably "Yes.") for the questions "Is the time series data in hand adequate for making medium term climate predictions?" (for which the answer may well be "No.").

[Tony]

Is Reason gonna ever cite scientists besides Christy and Spencer (and Lomborg, though he's not a scientist) on this subject?

[SugarFree]

But on June 10 when you come back from Europe to hear that the June rainfall is zero inches, wouldn't you rather have heard that the 30-day rainfall is two inches?

Of course, but all I'm saying is that it's not a useful information format for the non-farmer. I don't like it either, but they really aren't talking to me or you when they say it.

[PantsFan]

For Reason on Lomberg, Go Here

[PantsFan]

Tony, are you a scientist?

[brotherben]

For the record, june here was hotter than a popcorn fart. Over 100 degrees evry day and nary a drop of precip. July OTOH was pleasant. Highs in the upper 80s and lower 90s and we got over 16inches of rain here at the house.

[brotherben]

I seem to remember a quote, I'll look for it, where Dr. Hayne said that the science of Global Warming is questionable science at best.

[Silentz]

Tony, probably as soon as the Global Warming Priesthood starts citing them.

[joshua corning]

I seem to recall reading that the warming from CO2 at this point can be modelled at about .05 C, and due to saturation effects will cap at around 1.0 C (memory fuzzy on exact numbers).

here:

http://wattsupwiththat.files.wordpress.com/2009/07/co2_temperature_curve_saturation.png

from this article:

http://wattsupwiththat.com/2009/07/15/9373/#more-9373

[mike]

well it was quite a few degrees below normal where I am in the northern hemisphere in both june and july. And wet. Very very wet.

[hmm]

What pros or cons come with using satellite data. I know NOAA had a slight issue or nonissue with their 1000 or so sites around the US and locations near tarmacs and such. But is satellite data better or how exactly is it collected?

Just curious.

[bookworm]

"What pros or cons come with using satellite data. I know NOAA had a slight issue or nonissue with their 1000 or so sites around the US and locations near tarmacs and such. But is satellite data better or how exactly is it collected?"

Satellite data is better because it doesn't have distortions like urban heat islands.

[max hats]

So, I see the new consensus is that global warming doesn't matter, with substantial holdouts in the global warming doesn't exist crowd peppered with a notable minority of the 'scientists are too dumb to read graphs' crowd. Noted.

[bookworm]

"Is Reason gonna ever cite scientists besides Christy and Spencer (and Lomborg, though he's not a scientist) on this subject?"

Tony, are you saying that Christy make up the graph because it didn't show what you wanted it to show?

[Tony]

Tony, are you a scientist?

No, that's why I have to rely on what the scientific consensus is to form an opinion. Not form an opinion and then find scientists (but mostly nonscientists) who agree with me.

[Tony]

bookworm,

Didn't say anything about Christy's methods. Just wondering when Reason was gonna take a scientific approach to science reporting, or stick with its propagandistic method.

[bookworm]

"Didn't say anything about Christy's methods. Just wondering when Reason was gonna take a scientific approach to science reporting, or stick with its propagandistic method."

I'm sure you would prefer they would report speculations from global warming alarmists like Hansen who have not proven their case that man's contribution to increases in CO2 levels are really going to bring us a disastrous future.

[bookworm]

"that's why I have to rely on what the scientific consensus is to form an opinion"

Tony, there is no scientific consensus that man's output of CO2 is going to bring about a disastrous future.

[PantsFan]

and of course Tony is immune from confirmation bias.

[Russ R.]

"Didn't say anything about Christy's methods."

Yeah... we noticed you had nothing to say about anything relevant.

But feel free to question other people's motivations, if that makes you feel better about yourself.

"Just wondering when Reason was gonna take a scientific approach to science reporting, or stick with its propagandistic method."

I distinctly recall Reason providing some pretty throrough reporting every time the IPCC has released a new report (or a summary for policymakers).

Is that not sufficiently scientific for you? What's your problem with journalists reporting all sides of a story?

[Tony]

What's your problem with journalists reporting all sides of a story?

Actually I have a really big problem with this. Because it usually devolves into reporting two sides regardless of which side has the evidence in its favor. And that's when it's not just reporting the side that lacks evidence because it accords with its ideological position.

[EscapedWestOfTheBigMuddy]

Actually I have a really big problem with this. Because it usually devolves into reporting two sides regardless of which side has the evidence in its favor. And that's when it's not just reporting the side that lacks evidence because it accords with its ideological position.

Ah ha! So you object to the endless reporting on the "hockey stick graph" becasue the groupthat published it won't give up their code, or even a detailed explanation of how they did their otlier removal and proxy bias adjustments. ANd when another group tried to follow what "recipe" ther did give the resulting code generated hockey sticks on null data. And then the original group would run their code on null data set to show that it did not...

[Tony]

? Hockey stick graph? You still stuck on that? Do you know anything about current climate science at all?

[SpongePaul]

IF you think about it, Plants control the climate, as far as climate is concerend they are the supreme life form. When its warm and rich in CO2 the plants thrive, which removes the co2 and produces o2. the abundance3 of plants making o2 help the animals. adding co2 and sequestering o2 the plante begins to warm as the animals use up the o2 the plants produce and turn it back into co2 the temp begins to drop,after a while if there are too many animals and not enough plants the co2 level goes up. err simple and prolly not 100 right, but gives you the idea eh!

[EscapedWestOfTheBigMuddy]

? Hockey stick graph? You still stuck on that? Do you know anything about current climate science at all?

In 2005 and 2006 I took a considerable stretch of time reading in climatology. It was slow going because that is out of my field, and really took a bite out of my work time.

I haven't tried to keep up.

When did you last read the literature, Tony?

The "hockey stick" graph remain relevant because:

* It that is really the climate behavior, it is diagnostic.

* At the time the proponents pushed it hard, and were not forthcoming about their methods, and if you don't pony up about what you did and why you are not doing science, and if you're not doing science you can't expect your thoughts to have that sciencey cachet.

* Large scale, long term computer modeling is hard, Tony. Really, really hard. And you can never have confidence without testing it against data, which is why good long term data are essential. Until there is consensus about how to handle proxy data sets there is no way to have confidence in the history needed to test the models. Without that and alleged consensus about what is happening next is built on shakey foundations.

But the question at hand was about the media reporting sides of scientific controversies that "lacks evidence because is accords with its ideological position". Much of the media likes climate change, because it makes a good story, so they latched onto the dramatic graph and showed it over and over again, even after the questions came up.

Did you object? Or does that only apply to people you disagree with?

[juris imprudent]

So Tony, max hats how about it - what is the optimal global temperature? What are your sources for that? Win me over with some evidence.

[Tony]

juris,

A good explanation that should answer your question:

Climatologists prefer to combine short-term weather records into long-term periods (typically 30 years) when they analyze climate, including global averages. Between 1961 and 1990, the annual average temperature for the globe was around 57.2?F (14.0?C), according to the World Meteorological Organization. According to estimates by the World Meteorological Organization, in 2008 that the global temperature was about 0.56?F (0.31?C) above that long-term average.
Why are global temperatures usually expressed this way-as a departure from normal, instead of a simple global temperature? One reason is that there are several different techniques for coming up with a global average, depending on how one accounts for temperatures above the data-sparse oceans and other poorly sampled regions.

Since there is no universally accepted definition for Earth's average temperature, several different groups around the world use slightly different methods for tracking the global average over time. The important point is that the trends that emerge from year to year and decade to decade are remarkably similar-more so than the averages themselves. This is why global warming is usually described in terms of anomalies (variations above and below the average for a baseline set of years) rather than in absolute temperature. A Web site from NASA's Goddard Institute for Space Studies goes into more detail on the topic of The Elusive Absolute Surface Air Temperature.

http://www.epa.gov/climatechange is a good place for information.

[TallDave]

I think you missed the biggest news: the wobble in Earth's orbit was confirmed as the major climactic influence, the one that controls the Ice Ages of the last few millions years.

Score another one for natural variation. Oh, and we're heading into the next Ice Age. Whether civilization can survive that is questionable.

Meanwhile, the signature of CO2-induced warming -- the mid-tropospheric hot spot -- doesn't exist. There is very little reason to think CO2 is driving temps in any meaningful fashion.

[TallDave]

No, that's why I have to rely on what the scientific consensus is to form an opinion

The scientific consensus says expert predictions have a very poor track record.

Glad to see you've ditched that unscientific global warming crowd.

[eb]

If I remember correctly, it was around the time that Hit and Run jumped on the Global Warming bandwagon that Hit and Run stopped being a serious blog.

[juris imprudent]

Tony, you might have noticed that although you quoted a lengthy bit, it did NOT answer my question. Not even one part.

Thanks for playing and be sure to collect your consolation prize on the way out.

[johnny john john]

The optimal global temperature is the temperature humans are most used to. If the temperature we got right now aint broke then don't change it!

Conservatism is a good rule of thumb, especially when you don't know what the fuck you're doing.

[Quiet Desperation]

If you want to know the harry details

Who is Harry and why does he have the details?

Can you tell how much of a gnat's fart I give about Global Warm- oops, I mean Climate Change?

Maybe Gaia just has PMS.

[hot trends]

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[ecommerce hosting]

It can't be accurate. I dont think soo...

[bm944]

The problem I have with all the global warming data presented is it is only a small snapshot of data. If you go back 2000 or 10,000 years the trends we see today are repeated. Previous temperature gains have been higher than we have seen in this century.
You have to look at the data not political science. Geological, historical records and ice core data are good indications of previous cycles but since the data is not collected using the same methodologies it can not be presented as hard scientific data. After looking at lots of different views on the cause of variations in temperatures, I think that the variations in solar activities vs. temperature changes seems to makes the most sense.