One of my oceanography lecturers is skeptical about climate change that can be attributed to humans producing greenhouse gases. I'm just a student, and don't like to get in any arguments with any of my lecturers, especially with exams coming up. But he does seem pretty on to it in class.

What does everyone think of this paper of his...

http://nzma.org.nz/journal/122-1305/3869/DeLange.pdf

The part where it says

"However, both approaches
indicate that the direct increase in temperature due to
an enhanced Greenhouse Effect is relatively small, and
positive feedback mechanisms are invoked to predict
higher temperature responses."

...sums up his stance on climate change.

Also in my notes it says
-Physics indicate doubling of CO2 may raise temperature by 0.8 +/- 0.4,
-less than 3% extra forcing,
-Computer models assume positive feedbacks amplify this. Computer models are predicting more warming than is occuring.
-Hundreds of independent studies show medieval warm period was 0.5C warmer than now and that the little ice age was -0.5C cooler than now.
- Long term climate is cooling towards next glacial


Personally, I don't know much about climate change and it has only been covered over two lectures in my this earth science paper I'm taking. But am interested to know more about it.

nimbus wrote:What does everyone think of this paper of his...

http://nzma.org.nz/journal/122-1305/3869/DeLange.pdf

I haven't read the whole thing. I'm a bit appalled by the lack of citations, and I'm shocked that a paragraph starts with "The discredited 'Hockey Stick' reconstruction..."

The part where it says

"However, both approaches
indicate that the direct increase in temperature due to
an enhanced Greenhouse Effect is relatively small, and
positive feedback mechanisms are invoked to predict
higher temperature responses."

...sums up his stance on climate change.

The Earth's climate has drastically shifted over geologic time. On the 10- to 100 thousand year timescale, these changes are attributable to orbital cycles that slightly alter the distance between the Earth and the sun. These changes are relatively small, yet the impacts are not. Your instructor's instincts are fine; tenacity to actively seek research to better understand apparent contradiction, however, is lacking.

Also in my notes it says
-Physics indicate doubling of CO2 may raise temperature by 0.8 +/- 0.4,
-less than 3% extra forcing,

This appears to be under the assumption that essentially no feedbacks amplify effect. This assumption is not supported by paleoclimatic data. Paleoclimatic data indicate CO2 and temperature are inseparable over geologic timescales.

-Computer models assume positive feedbacks amplify this. Computer models are predicting more warming than is occuring.

Positive feedbacks are not based on assumptions. They are based on empirical data. Temperatures have been well within common prediction. Moreover, recent data are suggesting many of IPCC's last projections may be mild.

-Hundreds of independent studies show medieval warm period was 0.5C warmer than now and that the little ice age was -0.5C cooler than now.

1. It's been far hotter in the past many times.

2. Paleoclimatic data indicate the Medieval Warm Period was regional (e.g., http://www.meteo.psu.edu/~mann/shared/a ... ence09.pdf).

- Long term climate is cooling towards next glacial

It was. Likely not for some time now.

Personally, I don't know much about climate change and it has only been covered over two lectures in my this earth science paper I'm taking. But am interested to know more about it.

First, understand that your lecturer is out of his/her area of expertise. Oceanographers are not climatologists. I'm a geologist. I am not a climatologist. We who are beyond our areas of expertise should try to best understand expert consensus. Multiple studies indicate a ~ 97% consensus among active climate researchers. That should be your starting point. It should be my starting point. It should be your lecturer's starting point.

I would suggest browsing some abstracts. You can access a number of articles for free at the Journal of Science. A number of Hansen's articles are also freely available. Assess the peer-reviewed material to better understand the subject. Avoid non-scientist and other blowhard bloggers, and avoid those who publish beyond their fields in relatively unknown journals.

I'm short on time, and I'm beyond my area of expertise, but I find climate change fascinating. If you have any questions, please don't hesitate to ask!

Just had a skim, and noticed on p. 207 he asserts that "Typically, warming at the surface is associated with an increase in salinity, while cooling is associated with a decrease in salinity." This is not completely correct, as deep water formation in polar regions through either wind evaporation or ice formation (brine exclusion) results in more saline and very cold waters, which then flow along the sea floor to great depths. The currents generated by this cold deep water are orders of magnitude greater than those formed by warm deep water formation.

Methane has a much larger effect than CO2, and it is not being removed fast enough:-

http://globalwarming.solveyourproblem.c ... fect.shtml

http://en.wikipedia.org/wiki/Methane

Humans produce about 2 liters of fart/day. There are 6.8 billion humans, so people worldwide produce about 14,000 billion liters per day of methane and other greenhouse gases. Typical predator prey ratios for homeotherms is at 1/100, so farm animals would produce at least 100 times that, probably much more, because I don't know how much cows fart and belch, but it is probably at least 10 times human output. methane persists for about 10 years.

As the climate warms, more methane is released from marches etc that were previously under snow or permafrost lands. Irrational climate skeptics are dickheads, because if their message succeeds, they will kill us all. Stoopid bastards.
A lot of this [so-called] 'reasonable skepticism" is driven by the Christian right, who [even if they believe in global warming, and many don't] reckon the Jeebus zombie raptor will come down and sort it out for them. The other big misinformers are the fossil fuels industries, who have a vested interest. George Bush came from Big Texas Oil and the religious right...I rest my case.

Weaver wrote:While it's true that methane has a greater effect than CO2 for a given volume of gas, and that it is currently building in the atmosphere, CO2 has a much greater total volume (and thus actual effect) and much longer lifespan in the atmosphere.

The whole farting thing is part of the disinformation campaign from denialists - they like to claim that increased use of cattle could be the "real" cause of global warming - when in fact a recent paper shows the US dairy industry accounts for about 2% of US greenhouse gas emissions. Other farts can be infered to have a minor, though notable, effect.

Yup, I know. I was also trying to be partly humerus. Carbon dixoide can be more easily sequestered underground, or by halting/reversing the destruction of aquatic and terrestrial photosynthetic autotrophs.

Giggles!

OMGturt1es wrote:
First, understand that your lecturer is out of his/her area of expertise. Oceanographers are not climatologists. I'm a geologist. I am not a climatologist. We who are beyond our areas of expertise should try to best understand expert consensus. Multiple studies indicate a ~ 97% consensus among active climate researchers. That should be your starting point. It should be my starting point. It should be your lecturer's starting point.

Thanks for pointing out the errors. I had heard about the large consensus amount climate researchers which is why I was shocked when I was being taught the opposite in an earth science class!

Although, my lecturer mentioned in class that he was listed as one of approximately 3000 “scientists” who agreed that there was a discernable human influence on climate in an IPCC report but he was never asked if he supported this view by any survey, but his name was added to the list. See link... http://climaterealists.com/index.php?id=3477

Weaver wrote:
There's an interesting topic about computations of just how much effect the CO2 has. Water vapor accounts for 75% of greenhouse effect, CO2 for about 20%, and other greenhouse gasses 5%. The 25% accounted for by greenhouse gasses results in 80% of the radiative forcing.

Bottom line - CO2 is THE cause of global warming, and the CO2 in the atmosphere now is due to human releases (due to industrialization). The current atmospheric levels of CO2 are about 30% higher than have ever occured due to natural causes - and they are still rising, and will continue rising for a long time.

Wikipedia seem to have different percentages than the ones you listed. It says that
36 – 72 % Contribution for water vapour
9-26% contribution for Carbon dioxide
4 – 9 % for Methane
3 – 7 % for Ozone

It then goes on to note that it is not possible to state that a certain gas causes an exact percentage of the greenhouse effect. This is because some of the gases absorb and emit radiation at the same frequencies as others, so that the total greenhouse effect is not simply the sum of the influence of each gas. The higher ends of the ranges quoted are for each gas alone; the lower ends account for overlaps with the other gases.

You say that "current atmospheric levels of CO2 are about 30% higher than have ever occured due to natural causes."

Really? I mean I know that CO2 has been increasing over over the last 100 years but (correct me if I'm wrong) I had heard that CO2 levels have at times in the earth's history been alot higher due to natural causes than they are today. But the earth didn't burn to a frazzle back then only because solar output from the sun was not as great as it is today, but if we had those really high CO2 levels today - in combination with what solar irradiance is today - then we would boil.

Darwinsbulldog wrote:
A lot of this [so-called] 'reasonable skepticism" is driven by the Christian right, who [even if they believe in global warming, and many don't] reckon the Jeebus zombie raptor will come down and sort it out for them. The other big misinformers are the fossil fuels industries, who have a vested interest. George Bush came from Big Texas Oil and the religious right...I rest my case.

You are probably right.. but I don't like you're arguing style. Yes, many skeptics of global warming are biased but not all are. And even if someone is biased due to a religious or political belief it does not necessarily mean that they are wrong about climate change. In this case, however, my skeptical lecturer is neither a christian nor employed by an oil company.

Also it works both ways. For instance, on the other side they say things like "global warming is being exaggerated by the greenies and the liberals because the greens want more money for their causes and the liberals want more taxes on the rich, green taxes etc..."

Both sides can claim that the other is biased and has vested interests. And this makes it harder for the public to know what is actually going on.

Nimbus wrote:-

You are probably right.. but I don't like you're arguing style. Yes, many skeptics of global warming are biased but not all are. And even if someone is biased due to a religious or political belief it does not necessarily mean that they are wrong about climate change. In this case, however, my skeptical lecturer is neither a christian nor employed by an oil company.

Well, it sort of does actually. it is very unlikely that someone who starts of with a firm belief is going to weigh the evidence dispassionately. Confirmation bias. Say a man is sexist. He will tend to ignore good women drivers, and just notice the bad ones. Yes, it is possible that a fundi Christian might accept evolution and reject creationism, but not likely.

Also it works both ways. For instance, on the other side they say things like "global warming is being exaggerated by the greenies and the liberals because the greens want more money for their causes and the liberals want more taxes on the rich, green taxes etc..."

Yes, of course. But either way, it does not change the facts. If we are in deep environmental shit [which we are-not just climate change, but species extinction, overpopn, pollution etc.] then the rationalist who is paying attention to the facts should cautiously side with the greenies. Some greenies do go overboard of course...wanting to save teddy bears or whatever when krill might be more important.

Both sides can claim that the other is biased and has vested interests. And this makes it harder for the public to know what is actually going on.

But does each claim have equal value? No! Furthermore, conservatives [especially religious ones] tend to deny any science that does not jive with their beliefs...there is a correlation between creationism/ID and skepticism about climate change. As for [energy/resource] business, it is mainly driven by what the share price is this second.
So as soon as you get folks spin-doctoring the truth, and rejecting the science, then there is trouble on many fronts. Good education is the antidote.

Weaver wrote:While it's true that methane has a greater effect than CO2 for a given volume of gas, and that it is currently building in the atmosphere, CO2 has a much greater total volume (and thus actual effect) and much longer lifespan in the atmosphere.

The whole farting thing is part of the disinformation campaign from denialists - they like to claim that increased use of cattle could be the "real" cause of global warming - when in fact a recent paper shows the US dairy industry accounts for about 2% of US greenhouse gas emissions. Other farts can be infered to have a minor, though notable, effect.

Apparently it's burps, not farts, that contribute the most from cows.

Weaver wrote:
Yeah, why trust recent scientific papers when you have Wikipedia, right?

The latest model takes into account what the percentages of greenhouse gas radiative forcing are, including the various absorption frequencies and the overlap.

And yes, current levels are higher than have ever been seen before. Ice core samples date back over 150,000 years - many, many cycles of normal systems. The highest natural concentration of atmospheric CO2 in the historical record was 290 parts per million (ppm). Current atmospheric levels are at 390ppm and rising - I would be surprised if it tops out at 500ppm, possibly much higher.

Wikipedia can have errors and often is not up to date, but it's a pretty good place to start when researching a topic. What is this latest model that you are referring to? A weblink would help.

I still maintain that it is not correct to say that CO2 levels have never been this high before. It all depends on the time scale you choose to use. See the link below for evidence of the high variations in CO2 over the earths history.
http://www.geocraft.com/WVFossils/Carbo ... imate.html

Ofcourse just because CO2 levels may have been far higher in the past due to natural causes does not mean that today our increasing level of CO2 and other greenhouse gases are not being driven up by the clearing of forests and burning of fossil fuels and so on. The big question is what effect is this having on global temperature?

nimbus wrote:

Really? I mean I know that CO2 has been increasing over over the last 100 years but (correct me if I'm wrong) I had heard that CO2 levels have at times in the earth's history been alot higher due to natural causes than they are today. But the earth didn't burn to a frazzle back then only because solar output from the sun was not as great as it is today, but if we had those really high CO2 levels today - in combination with what solar irradiance is today - then we would boil.

No we wouldn't. Water boils at 100 degrees, and the hottest natural temperature ever recorded anywhere on planet earth was 57.8 degrees, in Libya. Climate change worst case scenarios don't even hit 8 degrees, on average temperatures.

It changes the profile for life. That's not good for species that adapted to a certain profile (humanity...). But it doesn't 'kill everything.' Just another extinction event.

The big question is what effect is this having on global temperature?

It's not a "big question" - it's a well answered question. And has been for a long time..

It's getting warmer
We're responsible due to release of fossil Carbon from using fossil fuels.
Learn some science

Background/history
http://www.aip.org/history/climate/summary.htm

and perhaps ask yourself if you think its still a "big question" ...why the fossil fuel companies own scientiests called it "irrefutable" 15 years ago.
and the fossil fuel companies knew this in the mid 90s..

Industry Ignored Its Scientists on Climate

By ANDREW C. REVKINPublished: April 23, 2009

For more than a decade the Global Climate Coalition, a group representing industries with profits tied to fossil fuels, led an aggressive lobbying and public relations campaign against the idea that emissions of heat-trapping gases could lead to global warming.

“The role of greenhouse gases in climate change is not well understood,” the coalition said in a scientific “backgrounder” provided to lawmakers and journalists through the early 1990s, adding that “scientists differ” on the issue.

But a document filed in a federal lawsuit demonstrates that even as the coalition worked to sway opinion, its own scientific and technical experts were advising that the science backing the role of greenhouse gases in global warming could not be refuted.

This is the reality

Here is what Gammon had to say concerning links between humans and climate change.

This is like asking, ‘Is the moon round?’ or ‘Does smoking cause cancer?’ We’re at a point now where there is no responsible position stating that humans are not responsible for climate change. That is just not where the science is.…For a long time, for at least five years and probably 10 years, the international scientific community has been very clear.”

In case there is any doubt, Gammon went on:
This is not the balance-of-evidence argument for a civil lawsuit; this is the criminal standard, beyond a reasonable doubt We’ve been there for a long time and I think the media has really not presented that to the public.”

Dr. Richard H. Gammon
Professor of Chemistry and Oceanography*
Adjunct Professor Atmospheric Sciences, University of Washington

GreyICE wrote:

nimbus wrote:

Really? I mean I know that CO2 has been increasing over over the last 100 years but (correct me if I'm wrong) I had heard that CO2 levels have at times in the earth's history been alot higher due to natural causes than they are today. But the earth didn't burn to a frazzle back then only because solar output from the sun was not as great as it is today, but if we had those really high CO2 levels today - in combination with what solar irradiance is today - then we would boil.

No we wouldn't. Water boils at 100 degrees, and the hottest natural temperature ever recorded anywhere on planet earth was 57.8 degrees, in Libya. Climate change worst case scenarios don't even hit 8 degrees, on average temperatures.

It changes the profile for life. That's not good for species that adapted to a certain profile (humanity...). But it doesn't 'kill everything.' Just another extinction event.

I know I used the word 'boil' but I didn't literally mean it. Just an expression for saying it would be really hot.

GreyICE wrote:

nimbus wrote:

Really? I mean I know that CO2 has been increasing over over the last 100 years but (correct me if I'm wrong) I had heard that CO2 levels have at times in the earth's history been alot higher due to natural causes than they are today. But the earth didn't burn to a frazzle back then only because solar output from the sun was not as great as it is today, but if we had those really high CO2 levels today - in combination with what solar irradiance is today - then we would boil.

No we wouldn't. Water boils at 100 degrees, and the hottest natural temperature ever recorded anywhere on planet earth was 57.8 degrees, in Libya. Climate change worst case scenarios don't even hit 8 degrees, on average temperatures.

Remember though that the 57.8 degrees is temperature in the shade. The temperature in the sun will be significantly above that, potentially reaching boiling point. Even ignoring that, evaporation already occurs at well below 100 degrees air temperature. Of course rain brings it all back down again.

In this context I found the recent research by NASA interesting, that distinguishes water-vapour from other greenhouse gases, where the latter are "non-condensing" (http://www.nasa.gov/topics/earth/featur ... ature.html). Basically, if water-vapour (always touted as the most important greenhouse gas) was the only greenhouse gas, then it would very quickly condense out of the atmosphere, and the earth would plunge into a permanent snoball earth state.

It changes the profile for life. That's not good for species that adapted to a certain profile (humanity...). But it doesn't 'kill everything.' Just another extinction event.

Rats and cockroaches and seagulls and tardigrades, oh my.

You'd think humans are generalist enough to survive an extinction level event. Certainly not with any quality of life.

Of course, that's how small a percentage of the atmosphere? Isn't debating 290 v. 390 quibbling over tenths of a percent of the atmosphere? Hmm... Just wondering.