A Note: Global Warming Threads

[Believe]

To be clear, the way this was done was to group people by the number of papers published, the cut off number was 20 and all they were agreeing to was this rather modest statement:



To paraphrase that statement using actual numbers and see why it's not surprising at all that most people agree with it:



I agree with that statement, so I'd be in the CE group as well.

Yet I'm very skeptical of much of the IPCC modeling for the climate of the coming century since it is based on totally unrealistic scenarios used as input to very hot models to create an upper range that is not credible, but none the less are used as input to other papers to project the "results" of global warming in the most alarming method possible.

So when appropriate, I can be a skeptic.

So the point is, one can be skeptical of some of the methods in the field and yet not be in denial of anything.

Polarizing the debate by assigning labels and putting people in imagined pigeon holes is not productive.

Stick to the actual science/methods please.

Your right to be sceptical about any specific future claims made by anyone at this point, and about claims being made about the current rise in tempuratures. The truth is that the world is too big with too many variables to model with that kind of precision (weather man anyone?).

However, here are the facts.

1. CO2 absorbes more heat from the sun then the standard composition of air.

2. CO2 levels are higher (from us) then they have ever been in any time that we have any data on, and they just keep going up.

3. Eventually, something has to break and earth will begin to heat up. Exactly when, at what concentration, and how much per unit rise in concentration it will heat up is currently not accurately known (I.E. recent revelations about the oceans soaking up more heat than expected, thing like this may keep happening because again there are just too many variables).

The phenomenon is real, but sensational statements from the media and scientists involved that can be easily disproven, or called into question have created a distrust about the whole thing. Not to mention the climate gate crap. If they had just stuck to the facts they there could be no argument (cuz there facts you know, not that wouldn't stop some).

It is inevitable if we continue on this course. I am quite sure however, that with all the distrust bad shit will have to happen (rising oceans destroying major cities and whatnot) that can be directly linked to global warming before any decisisive action is taken by the world as a whole.

One can only hope that by then, it is not too late to do anything about it.

 

[adoucette]

Actually CO2 levels are at historically very low levels, as is the temperature of the Globe.

Or consider this chart.

All the time that the temps are running from -2 to -8C (which is by far, MOST of the last half million years) the world is covered in a layer of thick Ice, often reaching down past Chicago, and the levels of the ocean's plummet by up to 120 meters.

Note, while it's not obvious when comparing these two charts, do note that the RISE in global temperature in these charts PRECEEDS the rise in CO2 by roughly 500 years, and the FALL in temps is likewise not prevented by high levels of CO2, but falls after the temp falls.

And the world looked like this:

 

[iceaura]

The phenomenon is real, but sensational statements from the media and scientists involved that can be easily disproven, or called into question have created a distrust about the whole thing. Not to mention the climate gate crap. If they had just stuck to the facts they there could be no argument

They, the scientists involved, did just stick to the facts, and nothing they stated has been disproven easily or otherwise.

That does not appear to have been enough.

 

[billvon]

NOTE #1 : According to the most recent data available there are 11,194,445 miles of paved roads in the world. Roads convert sunlight into heat, that is a LOT of heat.

Let's say roads average 20 feet across. That's 4500 square miles of road, or .00225% of the earth's surface. And keep in mind that seawater absorbs more heat than old asphalt (albedos of .08 and .12 respectively) and there's a lot of seawater.

Approximately 85.27 million gallons of fuel (gasoline, diesel, and oil) is burned worldwide in 24 hours. (The world's daily supply of fuel (approximately 85.93 million gallons) barely covers the demand. (That's why its so expensive)) That's a lot of heat produced by internal combustion engines, is it not?!

Gasoline contains about 36kwhr of thermal energy per gallon. So that's about 127 million kilowatts of heat generated by gasoline burning.

Now let's compare that to the forcing by the CO2 that we've added to the atmosphere, which is about 1.6 watts per square meter. The surface of the planet is 510 000 000 sq km or 510 000 000 000 000 sq m. CO2 forcing affects radiated heat, so it affects the entire planet. That's 816 000 000 000 kilowatts of additional heat.

To put it another way, the heat generated by burning the fuel is 0.000015% of the heat due to the extra CO2.

Just sit back, relax, and accept these obvious facts as to why the Earth is heating up... (possibly combined with the Earths natural trends?? )

Well, less obvious when you do the math.

 

[GlobalSkeptic]

Actually CO2 levels are at historically very low levels, as is the temperature of the Globe.

Don't let facts get in the way of a good argument. Great post.

 

[Manish]

We had an Ice Age in the past, and there were no industries then to trigger global warming with carbon and other emissions as is claimed by the environmentalists or even by the governments. I strongly believe that our planet has its own reasons for climate change and we humans can't own it entirely with our limited knowledge !!

 

[Trippy]

We had an Ice Age in the past, and there were no industries then to trigger global warming with carbon and other emissions as is claimed by the environmentalists or even by the governments.

Strawman hypothesis.

The claim that is made is that carbon causes warming,that we're causing the observed increase in atmospheric CO[sub]2[/sub] and that we are, as a direct consequence of this, causing warming in the environment.

That greenhouse gasses cause warming is trivially demonstrable.
That carbon dioxide is a greenhouse gas is equally trivially demonstrable.

The first demonstration uses physics such as greybody and blackbody radiation, combined with the inverse square law and empirical measurements.
The second demonstration can be done with simple harmonic motion, is backed up by quantum mechanics, and has been confirmed by empirical measurements.

The only question that is then left is what effects this excess heat energy will have on the environment.

The claim that "there were no industries then to trigger global warming with carbon and other emissions as is claimed by the environmentalists or even by the governments" is incorrect antiscience disinformation. What is "claimed by the environmentalists" is that previous episodes of climate change were driven by various naturally occuring factors:

-Natural variations in atmospheric chemistry: There are a number of ways that atmospheric chemistry can vary naturally. The uplift of the Tibetan and Colorado plateaus, and their subsequent erosion, for example, is thought to be responsible for much of the cooling during the cenozoic.
-Variations in Orbital Parameters: These are the milankovich cycles. Variations in elipticity, axial tilt, and so on lead to variations in the amount of insolation, which in turn changes climate forcings, warming or cooling the climate. Contrary to 'popular' opinion, environmentalists do actually believe that the sun drives climate. That's the whole point, in fact.
-Variations in Solar output: Contrary to popular belief, solar variability part of climate modeling.
-Variations in Geography: Things like equatorial supercontinents, land locked polar seas, and polar continents are all known (from the geological record) to be drivers of long term climate change. Basically, anything that affects the transport of heat energy from the equator to the oceans. For example, the opening of the drake passage and the establishment of the antarctic circumpolar current is one of the factors believed to have contributed to or even accelerated the glaciation of Antarctica.

 

[Aqueous Id]

Trippy/billvon,

Excellent posts as usual. I'm not sure I've ever seen either argument put together like this. Very convincing.

 

[arfa brane]

What's wrong with this statement?

Actually CO2 levels are at historically very low levels, as is the temperature of the Globe.

i) It uses the word "historically" without qualifying it. Humans and other mammals are living in a climate which is "historically" low-temperature.
ii) It looks like it's suggesting that everything is normal, nothing to worry about.
But mammals, and certainly humans, don't have the same history; mammals are adapted to this relatively low-temperature and low-CO2 climate.
Then this:

Note, while it's not obvious when comparing these two charts, do note that the RISE in global temperature in these charts PRECEEDS the rise in CO2 by roughly 500 years, and the FALL in temps is likewise not prevented by high levels of CO2, but falls after the temp falls.

Says nothing useful about the RISE in global temperatures being observed today and whether humans are responsible. The charts show natural variations in CO2 and temperature. It isn't true either, that historically temperature always preceded CO2 rises. And it isn't true that when these changes occurred in the past, the planet was dominated by a species that was very efficient at finding and burning fuel, at cutting down trees and making large-scale changes to the environment.

And it isn't true that the historical warming mechanisms are fully understood. Nor is it true that the IPCC has all the answers.
Since there is a "lot" of uncertainty it just isn't very intelligent to think "nothing much will happen" over the next century. In fact, we don't know enough to say.

Proclaiming "the sea won't rise by more than 1 metre in the next 100 years", is really just guessing, I would estimate the uncertainty in that guess to be at least 100%.
Note that rising sealevels is only one effect of warming, another is increased levels of H2O in the atmosphere, so more precipitation, more floods, wilder weather because of the increased transport of heat (because of the extra H20).

My take is that humans (or some of us) are intelligent enough to understand the "dangers", but also complacent enough to not do anything. It is quite unlikely that we will collectively mitigate warming by drastically reducing our carbon output. We aren't that "intelligent".
So the world is going to change, maybe not that noticeably for most people alive today, but then again, there is a large uncertainty.
I know, I know, we like to be optimistic; perhaps some new technology will save the planet? Well, "historically", human technology hasn't had a good record there; I can't think of any example that we've been using for any decent amount of time that qualifies as a planet-saver, how about you?

 

[Billy T]

".. The Arctic has lost more sea ice this year than at any time since satellite records began in 1979, Nasa says. Scientists involved in the calculations say it is part of a fundamental change.

What is more, sea ice normally reaches its low point in September so it is thought likely that this year's melt will continue to grow. Nasa says the extent of sea ice was 1.58m sq miles (410m sq km) compared with a previous low of 1.61m sq miles (4.17m sq km) on 18 September 2007.

The sea ice cap grows during the cold Arctic winters and shrinks when temperatures climb again, but over the last three decades, satellites have observed a 13% decline per decade in the summertime minimum. The thickness of the sea ice is also declining, so overall the ice volume has fallen far - although estimates vary about the actual figure.

Joey Comiso, senior research scientist at Nasa's Goddard Space Flight Center, said this year's ice retreat was caused by previous warm years reducing the amount of perennial ice - which is more resistant to melting. It's created a self-reinforcing trend. Professor Peter Wadhams, from Cambridge University, told BBC News: "A number of scientists who have actually been working with sea ice measurement had predicted some years ago that the retreat would accelerate and that the summer Arctic would become ice-free by 2015 or 2016. .."

billy T comment: This black cloud has a silver lining, especially for Russian exports to China. Also self accelerating, it would seem to me to be the great reduction in summer albedo - more sunlight heating with near black water instead of white snow.

 

[Trippy]

billy T comment: This black cloud has a silver lining, especially for Russian exports to China. Also self accelerating, it would seem to me to be the great reduction in summer albedo - more sunlight heating with near black water instead of white snow.

Billy... You do know that the albedo of water is latitude dependent, right?

 

[Billy T]

Billy... You do know that the albedo of water is latitude dependent, right?

Yes. It is mainly a function of the angle of incidence of the photon striking the water surface and that can be much more nearly normal due to waves and even ripples too small for humans to see. Artic regions often have winds so it is much more complex than just a latitude function. The low gross angle of incidence at high latitude means rarely will the photon hit the low point of the ripple (or wave) but mainly hit on the sides of the wave shape.

This is the same reason any rough surface has lower albedo than same material with an atomically smooth surface does. Or crudely: rough surfaces are blacker than smooth surfaces for non-normal gross incidence as some of the photons do have near normal incidence on a rough surface. Quite possibly this is why the water in photo of post 850 looks so black.

 

[Trippy]

Yes. It is mainly a function of the angle of incidence of the photon striking the water surface and that can be much more nearly normal due to waves and even ripples too small for humans to see. Artic regions often have winds so it is much more complex than just a latitude function. The low gross angle of incidence at high latitude means rarely will the photon hit the low point of the ripple (or wave) but mainly hit on the sides of the wave shape.

This is the same reason any rough surface has lower albedo than same material with an atomically smooth surface does. Or crudely: rough surfaces are blacker than smooth surfaces for non-normal gross incidence as some of the photons do have near normal incidence on a rough surface. Quite possibly this is why the water in photo of post 850 looks so black.

No, Billy. All the information you need for interpreting that photo is in the photo itself.

If you examine the photo carefully:

You will see that the water is, in fact, quite calm.

We can infer this from the fact that we can observe specular reflection of the ice cliffs in the background. If we examine the photo closely, we can see that the water is reflecting the colour of the sky almost through the entire photo - almost but not quite, because when the angle subtended to the water by the rays that reach the camera exceeds a certain value, the water is no longer capable of specular reflection, except off, for example, ripples in the surface.

The water looks the way it does because the water is reflecting the sky up until the line to the camera reaches some critical angle and the camera can no longer see the reflection.

 

[Billy T]

... If you examine the photo carefully... You will see that the water is, in fact, quite calm. ...

Yes at least on the scale of the film resolution, Perhaps even on the scale of human resolution, if you were there, but not very likely to be flat on the scale that counts for abledo determination - I.e. free of ripples on the scale of solar radiation wavelengths.

 

[Billy T]

"... Study leader Jemima Wadham, from Bristol University, said: "This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions.

"Our laboratory experiments tell us that these sub-ice environments are also biologically active, meaning that this organic carbon is probably being metabolised to carbon dioxide and methane gas by microbes."

They estimate that there could be hundreds of billions of tonnes of carbon stored in methane reservoirs under the ice sheet.

The authors say that the predicted shallow depth of these methane reserves means that they could be destabilised by climate change, and might act as a positive feedback on global warming.

"Just like in sub-seafloor sediments, it is cold and pressures are high which are important conditions for methane hydrate formation."

In their Nature paper, the authors comment that their "findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget". ..."

I doubt that the pressure is high enough to form methane hydrates under floating sea ice, except possibly below very large icebergs, but under the Greenland ice sheet, which at points is more than a mile thick, it surely is. As paper has been published by Nature one of the two most important general science journals in the world, their result must be taken seriously.

The following is not new, but seems to be gaining support again:

"... Scientists have identified thousands of sites in the Arctic where methane that has been stored for many millennia is bubbling into the atmosphere. The methane has been trapped by ice, but is able to escape as the ice melts. Writing in the journal Nature Geoscience, the researchers say this ancient gas could have a significant impact on climate change. ..."

 

[Billy T]

{Post 850 without the photos}... This black cloud {great Arctic sea ice reduction} has a silver lining, especially for Russian exports to China. Also self accelerating, it would seem to me to be the great reduction in summer albedo - more sunlight heating with near black water instead of white snow.

Here just released by BBC is what I was stating in post 850 but now more quantative:

"... White ice reflects more sunlight than open water, ... Melting of white Arctic ice, currently at its lowest level in recent history, is causing more absorption. Prof Wadhams calculates that this increased absorption of the sun's rays is "the equivalent of about 20 years of additional CO2 being added by man." The Cambridge University expert says that the Arctic ice cap is "heading for oblivion". ..."

 

[Trippy]

Here just released by BBC is what I was stating in post 850 but now more quantative:

Why are you still trying to argue this point Billy? Nothing in that article contradicts anything that I have actually said, if you've taken the time to understand what I'm saying instead of just reacting to it.

Here's what you said:

more sunlight heating with near black water instead of white snow.

To which I replied:

Billy... You do know that the albedo of water is latitude dependent, right?

According to peer reviewed and published literature, the albedo of the ocean varies between 0.01 and 0.4, and as well as being dependent on the angle of incidence, is also dependent on wavelength, aerosol optical depth (the effect of which is angle dependent), wind speed, and chlorophyl loading.

Snow, on the other hand, has an albedo in the vicinity of 0.8-0.9. So yes, when your albedo drops from 0.9 to 0.4 you're going to get increased warming, and at no stage have I suggested otherwise (nor is it reasonable to infer that suggestion from anything I have said).

This, however:

Is not, "Nearly black" (Desert sand has an albedo of 0.4)

This, however is:

(Fresh Asphalt has an albedo of 0.01).

And yes, I'm aware that there are any number of sources that you will be able to cite that state that the ocean has an albedo of 0.01 to 0.1, however, the figure of 0.4 is empericly measured, but was only published in 2004.

And so, I stand by my assertion that your statement "...more sunlight heating with near black water instead of white snow..." is wrong, because the water in the polar regions, due to the low incidence angle, is not properly characterized as "Nearly black", and my statement "You do know that the albedo of water is latitude dependent, right?" Nor anything I have said in that contradicts the assertion that melting in the polar regions will cause warming.

Are we clear? Or do you want to keep flogging a dead horse?

 

[Billy T]

... do you want to keep flogging a dead horse?

No. Your long post is quite enough flogging, especially as in reply to your asking me if I knew about the latitude dependance, I said "Yes" and pointed out that what really matters is the angle of incidence of the light on the water surface and even tiny ripples change that from the gross latitude effect. I.e. even at the North Pole, with waves, some photons are nearly normally incident on the surface and they have very high probability of being absorbed. If, however, the wave are "rolling over" and making "white caps" that can boost the albedo back up.

Post 855, was not to argue on what we basically agree on, but just to note that Cambridge Un. prof had just given a convenient quantative comparison (Change to open arctic water is like 20 years of man´s CO2 release.) and clearly stated (as I implied with my comment that there was a "silver lining" for Russian shipping to China) that the arctic would be ice free in the not distant future.

 

[Buddha12]

As George Carlin says about global warming....

http://www.youtube.com/watch?v=eGOBm2J4tn0&feature=player_detailpage

 

[wellwisher]

If you want to see a major source of natural CO2, look at this video from NASA; Fire and Smoke. It is based on 10 years of collecting fire data world wide from space.
[video]http://www.nasa.gov/multimedia/videogallery/index.html?collection_id=72681&media_id=116635311[/video]