Climate Change Denial, Anyone?

Why? What makes you think CO2 sinks are capable of dealing with current emission levels?

Well, according to Hansen et al (2013) the ‘airborne fraction’ of human CO2 has been decreasing. The airborne fraction is the amount of human CO2 left in the atmosphere after absorption by sinks. I should state that I think the airborne fraction calculations are wrong, but I won’t go into my reasons for thinking that. If we accept it for argument’s sake we can see that the airborne fraction has been decreasing as our emissions have been increasing, which would imply that they are ‘capable of dealing with current emission levels’. As a general rule, the more CO2 there is in the atmosphere waiting to be absorbed by the oceans, the more partial pressure it will exert upon the ocean surface and the faster it will be absorbed. This could be why the airborne fraction is decreasing. As our emissions increase, CO2 gets forced down to the oceans at a faster rate.

You say that CO2 forcing is not saturated then you use the argument that it is.

But I have not argued that the ‘CO2 forcing is saturated’. The calculations by Archibald (2006) show that it is essentially saturated, but those calculations are beyond my ken. If it were completely saturated if would probably be having no measurable warming effect, but we know that it is — to the tune of about 0.0091 W/m2 per 1ppmv at the surface.

But if the question is the relative contribution of CO2 to temperatures the sensitivity value is not relevant to the claim that CO2 only provides 0.01º out of 0.8ºC.

Well, we know that CO2 is contributing about 10% to the overall trend in back-radiation at the surface, assuming the measurements by Feldman are correct. So that means 90% of the surface warming is a result of something else. I think clouds are providing the largest warming. The paper referenced above showed that global cloud cover had decreased by about 1.56% since 1970 which would give about 3 W/m2 of extra forcing at the surface according to the Reed (1977) formula and that would account for most of the warming (assuming a general decrease). The IPCC are still quite uncertain when it comes to clouds. In AR5 (2013) the IPCC say that ‘Clouds continue to contribute the largest uncertainty to estimates and interpretations of the Earth’s changing energy budget’. Could the IPCC have possibly underestimated the warming from clouds?

Here are two studies regarding clouds:

The reduction in total cloud-cover of 6.8% [between 1984−2009] means that 5.4 W/m2 (6.8% of 79) is no longer being reflected but acts instead as an extra forcing into the atmosphere… To put this [5.4 W/m2 of solar radiative forcing via cloud-cover reduction between 1984−2009] into context, the IPCC Fifth Assessment Report… states that the total anthropogenic radiative forcing for 2011 relative to 1750 is 2.29 W/m2 for all greenhouse gases and for carbon dioxide alone is 1.68 W/m2. The increase in radiative forcing caused by the reduction in total cloud-cover over 10 years is therefore more than double the IPCC’s estimated radiative forcing for all greenhouse gases and more than three times greater than the forcing by carbon dioxide alone [from 1750 to present]. (Source)

Traditionally, the Earth’s reflectance has been assumed to be roughly constant, but large decadal variability, not reproduced by current climate models, has been reported lately from a variety of sources. There is a consistent picture among all data-sets [that] Earth’s albedo has decreased [from] 1985-2000. The amplitude of this decrease ranges from 2-3 W/m2 to 6-7 W/m2 but any value inside these ranges is climatologically significant. (Source)

You are ignoring the influence of that warming on water vapour concentrations and other forcing factors.

According to NASA ‘The atmosphere responds very fast to water vapour feedback’ and Hansen et al (2008) calls water vapour a ‘Fast Feedback’. Apparently a fast feedback is a feedback that takes ‘hours or years, whereas one that takes place over decades or centuries is called a slow feedback’. So, the 0.16C should include the water vapour feedback. The warming from water vapour would be lagging the warming from CO2 by less than a decade. So the water vapour feedback warming over the last decade (2005 to 2015) would have been in response to the CO2 increase from 1995 to 2005, which was about 20ppmv.

The airborne fraction is the amount of human CO2 left in the atmosphere after absorption by sinks.

That should read, ‘the fraction of human CO2’ left in the atmosphere. Decreased from 60% to around 50%.

a reply to: Nathan-D

Do you have a source to back up your claim?

Even if you are correct, and CO2 emissions have not increased, we will still see and increase of CO2 because the natural sinks cannot sink the excess CO2. This may mean(if you a correct about anthropogenic CO2 sources not increasing) that the rate of the CO2 increase may lessen, this still means we will see rising CO2 levels for the rest of our lives and further.

a reply to: jrod

I came across a new article in Nature that seems to be putting a stake in the heart of the Catastrophic Anthropogenic Global Warming once and for all

www.sciencedaily.com...

Now scientists of the GEOMAR Helmholtz Centre for Ocean Research Kiel, together with a colleague from Bergen (Norway), were able to demonstrate for the first time that natural fluctuations in water temperatures of the Pacific -- which occur on decadal timescales -- are directly related to the temperature of the tropical tropopause. "It has long been thought that human influences already affected the tropopause. However, it seems that natural variability is still the dominating factor," says Dr. Wuke Wang from GEOMAR, lead author of the study just published in the international journal Scientific Reports. For their study, the researchers used observations for the period 1979-2013 and also climate models. "We were thus able to extend the study period to nearly 150 years. The model allows us to easily look at both human and natural influences and to separate their impacts from each other," explains Prof. Dr. Katja Matthes, climate researcher at GEOMAR and co-author of the study.

Now I am insufficiently educated to understand all of the details of the study (a link to the study is available) but this study proves that the dominant force driving warming of the troposphere is actually the PDO and not antropogenically sourced CO2.

The pacific ocean, the atlantic ocean and the sun are all cooling at this time.

Tired of Control Freaks

a reply to: TiredofControlFreaks

but this study proves that the dominant force driving warming of the troposphere is actually the PDO and not antropogenically sourced CO2.

No, it does not prove that nor does it claim to. The study shows that PDO influences tropospheric temperatures in the tropics. It does not get close to saying that the PDO is the dominant "force" driving global warming.

What the study does do is demonstrate a connection between the PDO and multidecadal cycles in tropical tropospheric temperatures. It show that those peaks and valleys in the warming trend are related to the PDO and provides a mechanism for that connection. It also provides a mechanism for variability in stratospheric water vapor content.

It has been known that there is internal variability in climate. This study provides important information about that internal variability. It does not in any way minimize the effects of anthropogenic CO2 in the warming trend seen in the past 100 years.

a reply to: Phage

"It has long been thought that human influences already affected the tropopause. However, it seems that natural variability is still the dominating factor," says Dr. Wuke Wang from GEOMAR, lead author of the study just published in the international journal Scientific Reports.

sure sounds like it to me

Tired of Control Freaks

a reply to: TiredofControlFreaks

Yes. Did you notice that he said variability and not warming? Variability. Those peaks and valleys. Like the peak in 1998 and the more recent peak. Peaks and valleys in a global warming trend caused by CO2. And again, the paper is about variability in the tropical troposphere. That's the area between 20ºN and 20ºS.

originally posted by: Nathan-D

The airborne fraction is the amount of human CO2 left in the atmosphere after absorption by sinks.

That should read, ‘the fraction of human CO2’ left in the atmosphere. Decreased from 60% to around 50%.

A thought experiment.

Suppose there is X amount of carbon in the atmosphere and Y amount in the oceans prior to humans.

Then humans add H amount of carbon to the atmosphere:

T = 0: Atmosphere: X, ocean Y.
T= 1: Atmosphere X+Ha, ocean Y+Hb. Fraction of human carbon in atmosphere = Ha / (X+Ha)

What happens in equilibrium? Some of the ocean carbon Y atoms goes out to the atmosphere and some of the human carbon atoms in the atmosphere go into the ocean.

So the apparent fraction of human emitted carbon in the atmosphere goes down, as you expect it should from mixing. Now, how much of the net carbon increase in the atmosphere is due to humans? All of it, even though some of the atoms in there used to be in the ocean pre-humans.

originally posted by: Nathan-D
Sure, O2 decreases when anthropogenic CO2 binds to it, but I think any isotopic argument used to try and prove that humans have contributed 40% to the CO2 increase is misleading because anthropogenic CO2 is absorbed rapidly.
...
My ideas? You mean the idea that water releases CO2 when warmed or the idea that to maintain equilibrium water absorbs CO2 when you increase the partial pressure in accordance with Le Chatelier’s principle?
...
Not sure what you‘re getting at here or why you‘re bringing this up.

Yeah, uh, I didn't make an isotopic argument. I pointed out the decline in oxygen levels corresponding to the incline in carbon dioxide levels.

You posit the argument that carbon dioxide is being released from the oceans due to temperature increase. My point is that, wouldn't oxygen be doing so even more? It is substantially more sensitive than carbon dioxide to temperatures, yet we see on that chart that oxygen is declining.

My point about photosynthesis is that there is little turning back. Plants don't recycle carbon dioxide into oxygen; instead, they transform water into oxygen. Oxygen levels will continue to decline as we emit fossil fuels. Worse, plants get more water-efficient with an increase in carbon dioxide, which means reduced oxygen production. Carbon dioxide is going to hang around in the biosphere for a long time.

originally posted by: TiredofControlFreaks
Thank you for proving that burning fossil fuels is the source of CO2 in the atmosphere. But I don't believe that is the issue. The issue is "how sensitive is the climate to the CO2 forcing".

Carbon dioxide by itself has been actually observed to be small but significant, as you've seen in the posts since this one.

Water vapor is by far the most significant greenhouse gas, but its presence in the atmosphere is quite transient and depends on warming that carbon dioxide is responsible for.

a reply to: Phage

Natural Variability is actually the largest portion of the warming in the Tropopause. So PDO being responsible for most of the natural variability is the same as saying that it is responsible for almost all the warming.

As for the rest of the globe, if PDO is responsible for most of the warming (and cooling) in the troposphere over the tropics, it is logical to assume that other ocean currents are responsible for most of the warming (and cooling) in the troposphere over the rest of the globe.

Tired of Control Freaks

a reply to: TiredofControlFreaks

What is the total rate of warming in the Tropopause?

a reply to: Greven




www.quora.com...

Tired of Control Freaks

a reply to: TiredofControlFreaks

Natural Variability is actually the largest portion of the warming in the Tropopause.

Yes. It is also the largest portion of cooling.
Yet, with all that variation between warming and cooling, the average temperature keeps rising. Those peaks (and valleys) are reaching new heights.

it is logical to assume that other ocean currents are responsible for most of the warming (and cooling) in the troposphere over the rest of the globe.

You can assume that if you wish but some data (like that provided in the study) would be more convincing. So, since global temperatures are rising, is it logical to also assume that oceans are getting warmer? What do you suppose might be causing that? What heats the oceans?

You posit the argument that carbon dioxide is being released from the oceans due to temperature increase.

Why would the oceans not be releasing CO2 into the atmosphere if they are warming? It could only not be the case if Henry’s law did not apply to the oceans. But it does apply. Sorry, but you seem to be trying to brush Henry’s law aside and that is not valid. We cannot choose arbitrarily which physical laws of nature we will apply to the real world. It is not a computer-simulation. Henry’s law applies to all cases of gases dissolving in liquids and the dissolution of CO2 in seawater is not an exception to that general rule. Henry’s law deems that as the water-temperature rises, the solubility of gases decrease and more of that gas is released into the atmosphere. In the case of CO2 entering and outgassing from the oceans, the rate at which this can happen is surprisingly fast. The global surface temperature is assumed to have increased by about 1C since 1850 and Henry’s law implies that for every 16K increase in temperature the partial pressure of CO2 doubles (Takahashi et al 2002). Therefore due to solubility change the oceans may have increased the atmospheric CO2 concentration by around 17ppmv, or 6% of the total increase (assuming the industrial partial pressure was 280ppmv). This is lower than Jaworowski’s estimates quoted a few pages back. But this does not account for other environmental parameters that also determine partial pressure, such as changes in ocean biology. For example, in certain ocean regions changes in photosynthesis may cause changes in the CO2 partial pressure of over 100ppmv (Baker 2013: Oceanography: Annals of the International Geophysical Year).

Yeah, uh, I didn't make an isotopic argument. I pointed out the decline in oxygen levels corresponding to the incline in carbon dioxide levels.

I think your argument is the same as the isotopic arguments because the average human CO2 molecule is removed from the atmosphere very rapidly and because of this rapid removal there is only about 4% of human CO2 residing in the atmosphere today. Therefore any isotopic analysis that is used to try and prove that humans are responsible for the total CO2 increase of 120ppmv is null and void in my view, because 96% of all CO2 in the atmosphere today is natural. The O2-content in the atmosphere will be expected to go down as we emit carbon in larger quantities, but that does not mean to say that nature is not contributing to some of the increase. Let us put some numbers on this indefinite statement. Imagine for simplicity that the atmosphere has 1,000,000 molecules of O2 and we emit 10,000 molecules of carbon. The O2-content drops by 1%. Now, at the same time nature emits 2 extra CO2 molecules into the atmosphere and they become a permanent addition to the CO2 greenhouse. What happens to the O2-content? Nothing, as far as I can tell. It still decreases by 1% and that extra naturally-emitted CO2 does not alter that decrease (per meg). The decrease in atmopsheric O2 is measured in per meg (i.e. one molecule of oxygen out of a million molecules of oxygen), not relative to other atmospheric constituents. So nature could emit CO2 and the per meg would not change. Also, O2 in the atmosphere exists in equilibrium with O2 in the oceans anyway, and so the decrease in atmospheric O2 is transitory and would disappear permanently when equilibrium was reached.

It is substantially more sensitive than carbon dioxide to temperatures, yet we see on that chart that oxygen is declining.

Where did you hear that oxygen (O2) was ‘more sensitive than CO2 to temperature?’ The ChemEngineering page on Henry’s law (see here) gives an equation for adjusting the solubility value of kH in Henry’s law according to water-temperature. In fact it gives two equations and I took the 1st, or upper one as being the appropriate one in this case: kH,pc = kH,pcºexp[−C⋅(1/T−1/Tº)]. Where kH is Henry’s constant, kH,pcº is 769.23 (for O2), exp stands for exponential, T is the thermodynamic temperature in K, Tº refers to the standard temperature in K (298) and -C is -1700 (for O2). According to that equation, increasing the water-temperature by 1K (from 298K to 299K) changes kH from 769.23 L·atm/mol to 784.047, giving a decrease in solubility of about 1.9%. CO2 on the other hand gives a decrease of 2.7% (from 29.4 L·atm/mol to 30.2). The page on Henry’s law also gives a solubility for O2 of 796.23 L·atm/mol (atmospheres per mole per litre) whereas CO2 is 29.4 L·atm/mol. So CO2 is around 27 times more soluble than O2 (796.23/29.4). As Kazim et al (2012) points out ‘The solubility of carbon dioxide is 26 times higher than oxygen’. Therefore heating water would increase the CO2 concentration more than O2, as it is not only more sensitive to temperature but also more soluble. There may be a higher absolute concentration of O2 in the oceans than CO2 (DIC included) (any figures?), but because of its lower solubility and comparatively lower sensitivity to temperature, the atmospheric O2 concentration would change less (as a percentage).

So the apparent fraction of human emitted carbon in the atmosphere goes down, as you expect it should from mixing. Now, how much of the net carbon increase in the atmosphere is due to humans? All of it, even though some of the atoms in there used to be in the ocean pre-humans.

What you appear to have described here as far as I can tell is the mass-balance argument. To describe it more simply, the IPCC and the Keeling Curve tell us that atmospheric CO2 is accumulating at the rate of about 16 Gts (“gigatonnes”, or billions of tons) per year in total. However this varies dramatically. The IPCC estimates that human CO2 emissions amount to about 33 Gts per year (AR5 2013) and natural ones amount to 724 Gts per year, making about 750 Gts per year in total. Now, you appear to be saying that of the 33 Gts year emitted by humanity about half (i.e. 16.5 Gts/year) are absorbed by natural sinks and the remainder (also 16.5 Gts/year) stays in the atmosphere as the human contribution to the CO2 greenhouse. Since the total residual deposited in the atmosphere is about 16 Gts/year this would mean that humans are responsible for the entire CO2 increase, since if the sinks had not absorbed any human CO2 the increase should be 33 Gts/year. However, as pointed out a few pages back, this ignores Henry’s law. Water can absorb the majority of CO2 added to the air while at the same time releasing CO2 due to a change in temperature. I gave a thought experiment explaining this a few pages back, but apparently it went unnoticed. In any case, I have accepted that the majority of the CO2 increase is due to humans.

I wrote:

Imagine for simplicity that the atmosphere has 1,000,000 molecules of O2 and we emit 10,000 molecules of carbon. The O2-content drops by 1%.

That should be 2,000,000, assuming a 1% change.

a reply to: Phage

no it is not logical to assume the ocean is getting warmer.

If the atmosphere is getting warmer, it is because the ocean is giving up its heat.

As discussed previously in this thread, the amount of heat given up by the ocean was huge, as it was in 1998. After the 1998 El Nino, we experienced the next 16 years with no warming. Its clear during this time that the ocean was heating up until the 2015-2016. Then another huge discharge of heat. That is about a 30 year time period.

So now we have the Atlantic turning cool and the Pacific turning cool and the Antarctic turning cool. By what process, I do not know but it seems that the oceans have "coupled" and are now in the same cool state. Its clear that the oceans are ready to absorb heat again. That means that the atmosphere will cool.

When I look at historic temperatures - there is a 30 year pattern of heating and then cooling. With the sun also being at a minimum, its clear that whatever switch has been flipped, we are on the brink of a cooling period that has nothing to do with CO2.

Tired of Control Freaks

a reply to: TiredofControlFreaks

If the atmosphere is getting warmer, it is because the ocean is giving up its heat.

From where did it get the heat and why is it "giving it up?"

So now we have the Atlantic turning cool and the Pacific turning cool and the Antarctic turning cool.

False.
www.nodc.noaa.gov...
www.ospo.noaa.gov...
www3.epa.gov...

When I look at historic temperatures - there is a 30 year pattern of heating and then cooling.

I see peaks and valleys in a warming trend.

a reply to: Phage

The oceans gain heat from the sun and the atmosphere. As you have often pointed out, we have had a 30 year or so of warming.

Whether you see only "peaks and valleys" is irrelevant. Look at 30 year time periods instead of monthly or yearly data.

There is little doubt that there was below average temperatures for the 30 year period prior to 1980.

I am sorry, I should have said the AMO and the PDO are both entering cool phases.

Now that they are coupled - we should start to see overall cooling.

By the way, showing me data from when the EL Nino was underway doesn't prove anything.

Tired of Control Freaks
Tired of Control Freaks

originally posted by: TiredofControlFreaks
a reply to: Phage

Natural Variability is actually the largest portion of the warming in the Tropopause. So PDO being responsible for most of the natural variability is the same as saying that it is responsible for almost all the warming.

No it isn't, because the warming trend is that which is not variability.

As for the rest of the globe, if PDO is responsible for most of the warming (and cooling) in the troposphere over the tropics, it is logical to assume that other ocean currents are responsible for most of the warming (and cooling) in the troposphere over the rest of the globe.

Ocean currents are responsible for heat transport, not heat creation or dissipation.

Global warming comes from physics---changes in the boundary conditions.