The CO2 Problem in 6 Easy Steps

[orogenicman]

The "natural" cycle now is trying to cool the earth, as has been happening since the Holocene Climate Optimum. Since it's currently warming, that would be one conclusively refutation of the weird claim that a natural cycle is currently driving climate.

The trend has been towards warmer since the end of the Ice Age 14,000 years ago. There have been periods in between that have been both warmer and cooler.....all following some sort of cycle.

What sort of cycle, where?

It would be nice if you would present evidence for your claims instead of recycling right wing propaganda.

 

[Toddsterpatriot]

The "natural" cycle now is trying to cool the earth, as has been happening since the Holocene Climate Optimum. Since it's currently warming, that would be one conclusively refutation of the weird claim that a natural cycle is currently driving climate.

The "natural" cycle now is trying to cool the earth

I guess we should burn more coal, ice ages really suck.

 

[mamooth]

The ice age is 50,000 years off. Your peculiar plan is like saying I should run my furnace full blast right now, because winter will eventually arrive in several months.

 

[daveman]

Innnocents murdered? That would be your billet. When people start dying of starvation and thirst from climate changes that might have been ameliorated if not for you fossil fuel pawns holding us off - you can pull your grandkid up on your knee and say "I did that"!

If you had the science on your side, you wouldn't have to resort to pathetic fear-mongering.

Some ends justify some means. Jim Hansen hasn't done anything that even a cranky, half-assed sort of a god wouldn't forgive him for. I can't say the same for you.

And now you claim to speak for God.

Are you ever going to do anything to merit the level of arrogance you display? NOTE: Being a mindless progressive is not an accomplishment. It's a handicap.

 

[daveman]

Poor Dave. Ever deeper into the conspiracies he goes. They're all he has, all he'll ever have. And the world simply moves on without him, after a short stop to point and laugh.

It's probably for the best. You should do what you do best, and Dave is best at being a conspiracy parrot.

...says the cultist.

More projection on your part. Seek help.

 

[Toddsterpatriot]

The ice age is 50,000 years off. Your peculiar plan is like saying I should run my furnace full blast right now, because winter will eventually arrive in several months.

Ice ages are much worse than Climatic Optimums.

 

[Crick]

That doesn't mean a 5C temperature rise in the next century would be ice cream and cake.

 

[CrusaderFrank]

If it's 8 degree warmer than it was 14,000 years ago, how the fuck is this a "Natural cooling cycle" Is the AGWCult really THAT FUCKING STUPID?

 

[Toddsterpatriot]

That doesn't mean a 5C temperature rise in the next century would be ice cream and cake.

You never said what a Climatic Optimum is or why they called it that.

I wonder why?

 

[jc456]

The CO2 problem in 6 easy steps

6 August 2007

We often get requests to provide an easy-to-understand explanation for why increasing CO2 is a significant problem without relying on climate models and we are generally happy to oblige. The explanation has a number of separate steps which tend to sometimes get confused and so we will try to break it down carefully.

Step 1: There is a natural greenhouse effect.

The fact that there is a natural greenhouse effect (that the atmosphere restricts the passage of long wave (LW) radiation from the Earth’s surface to space) is easily deducible from i) the mean temperature of the surface (around 15ºC) and ii) knowing that the planet is roughly in radiative equilibrium. This means that there is an upward surface flux of LW around \sigma T^4 (~390 W/m2), while the outward flux at the top of the atmosphere (TOA) is roughly equivalent to the net solar radiation coming in (1-a)S/4 (~240 W/m2). Thus there is a large amount of LW absorbed by the atmosphere (around 150 W/m2) – a number that would be zero in the absence of any greenhouse substances.

Step 2: Trace gases contribute to the natural greenhouse effect.

The fact that different absorbers contribute to the net LW absorption is clear from IR spectra taken from space which show characteristic gaps associated with water vapour, CO2, CH4, O3 etc (Harries et al, 2001; HITRAN). The only question is how much energy is blocked by each. This cannot be calculated by hand (the number of absorption lines and the effects of pressure broadening etc. preclude that), but it can be calculated using line-by-line radiative transfer codes. The earliest calculations (reviewed by Ramanathan and Coakley, 1979) give very similar results to more modern calculations (Clough and Iacono, 1995), and demonstrate that removing the effect of CO2 reduces the net LW absorbed by ~14%, or around 30 W/m2. For some parts of the spectrum, IR can be either absorbed by CO2 or by water vapour, and so simply removing the CO2 gives only a minimum effect. Thus CO2 on its own would cause an even larger absorption. In either case however, the trace gases are a significant part of what gets absorbed.

Step 3: The trace greenhouse gases have increased markedly due to human emissions

CO2 is up more than 30%, CH4 has more than doubled, N2O is up 15%, tropospheric O3 has also increased. New compounds such as halocarbons (CFCs, HFCs) did not exist in the pre-industrial atmosphere. All of these increases contribute to an enhanced greenhouse effect.

Step 4: Radiative forcing is a useful diagnostic and can easily be calculated

Lessons from simple toy models and experience with more sophisticated GCMs suggests that any perturbation to the TOA radiation budget from whatever source is a pretty good predictor of eventual surface temperature change. Thus if the sun were to become stronger by about 2%, the TOA radiation balance would change by 0.02*1366*0.7/4 = 4.8 W/m2 (taking albedo and geometry into account) and this would be the radiative forcing (RF). An increase in greenhouse absorbers or a change in the albedo have analogous impacts on the TOA balance. However, calculation of the radiative forcing is again a job for the line-by-line codes that take into account atmospheric profiles of temperature, water vapour and aerosols. The most up-to-date calculations for the trace gases are by Myhre et al (1998) and those are the ones used in IPCC TAR and AR4.

These calculations can be condensed into simplified fits to the data, such as the oft-used formula for CO2: RF = 5.35 ln(CO2/CO2_orig) (see Table 6.2 in IPCC TAR for the others). The logarithmic form comes from the fact that some particular lines are already saturated and that the increase in forcing depends on the ‘wings’ (see this post for more details). Forcings for lower concentration gases (such as CFCs) are linear in concentration. The calculations in Myhre et al use representative profiles for different latitudes, but different assumptions about clouds, their properties and the spatial heterogeneity mean that the global mean forcing is uncertain by about 10%. Thus the RF for a doubling of CO2 is likely 3.7±0.4 W/m2 – the same order of magnitude as an increase of solar forcing by 2%.

There are a couple of small twists on the radiative forcing concept. One is that CO2 has an important role in the stratospheric radiation balance. The stratosphere reacts very quickly to changes in that balance and that changes the TOA forcing by a small but non-negligible amount. The surface response, which is much slower, therefore reacts more proportionately to the ‘adjusted’ forcing and this is generally what is used in lieu of the instantaneous forcing. The other wrinkle is depending slightly on the spatial distribution of forcing agents, different feedbacks and processes might come into play and thus an equivalent forcing from two different sources might not give the same response. The factor that quantifies this effect is called the ‘efficacy’ of the forcing, which for the most part is reasonably close to one, and so doesn’t change the zeroth-order picture (Hansen et al, 2005). This means that climate forcings can be simply added to approximate the net effect.

The total forcing from the trace greenhouse gases mentioned in Step 3, is currently about 2.5 W/m2, and the net forcing (including cooling impacts of aerosols and natural changes) is 1.6±1.0 W/m2 since the pre-industrial. Most of the uncertainty is related to aerosol effects. Current growth in forcings is dominated by increasing CO2, with potentially a small role for decreases in reflective aerosols (sulphates, particularly in the US and EU) and increases in absorbing aerosols (like soot, particularly from India and China and from biomass burning).

Step 5: Climate sensitivity is around 3ºC for a doubling of CO2

The climate sensitivity classically defined is the response of global mean temperature to a forcing once all the ‘fast feedbacks’ have occurred (atmospheric temperatures, clouds, water vapour, winds, snow, sea ice etc.), but before any of the ‘slow’ feedbacks have kicked in (ice sheets, vegetation, carbon cycle etc.). Given that it doesn’t matter much which forcing is changing, sensitivity can be assessed from any particular period in the past where the changes in forcing are known and the corresponding equilibrium temperature change can be estimated. As we have discussed previously, the last glacial period is a good example of a large forcing (~7 W/m2 from ice sheets, greenhouse gases, dust and vegetation) giving a large temperature response (~5 ºC) and implying a sensitivity of about 3ºC (with substantial error bars). More formally, you can combine this estimate with others taken from the 20th century, the response to volcanoes, the last millennium, remote sensing etc. to get pretty good constraints on what the number should be. This was done by Annan and Hargreaves (2006), and they come up with, you guessed it, 3ºC.

Converting the estimate for doubled CO2 to a more useful factor gives ~0.75 ºC/(W/m2).

Step 6: Radiative forcing x climate sensitivity is a significant number

Current forcings (1.6 W/m2) x 0.75 ºC/(W/m2) imply 1.2 ºC that would occur at equilibrium. Because the oceans take time to warm up, we are not yet there (so far we have experienced 0.7ºC), and so the remaining 0.5 ºC is ‘in the pipeline’. We can estimate this independently using the changes in ocean heat content over the last decade or so (roughly equal to the current radiative imbalance) of ~0.7 W/m2, implying that this ‘unrealised’ forcing will lead to another 0.7×0.75 ºC – i.e. 0.5 ºC.

Additional forcings in business-as-usual scenarios range roughly from 3 to 7 W/m2 and therefore additional warming (at equilibrium) would be 2 to 5 ºC. That is significant.

Q.E.D.?

--Gavin Schmidt - Director, NASA Goddard Institute for Space Studies

RealClimate: The CO2 problem in 6 easy steps

Just show the supporting work for all of this and then this becomes useful. without proof, it is all still the same old mumbo jumbo you can't backup! Let's see the experiment that doubling CO2 causes a 3 degree C change in temperature. you make the claim, back it up!!!

The links to the supporting work is embedded in the paper, the link to which was provided. What? You didn't open the link and check it out?

Instructions for opening web links:

1) You scroll to the link, and left click on it. Enjoy already...

Well s0n I did look at all of the links, like I stated in my orginal post the same old mumbo jumbo. There is no experiment in any of the referenced links. Feel free to point out the one I missed, but all I found when wasting my time was calculations, models and publications of forcing hypothesis'. He claimed a 3 degree C change in temperature with a CO2 doubling. I want the evidence that supports that statement. I see you don't have that experiment either. I'm not surprised.

 

[Crick]

That doesn't mean a 5C temperature rise in the next century would be ice cream and cake.

You never said what a Climatic Optimum is or why they called it that.

I wonder why?

Because the question was just that stupid. We know what the Holocene Optimum WAS. What an "optimum" might BE in this context is unknown and unknowable. If you think differently, please enlighten us.

 

[Toddsterpatriot]

That doesn't mean a 5C temperature rise in the next century would be ice cream and cake.

You never said what a Climatic Optimum is or why they called it that.

I wonder why?

Because the question was just that stupid. We know what the Holocene Optimum WAS. What an "optimum" might BE in this context is unknown and unknowable. If you think differently, please enlighten us.

We know what the Holocene Optimum WAS.

Excellent! What was it? Why did they call it that?

 

[mamooth]

Todd, if you don't know the answer, don't expect us to tell you. Do your own research.

And after you do, then explain why you think your question isn't really really stupid. Because it is really stupid. Some say there's no such thing as a stupid question, but you're proving them wrong.

 

[Toddsterpatriot]

Todd, if you don't know the answer, don't expect us to tell you. Do your own research.

And after you do, then explain why you think your question isn't really really stupid. Because it is really stupid. Some say there's no such thing as a stupid question, but you're proving them wrong.

Why don't you tell me why they call them climatic optimums?

What are you afraid of?

 

[Crick]

I think we can guarantee that every native speaker of English here knows why they are called "optimums". But this has as much real value as the claim that scientists were forced to go from "global warming" to "climate change" because of some unidentified failure of the evidence.

The lead post here presents an explanation of the evidence and the reasoning which supports AGW. It involves no climate models. It involves no esoteric, bleeding edge science. It is clear, concise and rational. If you can make a case against any of the six points made there, please do. If you cannot, perhaps you ought to have the cajones to be able to admit it. All of you.

ps: no one will EVER be afraid to deal with you on any scientific issue, Todd. Ever.

 

[Kosh]

People are never told that the most powerful greenhouse gases by orders of magnitude is water vapor and clouds. When only human emitted CO2 is considered, less than one percent of the greenhouse gas potential comes from human activity. Yet, all the global warming is supposed to be attributed to it. Water vapor plays a huge role in keeping the earth warm; 70 times more powerful than the CO2 emitted by human activity. When clouds are added, CO2 becomes even less important. However, clouds not only trap heat, low elevation clouds also reflect much of the incoming solar radiation, so the sun's heat never reaches the earth's surface which cools the earth. It is this mechanism that a growing number of scientists believe is one of the primary mechanisms warming and cooling the earth.

Of all the carbon emitted into the atmosphere each year, 210 billion tons are from natural sources, and only 6.3 billion tons are from man's activity. Man's burning of fossil fuel, therefore only accounts for 3 percent of total emissions of CO2.

 

[Toddsterpatriot]

I think we can guarantee that every native speaker of English here knows why they are called "optimums". But this has as much real value as the claim that scientists were forced to go from "global warming" to "climate change" because of some unidentified failure of the evidence.

The lead post here presents an explanation of the evidence and the reasoning which supports AGW. It involves no climate models. It involves no esoteric, bleeding edge science. It is clear, concise and rational. If you can make a case against any of the six points made there, please do. If you cannot, perhaps you ought to have the cajones to be able to admit it. All of you.

ps: no one will EVER be afraid to deal with you on any scientific issue, Todd. Ever.

I think we can guarantee that every native speaker of English here knows why they are called "optimums".

Is it because warm weather is better than cold weather?

But this has as much real value as the claim that scientists were forced to go from "global warming" to "climate change" because of some unidentified failure of the evidence.

Did they change it because their evidence for "global warming" was correct?

 

[freedombecki]

I think we can guarantee that every native speaker of English here knows why they are called "optimums". But this has as much real value as the claim that scientists were forced to go from "global warming" to "climate change" because of some unidentified failure of the evidence.

The lead post here presents an explanation of the evidence and the reasoning which supports AGW. It involves no climate models. It involves no esoteric, bleeding edge science. It is clear, concise and rational. If you can make a case against any of the six points made there, please do. If you cannot, perhaps you ought to have the cajones to be able to admit it. All of you.

ps: no one will EVER be afraid to deal with you on any scientific issue, Todd. Ever.

I think we can guarantee that every native speaker of English here knows why they are called "optimums".

Is it because warm weather is better than cold weather?

But this has as much real value as the claim that scientists were forced to go from "global warming" to "climate change" because of some unidentified failure of the evidence.

Did they change it because their evidence for "global warming" was correct?

Oh, the silence of the lambiekins.

 

[protectionist]

Plant MORE trees.

 

[Crick]

Oh, the silence of the lambiekins.

Is ocean acidification "global warming"?
Is increased storm intensity "global warming"?
Are changes in rain patterns "global warming"?
Are shifts in ocean currents "global warming"?
Is the recession of the West Antarctic grounding line "global warming"?
Is the increase in Antarctic sea ice "global warming"
Are the changes in the timing of a thousand biological cycles "global warming"?

The evidence for global warming is correct and it is overwhelming. You have no refutation. You have no replacement causation. You have virtually NO scientists on your side of this argument.