Can you effectively argue the other side re: AGW?

Question

Skepticism - the method of suspended judgment, systematic doubt, or criticism that is characteristic of skeptics (Merriam–Webster).

Assuming for the sake of this skeptical exercise that warming is happening, can you "suspend judgement" and argue the "other side" on whether or not the current warming is anthropogenic (caused by mankind)?

If you normally lean towards the conclusion that global warming is caused by us, argue that it is not. If you normally suspect that the current warming is natural, tell us how it's caused by us.

a. Can you explain what is causing the warming?

b. What will be the outcome?

c. What action should be taken (if any)?

I'll do it too. It'll be interesting to see if I can do it effectively, and whether or not my approach will then resemble folks taking the contrary position here.

I respectfully request that you engage in this question as asked, or skip it. Please join me in reporting trolls who simply drop in to disrupt rational discussion.

Answer 1

That's a very tall order but since I can do this with evolution I'll give it a try.

I'm a confirmed skeptic, not just on AGW but on nearly all topics, so I'll have to put that on hold and try to buy into AGW. First, I try to convince myself that the laws of nature no longer apply, that an increase in CO2 always leads to a corresponding increase in temperature. Since this requires I ignore ice core data going back half a billion years showing levels of CO2 10 times higher than today during an ice age, this is very difficult. Fail.

Okay, maybe it's not a direct link, but in a lab CO2 will block a certain amount of a few wavelengths of infrared radiation. It must be able to do this in the greater world, right? So, with a feedback with water vapor, as the IPCC proposes, then...wait. If CO2 causes heating and more water vapor, and water vapor is a much greater cause of global warming than CO2, wouldn't that enter a feedback loop and cause the runaway warming that Al Gore talked about? Yes. But it never has, which is a problem for my argument. More CO2 means warming, plus the warming from evaporating oceans leading to more water vapor which causes additional warming which warms the oceans further releasing more CO2 which....

No, that's not possible no matter how convincingly the IPCC report makes it sound, else the temp now would rival that on Venus and we'd have no liquid water at all.

What's left? If it's not CO2 then maybe it's the water vapor we produce thru respiration and perspiration. I suggest we all use spacesuits to keep our harmful emissions out of the environment. We could be buried in them, too to prevent our CO2 from decomposition from entering the atmosphere. It doesn't sound like a good solution, but it's not possible to frame this argument in a convincing way without sounding absurd. That's always a risk with absurd arguments.

What is causing the warming then? The same as always, our sun. It may not be direct warming thru increased irradiance, but we know a bit about black body radiation and cosmic ray interaction in our atmosphere, not enough to be sure of anything but enough to know how little we know. It may have to do with the Earth's core and volcanic activity that doesn't lead to an eruption. We also know that the "vacuum" the Earth moves thru isn't actually empty at all, it just has a much lower particle density than we enjoy here. Maybe we periodically move thru some matter that causes complex interactions with our climate. But the most likely cause is the sun. The solar cycle of sunspot activity and magnetism, changes in irradiance, the effect of Jupiter's massive interaction with the sun and many other factors.

I agree with your ideas on insurance, if you choose to build in a flood plain or near areas you should reasonably expect to be threatened by sea level increases like we've seen for centuries, then you're on your own. If you can't get insurance, don't build there and expect taxpayer's to endlessly make up for you poor decisions. It's like me planting corn in the Nevada desert, then asking for federal help for my crop failures, I really shouldn't expect help for my own bad judgment.

***edit Link provided. The Fail comment is my judgment of my failure to defend my first argument and it's hard to look at the data and still believe that CO2 is the main driver of our recent warming. If CO2 levels were 10 times higher than they are now, during an ice age, it's a bit of a dilemma I think.

As for those who fail to try this exercise, if you don't understand the other side's arguments enough to state them then maybe your refutation of them is weak. That may be why so many advocates of AGW here only list names of individuals and groups who have jumped on the bandwagon. Either it's CO2 or it's not and clearly I for one am unable to prove that CO2 drives temp, it's the other way around.

Answer 2

It's a good question and I admit honestly I can't.  It's too much of a stretch.  

When I first saw the Mauna Loa graph in the late seventies as a teenager, I had no idea about global warming or cooling or any of it, except that the article with the graph probably explained the role of CO2 in the atmosphere.

I looked at the graph and thought oh, that's it then.  

We have the unmoveable object (mankinds dependence of fossil fuels) meets the irresistible force (physics);  this should make for an interesting rest of my and everyone else's lifetime.  

You think about these kind of existential things when you're 17.  It took 30 years, but now things really are getting "interesting".  Finally.

If you are interested, I'll explain more.

Answer 3

I'm with Blob.  Can't do it.

Among other things, it would be quoted ad nauseum here as "proof" that global warming isn't real, and mostly caused by us.  I'm not about to provide that argument, and then have to explain why I argued that for the rest of my days.  I've got enough problems here :-).

EDIT - Bawk,  bawk bawk bawk.

Answer 4

Arguing for a position one's convinced is false is more in the realm of a high-priced defense Attorney or PR specialist than a actual skeptic or scientist.  The skeptic or scientist is motivated by a pursuit of truth, not a desire to win a debate.

I can certainly understand the arguments on the other side, but any attempt to convince someone using them isn't worthy of my time and would probably leave a bad taste in my mouth.  Additionally, as Bob suggested, I'd probably do it better than the doubters and I don't want to end up debating myself.

Answer 5

Carbon isotopes in ratio to C12.

Answer 6

Good exercise.

Don't see natural cycles or solar output as the major driver for AGW since they are already very well known considered in the predictions. The high radiative forcing properties of CO2 are well known so that is not really in doubt.  The primary sources of CO2 are know and documented - not much doubt.  

The real argument to make I think is what will be the response of the various ecosystems to the change in climate.  The change in climate is not in doubt, although you may think it is either all natural or humans contribute significantly to the causal factors.

Plants  (aquatic and terrestrial) absorb CO2 and use water more efficiently as well as make more photosynthate as CO2 increase in the atmosphere.  Some of the solar energy is taken up as latent heat (I think this is right) from the phase change of water, so it may have less effect on the earth.   This may offset some of the change.  Of course the earth is 3/4 water so it would be tough to grow enough plants.

The oceans ,as you point out are a major factor, probably the major factor, in determining the how much the climate will change.  They directly absorb CO2 jsut because of concentration gradient (high concentration transfers to lower).  This will contiune up to an unknown point. It will reverse if the gradient in the ocean becomes to large for some reason.  

The ocean currents are controlled by more than just plate tectonics.  It is a heat/energy transfer mechanism - so are weather system.  Energy is transfered for areas of high energy (like the equator) to areas of low energy (the poles).  Plain physics. Cold water contracts and gets dense and sinks, and water moves in to fill the void from.  The water moving in is warmer, from the equator.  it cools and sinks and fo on pushing the water below it along the ocean floor.  As the warm water near the oceans surface at the equator starts to move away from the poles because of convection, cooler water up-wells and is heated.  The specific location of current is mostly control by the shape of the land masses and plates, but some of the movement is induced by the heat gradient between the equator and poles.  This is a very light treatment of the subject and ignores a lot.

The moderating effect of the ocean is well know, but we don't know how much heat it may absorb and offset.  The effects of plants is is also known, but how much of an offset this will provide is unknown.  The cooling effect evapotranspriation is well known and this will lead to increased cloud cover.  Depending of the types of clouds formed, this could counteract global warming by reflecting more sunlight away.  there is no doubt there are natural factors "resisting" warming.  

The causes of global warming are certain - it is radiative forcing from greenhouse gases that are mainly produced from anthropogenic activity.  Natural factors play a role, but we can't influence these. We can control the gigatons per year of carbon we put in the air.  The pre-industrial revolution CO2 concentration was 255 ppm?  Now it's 380 ppm? this is a 50% increase [(380-255)/255 x 100].  Not all is due to human activity but a lot is.  A 50% increase in a highly radiatively forcing gas like CO2 is like increasing the number of 100 dollar bills in your pocket by 50%.  It means a lot more than increasing the $1 bills.  This is why there is a problem. Because although CO2 is a very minor component of the atmosphere, it plays a major role in keeping the planet habitable (think I remember 15 degrees F warmer average temperature on the plant because of CO2, but it has been a while so my memory may not be right).  The fact that CO2 is one of the primary gases responsible for the natural green house effect and AGW is not really in dispute.

The many outcomes are uncertain - there are many natural factors that may offset warming.  Conversely, there are also factors that will contribute (more CO2 and methane from decay, more humidity and increase in atmospheric water, less ice and snow), but we are not as good at predicting the ecological effects.  This could balance in a favorable way for the environment and people.

The economic consequences depend on the environmental factors so they are even more uncertain.  We could need to spend more of cooling, but this could be offset by heating.  May get more food per acre of land, but may be more expensive to work land in some places.  May need to spend more to protect cities from flooding, storms etc, and some diseases may become more common that were once eradicated in the US (Malaria for example),  but it may not be as bad as it could be if natural factors offset warming.

What to do is to take reasonable steps to reduce greenhouse gas emission (conservation, invest in technology for sustainable energy resources, I don't think cap and trade or limiting emissions is out of the question, but that is radical for a lot of people and would need to be discussed in the context of the events we see happening and what the effect of sonservation and technology are predicted to be.