Climate Change: Are Humans to Blame?
 

Or so says yesterday's Washington Post, served up fresh on my Kindle -House Panel Continues Debate on Climate-Change Bill.

Congress also heard from Climate Change skeptics, which are a distinct but vocal minority. With such an overwhelming consensus among scientists working in fields of biology, climatology, geology, meteorology, etc., all stating that climate change is a real threat, that the average temperatures are rising globally and that Arctic ice and the world's glaciers are melting, and that humans are part of the problem -can there really be any skeptics that get taken seriously?

To be honest, I'm not an expert on climate change and haven't followed it more than a moderate degree. Assuming others participate, and using this thread as a vehicle for education, I intend to evaluate the issue objectively. I truly have no bias one side or the other. If the data are sufficient to sway one way or the other, thats where provisionally draw my conclusions.

If others have evidenced based arguments for one side of this or the other, please feel free to post them here. A google search for "climate change" yielded this image from Wikipedia, which is a graph based on the data compiled by Meehl et al. (2004). It correlates both modeled and observed temperature changes with the fluctuations in greenhouse gases.

http://upload.wikimedia.org/wikipedi...ttribution.png

In addition to the strong correlations of their data, there's the added support for the validity of climate modeling to accurately reflect observed temperatures, which seems to refute the common argument by global warming skeptics that climate modeling is inaccurate and too flawed to rely on.

Reference:

Meehl, G.A., W.M. Washington, C.A. Ammann, J.M. Arblaster, T.M.L. Wigleym and C. Tebaldi (2004). "Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate". Journal of Climate 17: 3721-3727.

I haven't visited the site in a while, but I used to enjoy the spirited discussion found here.

And I posted this once upon a time, but I can't remember whether it was here or Kavar's.

The Most Terrifying Video You'll Ever See

When some of the skeptics happen to be the ones whose papers were used, I'd say that yes you should pay attention to some of what they say.

And if you want to base it on number of followers, That's almost like saying, There must be a god because so many people believe in one.

Personally, I'm not basing anything on anything else, particularly not the number of followers. I'm asking for premises and supporting information for both sides, assuming that the topic is one others are willing to discuss.

With regard to the "skeptics [...] whose papers were used," would you care to share those citations? I think they'd be interesting to read and see the counter position.

Wow. I hadn't seen that before - thanks for sharing it again, Achilles. It's brilliant and very effective due to its simplicity.

Definitely something to bookmark ;)

_EW_

Couldn't find the original article(which was regarding the IPCC) However...
http://epw.senate.gov/public/index.c...0-274616DB87E6

You're welcome :)

Regardless of whether climate change is a) an actual phenomenon and/or b) man-made, conservation, clean energy, etc all make sense. I hope that viewers will take that away, if nothing else.

That's really strange... it's a .gov site but has the style and format of one of those blogs Garfield used to link. Still, I'll get a chance to look it over later. Thanks for the link.

Sources? It's easy to make any claim, but if we're to accept this "argument from authority", I'm kinda curious to know how many cooks are stirring that brew. The problem with the global warming argument is that there's been a push to avoid using the label "global warming" and substitute supposedly less polarizing ones like global climate change. Nothing like an innocuous sounding euphemism. ;) Seems like a lot of the mmgw arguments are based on..."but what if....."

Is that supposed to make everyone think you're really open minded about this thread?

While I disagree on the level of man's involvement in actual climate change, I think we do enough damage to the environment. We dump tonnes of trash, gallons of chemicals, and use a metric eff-tonne of non-renewable resources. Responsible environmentalism works on fixing those things, not attempting to change some percieved threat that may or may not be related to man's involvement.

I can agree with that. Balancing man's need to improve civilization with trying not to destroy his environment ain't always an easy thing. However, we shouldn't rush headlong into ginning up a crisis to advance agendas either. Part of the problem with the global warming crowd is their knee jerk embracing of polemics to scare people. I guess they figure that like a stopped clock they'll be right at least once (someday).

The problem is that many of their policies end up being made into laws by people who don't look much farther than votes. So neo-scientific mumbo-jumbo gets re-interpreted by non-scientists into some form of law...

Oh and I don't pretend that that senate site is unbiassed. It's the minority blog. However, it gives you some idea of who the so called fringe scientists are.
Also of note, notice how they seem to be backing off the Global warming talk since the temps have actually gone DOWN these last few years. Oh wait... now it's Global Climate Change, since warming was easy enough to disprove. The old hockey stick graph makes it's rounds again.

Sources for a consensus? I thought this was already common knowledge, but okay. Try van den Hove (2003); Oreskes (2004); and Kintishch, Eli (2009).

I'm not asserting the consensus is right, only that there is a consensus. To me, the data are more important.

From a scientific perspective, I see this as a more accurate term and as a strength of science that it's willing to accept conclusions provisionally. You should be more worried if the scientific consensus was unwilling to change or adapt with better data and understanding.

Yes. I am. I truly don't know what to think since I haven't examined the data. I'm looking at more and more in peer-reviewed journals and, so far, it all appears to be in support of anthropogenic climate change. I'm actively looking in the major peer-reviewed journals for specific studies that show otherwise as I type this.

I would, however, point out that, given your rhetoric above which irrationally criticizes the provisional nature of science, your own bias is clear. Since it is, I'm curious: what motivates a bias against the premise that climate change is happening or is accelerated by human activity?

Edit: I took a look at the link above. I see why it looks like Garfy's blog links as well: it's a blog run by Senator Inhofe and only has the .gov domain because of his position in the Senate. It isn't actually representative of the U.S. government nor did I notice any references to sources. Though I admit it was hard to read with all the gaudy caps, bolds, colors, etc. reminiscent of the extreme conservative blogs Garfy posted.

References:

Kintisch, Eli (2009). Projections of Climate Change Go From Bad to Worse, Scientists Report. Science, 323(5921), 1546-1547.

Oreskes, Naomi (2004). The Scientific Consensus on Climate Change. Science, 306(5702), 1686.

van den Hove, S.; Le Menestrel, M.; de Bettignies, H.-C. (2003). Climate Policy 2 (1), 3.

Ah. Yeah, it was hard to follow. I noticed names and places of origin, but not citations to studies. Lots of quotes without benefit of context.

Every study I've looked at regarding global temperatures shows a steady increase in surface temperatures: every model and every observation, and the observations corroborate the models when trend-lines are shown. So, it appears its both accurate and appropriate to still say "global warming" when you're discussing the specific issue of temperatures and the effects of temperatures (i.e. melting polar/glacial ice which raises sea levels). If you're looking at other issues of global warming, its more appropriate to use "climate change" since the warming can affect climate systems. It may be warmer in most parts of the globe, but, because of these systems, a cooling effect may be observed in some regions. The net effect, would still be warming.

Where can I find data or studies that show this "cooling?"


Reference on current warming trends:

Ting, Mingfang; et al (2009). Forced and Internal Twentieth-Century SST Trends in the North Atlantic. Journal of Climate, 22(6), 1469-1481.

http://www.climatecooling.org/
Note: I haven't vetted the page, It was just the first I saw.
But with the data showing lower solar sun spot activity as of late correlating with the decreases in temperature. it seems to make sense.

The most relative link I saw there pointed to a NOAA site, which I liked: U.S. Annual Climate Review for 2008, which has data that shows a distinct cooler trend for 2008 over the previous few years.

However, the overall trend is still an increase. We'll need a few more years to determine whether the cooling is part of the normal fluctuations or a trend in the opposite direction.

I'll have to look over the other links tomorrow.... the bed calls.

It's your use of terms like overwhelming that caused me to be curious as to just how many scientists there were that composed this "overwhelming concensus". Hence my query.

That's one way of spinning it. Frankly, I think that as the term "global warming" was becoming too controversial a moniker, they opted for another term. Science adapted, but more to the political realities than the scientific ones.

Nice piece of rhetoric yourself. I'm not irrationally criticizing the "provisional nature of science", but don't buy the spin for the name change either. I don't state anywhere that the climate is static, so you're making quite a leap.

From your posts, at least to me, it seems like you're completely writing off the scientific aspects of climate change and instead looking at it strictly politically.

No, merely opposed to the unquestioning leap many make to the conclusion that manmade global warming is the problem.

What, then, is the evidence that it is or isn't?

As for the general trend that many who would consider themselves "green" take, which *is* that global warming is caused by people, it may just be that this is a very intuitive leap given that the current world population and impact that this population appears to have on the immediate environment (deforestation, pollution, etc.). With this in mind, it isn't hard to imagine that the trend of global warming (which appears to be a reality) has anthropogenic origins if only in part.

So the question then, is global warming natural, anthropogenic, or both? If both, to what extent either way?

Consider the following argument:

• Global CO2 emissions have increased greatly in the last few hundred years and are strongly correlated to human industrial advances.
• We know that CO2 is a by-product of the use of fossil fuels. Fossil fuels dominate our energy production.
• CO2 has the effect of trapping radiative energy from the Sun, which gets reflected back to the surface of the planet.
• The global mean temperatures are in a rising trend when observational data is analyzed.
• Since CO2 is created through human activity, it can be concluded that human activity is at least a partial cause of global warming.

What weaknesses exist in the premises that lead to the conclusion?

i.e. Syllogisms aren't so scary after all :)

_EW_

I think from a certain point of view any anthropogenic cause is also a natural cause, so the remaining and only relevant question is, indeed, to what extend is the observed course of Earth's climate influenced by the human species in relation to, say, every other species of the whole, wide universe?



The point where we have refrigerators? ^^

CO2 is not the leading greenhouse emission. In fact it plays a relatively small role. Historically CO2 increases follow an increase in temperature, as a greater number of living creatures tends to increase the CO2 levels.

Water vapor is far more effective at trapping radiative heat.

Global mean temp has historically been higher without man's assistance. In fact when it was at it's highest temps the Earth was going through an explosive growth of life.

Correlation does not imply causality. And actually, we are pumping less pollutants into the atmosphere than in many phases of our civilization.

Many of the models of global warming tend to ignore external causes. For example volcanic activity, which pumps as much CO2 into the air as every car running constantly for a year, Solar activity, which has already shown that it has a more dramatic effect on our temperatures.

And the biggest problem with warming is that it makes money. You don't debunk what gets you the grants.

Though not being the leading greenhouse emission, it's still adding its part to a rise of the mean temperature.

Strange, I thought water vapour is usually a result of, err, heat? I mean I'd take a wild guess and claim that the human civilisation is a rather quite exothermic one.

Though not human life, or lifeforms as we know them nowadays. Actually, it appears to be true that we've had higher concentrations of CO2 in our atmosphere, and higher mean temperatures as well. In the past. The distant past, compared to our time here on Earth.

I'm not so sure we'd want to have these conditions back in the here and now.

Again, I think the human aspect of global warming has been so over dramatized that people really need to take a step back.

Water vapor occurs even at relatively low temperatures. Though it does increase as temperatures rise. Anyone who's ever owned a pool can tell you that much.

Cloud cover reflects heat back to the ground. Having spent a few bitter cold nights with no cloud cover to trap in that heat would answer that one.

Meh honestly I'd rather have the warmer temps than the colder temps. It's a lot harder to grow food in a frozen tundra than even a desert with modern water transport

There's more than just vegetables (anyway, diet up North is still mainly based on meat - don't get me started on the anti-sealhunting crap which was mainly started by some ultra-rich actors/singers who don't have to worry about whether or not they'll be able to eat tomorrow.).The houses and buildings which were build on permafrost are currently litterally falling apart and will all have to be replaced in the next 10-20 yrs at most. Polar bears get hungry and are no longer afraid to go looking for a "snack" were they're not supposed to...there are many other consequences too (environmental, political and other).


Just a few recent interesting articles:
http://www.guardian.co.uk/environmen...e-change-poles
http://www.sciencedaily.com/releases...0428154831.htm
http://www.hindu.com/thehindu/holnus...0904281032.htm
http://www.google.com/hostednews/ukp...WQNF6WhGjLH5Tg

Thank you for the very pointed and specific counter-points to anthropogenic global warming. This is, at least, something that can be examined, if not empirically, then rationally.

CO2 is the 2nd most abundant greenhouse gas after water vapor. Water vapor has always been with us, however, and is largely a fixed system (the quantity of water on the planet doesn't increase/decrease in quantities that are noticeable; vapor is relative and, at times, ablative as well as insulating, meaning that cloud-cover can reflect light from the sun as well as insulate radiative heat from the earth (Lindzen 1991; Ramanathan and Coakley 1978). Water vapor is a feedback rather than a forcing agent when it comes to greenhouse gases, this is primarily due to its residence in the atmosphere (about 10 days) when compared with CO2 (about a decade).

Not apparently so due to its albedo effect as well as its trapping effect. Further, since our planet's greenhouse effect is an important and depended upon system where water vapor plays a relatively static and important role in a feedback system, the introduction of the second most abundant greenhouse gas is actually forcing the system, resulting in increased insulation and, thus, increased surface temperatures (Lindzen 2007; Ramanathan and Coakley 1978).

True. However, during this period, the Earth's orbit was slightly different, thus the cause of this natural global warming was astronomical and is not occurring today. Moreover, this "growth period" was just following the Pleistocene and the sudden rise in water levels due to meltwater following the last glacial maximum and a return to warmth from sub-freezing temperatures in the northern hemisphere where these "historically higher" temperatures occurred. In addition, this effect was only in the summer (NOAA 2008).

Correlations do not imply causations, but strong correlations cannot be (and should not be) ignored. The correlation of CO2 increase to temperature increase is not casual based on the long-term trend associated with it. In addition, its demonstrated through empirical data that CO2, the second most abundant greenhouse gas in the atmosphere, results in radiative forcing (Lindzen 2007) where water vapor, the most abundant, does not. It adjusts relative humidity constantly.

What are the data for this? Or is it simply a confidence statement?

Every study I've read so far includes this in the models from which data is derived. Indeed, the effects of volcanic activity include other aerosols than CO2 and it's been demonstrated that volcanic activity actually has a cooling effect (Soden et al 2002). Also, volcanic contributions to the atmosphere is on a decline (Meehl et al 2004).

Shown how and where? The sun always shines. We have an existing system to which new contributors are forcing increases. Why would mentioning solar activity be of consequence?

This is rhetoric and not a reasoned or logical argument. It commits the fallacies of assuming that science has no other research potential beyond climate research; that climate researchers wouldn't be motivated to be the first to demonstrate a new the alternative hypothesis; etc. I see no reason to bother with entertaining such politically motivated and undereducated poppycock.


References:

Lindzen, Richard S. (2007) Taking Greenhouse Warming Seriously. Energy & Environment, 18(7/8), 937-950

Lindzen, Richard S. (1991). Review of: Climate change, the IPCC Scientific Assessment. Quarterly Journal of the Royal Meteorological Society, 117, 651-652.

Meehl, G.A., et al (2004). "Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate". Journal of Climate 17: 3721-3727.

NOAA (2008). The Mid-Holocene "Warm Period." National Climate Data Center, Found online at: http://www.ncdc.noaa.gov/paleo/globa.../holocene.html

Ramanathan, V. and J. A. Coakley, Jr. (1978). Climate Modeling through Radiative-Convective Models. Reviews of Geophysics and Space Physics, 16: 465-490.

Soden, Brian J., et al (2002) Global cooling after the eruption of Mount Pinatubo: A test of climate feedback by water vapor. Science, 296(5568), 727-730.

Ya know.. the conclusions would have more merit if they didn't say there was nothing else to account for the temperature variation

They ignore sunspot activity
http://www.globalwarmingart.com/imag...ot_Numbers.png
another one that seems to kinda mirror the hokey stick graph for temperature change
http://www.globalwarmingart.com/imag...ty_Proxies.png

But there's no other explanation other than man for the temperature change. Nope, none at all.

This is an uninformed statement and not factual. Please cite the study/studies that say this. You can begin by reviewing the ones I've cited already and noting that they do variously discuss sunspot activity and other causes beyond human activity. In fact, the point of several is to determine to what degree human activity plays a part.

Question: are you actually wanting to participate in intellectual and academic discourse on the topic or more interested in tossing out straw man arguments and political soundbites from the undereducated that are somehow threatened by academic inquiry and science?

If your answer is yes, please consider an analysis of the extent to which sunspot activity is a part of recent trend in global temperature increases, taking into account why these trends aren't reflected in past sunspot activity. Then consider ending by taking a moment to comment on the data presented in my last post where you appear to resort to uninformed soundbites that aren't backed by actual science.

Clearly the trend is for warming temperatures which is likely to have detrimental effects on the environment and economy as sea levels rise and agricultural regions experience extended drought. I'm still not sure to what extent human activity plays a part of it, but I still haven't come across data that are suggestive that global warming isn't anthropogenic.

Um... I got that from your own sources. Have you even read their conclusions? Lindsen even says in your first citation exactly what I pointed out.

Do you really want intelligent debate, or are you just going to continue throwing me CiteU babble?

Of course its mentioned in the studies that I cited. But have you actually analyzed the data or are you just comparing pretty pictures? Hint, go to the OP and look at the first graph and note where it says "solar." Compare with the rest.

No one is disputing that solar activity has nothing to do with global temperatures or that it isn't a factor. It just doesn't appear to be a factor as significant as increasing greenhouse emissions.

What I'm critical of is your irrational and uninformed accusation that researchers are considering or discussing causes outside of CO2, which is either an intellectually dishonest or ignorant accusation and I see no middle points to disrupt that dichotomy.

Actual data are lacking in many of the studies. I think I remember even hearing one of the advocates had to provide his data. The computer algorithm used would have produced a hockey stick graph with stock market figures(Not saying they all do this, but it tends to look bad).

You almost seem to be claiming that anyone who does not share the belief in anthropogenic global warming is blasphemous....

One thing I was trying to state(though I think it may have gotten lost) is that it is entirely possible that the correlation between CO2 levels and temperature increase could be related but in the opposite causal relationship. increased temperatures make for more favorable conditions for animal life. More animal life, more CO2. So while CO2 may add to the greenhouse effect, it could be more of an effect than a cause.

Note: I'm quitting smoking, so the brain is functioning weirdly right now... It's threatening to kill my empathy if I don't give in to its demands...

I've been trying to find the answer to this question for about a year now. Thanks you for this!

This will sound harsh, but I divide people into two - those who accept we're causing, or at the very least fuelling, global warming, and those who do not understand the subject. Pardon me, but there seems to be a lot of irrational thinking on the side of the deniers.

No one is saying humans are the only. Warming and cooling of environments have historically been caused by a multitude of factors. This time, however, evidence points to us as the culprit.

I wonder if the first human responsible for a forest fire defended himself with the same logic - "look, Urrg... listen, Aaarr, we've always had forest fires! They're natural! There's a multitudes of causes for them - drought, lightning, the gods... we've always accepted this! But now all of a sudden it's me?!".

Not that I have heard.

This demonstrates again that you're not really familiar with the issue. No one is stating that temperatures will rise continuously everywhere on the whole Earth. Global warming means that the average global temperature will increase over a period of decades. This means that some places will get cooler, which may be just as devastating as warming in other areas. It means that you'll have a cold year here and a snowfall there, but the average temperature will increase. For an illustration, look at this number sequence:

3, 4, 3, 4, 4, 5, 4, 3, 4, 3, 2, 4, 5, 7, 4, 5, 6, 7, 6, 5, 6, 7, 8, 9, 6, 8, 11...

Clearly an increasing trend. The bolded numbers are instances in which the trend seems to have reverse, but looking at the whole sequence, it's obvious this isn't the case.

False.

No, that's the Creationists. Those who deny AGW are witches.

Actually they're called the moral equivalent of holocaust deniers. Witches have a less unsavory rep in this era. ;)

Oh, right. My bad.

I see.. Paraphrasing... You're either in agreement with me, or you're an idiot.

Not at all what I said. I noted how a lot of people who deny AGW seem to not know too much about it. That's a different statement entirely.

I see, Climatologists, Geologists, Meteorologists with doctorates in their fields don't know much about AGW? Admittedly, I'm not an expert in any of the required fields, but then I highly doubt you are either. What I don't like is your false dichotomy. Essentially saying that in order to not believe in AGW you mustn't know about it.

Also considering that Antarctica's Ice concentration has INCREASED over the past 10 years...

http://www.globalwarminghoax.com/e10...ion_extent.jpg

Probably, greenhouse gases caused by common emissions (car exhaust, water vapor, methane, carbon dioxide, etc.) are normal contributors. That's of course only substantial if you "believe" in Global Warming ;)