The only good that can come from a thread like this is LeonWalras.

Seriously though, there is no point trying to debate this issue, unless you enjoy a pointless argument. Neither side ever listens to the other.

... So it's a debate.

I'm not asking for what or why they think what they think, just what is the necessary threshold of argument, or evidence, or whatever that would convince them to change their mind.

The titanic isn't sinking! My end is 20 feet up in the air!

What evidence could a "climate change denier", more specifically a "man is the primary cause for climate change" denier, show you that would convince you that man plays a much smaller role in climate change than leading scientists are claiming?

primary cause *of* climate change would be more accurate

@y2kjbk - Get 50% of Climate scientists to state that they see evidence that the Climate change we are undeniably seeing is the result of natural forces, and I'll entertain the debate.

@Puddle - there is one problem with your statement. "could be affected by actions that we could take currently". Some Climate scientists say it's too late to affect what's going to happen the rest of this century, and that the correct response is to find out how we're going to live with the disasters that are now inevitable. Radical chances made now might keep it from getting any worse than what they say is inevitable.

well what do scientists point to that indicates humans are the primary cause for climate change? is it always extra CO2 in the atmosphere? how rigorous is the proof that CO2 is the leading reason for a warmer atmosphere and that humans are the primary cause for it? more data beyond "it's obvious we're always burning shit" is appreciated. The issue with that is that our data collection is pretty thorough today I believe, but a lot of it is incomplete and fudged for earlier years. That's where many believe somewhat rationally that scientists often take the liberty to estimate past statistics to promote the cause that humans and the industrial revolution started us down this road that we wouldn't be going down otherwise.

I'm not sure why anyone believes man is the primary driver of climate change. Man has been burning fossil fuels for less than 200 years and releasing large amounts of CFCs into the atmosphere a lot less than that but the earth has been through several Ice Ages (with estimated global temperatures 8-10 degrees C cooler than current as opposed to the < 1 degree C rise in temperatures observed over the last 130 years). The earth has also been through significantly warmer periods than current with estimated temps 4-5 degrees warmer C. To me it shows a lot of hubris to assert that man is the primary driver of climate change when there is a long track record of climate change on earth long before man existed let alone started burning fossil fuels. Do Anthropogenic Climate Change fanatics/champions/believers think temps would remain constant on earth if not for man burning fossil fuels? How do you completely disregard the historical record like that?

Because if they don't blame humans then they can't use "climate change" as a pretext for governmental restrictions on individual liberty.

Right and they also wouldn't be able to make lots of money off of it. Certainly Al Gore has done well for himself by championing Anthropogenic Global Warming.

@y2kjbk Where's your evidence that it was fudged for earlier years? And don't use the emails - that was clearly blown way out of proportion. They did NOT say that they fudged the data.

@Yaleunc There has been cyclical, historical climate change. But never at the speed and acceleration of the last century. And CO2 levels are at levels that have NEVER been seen since Earth created a biosphere with plants and animals. Climate Change SCIENTISTS (not fanatics), who believe the data they see, see the effect of human action on what should be a gradual change.

It comes down to this. Scientists had this debate decades ago, as it should be - theories were proposed, disproved, new theories were then proposed, experimental results were duplicated and confirmed, and now 97% of Climate scientists have been convinced BY THE SCIENTIFIC METHOD that Climate change is real and is caused by human action. So why do people argue with them? Because our leaders are paid by the energy companies to cast doubt on the science for short term profit.

There is no scientific debate. There is political debate, and real questions about how we need to react. But the scientific consensus is - we need to do something, and fast.

Also, I'd like to hear more from Puddle about what he means in his third assertion (threat to human habitation and civilization). We survived ice age conditions and significantly colder temps but we won't be able to survive global increases of 1-2 degrees C over the next several centuries?

Right and they also wouldn't be able to make lots of money off of it. Certainly Al Gore has done well for himself by championing Anthropogenic Global Warming.

Sorry for reposting that one, my browser was hung. @jbalcorn, the 97% figure you cited is not climate scientists that believe man is the primary driver of climate change. Over 9k climate scientists with PhDs and another 7k with Masters degrees signed the Oregon Petition Project disputing that man is the primary cause of climate change.

I'm with Yaleunc.

As far as I'm concerned, the biggest idiots are those who believe climate change isn't real. The ones who believe climate change is completely man-made are second and the ones who believe humans have nothing to do with climate change are third in my mind.

@jbalcorn - I think your comment betrays some naivete. Do you really think scientists are immune from political pressure? Scientists have agendas, governed by political and economic convictions just like anybody else. There's plenty of "data" that could support any position. It just takes a little sculpting. You know that from playing diplomacy. Are we to pretend that scientists really always just "follow the scientific method, wherever it leads" and not to acknowledge that just like everyone else they rig the experiments to reach the conclusions that they desire?

The smartest ones are those that admit they have no fucking idea what's going to happen to the earth in the next two centuries, for good or for bad.

@y2kjbk I'll try to answer your questions in what I assume is the same spirit that they were asked.

(1) How do Scientists determine that humans are the cause of the change?

So I'm not going to dig into specific data here because the specific data for most individual studies differs. Instead I'll provide the methodological framework for these findings. It's important to acknowledge and explain past climate change activity (geologic time frame, so past=everything before humans). In the past any phenomena that occurred was “natural” in the sense that is was not man-made, this does not mean that the climate cycled consistently or predictably. While some climatic events, such as the desertification of the Sahara, are likely due to cyclical events such as the wobble in Earth’s axis, most sudden climactic shifts occurred either due to a major geologic event or an impact from another body. It is usually through the effect these events have on the composition of the atmosphere that determines the effect on the climate.

So the way that scientists have found that human activity is the cause for the current shift in greenhouse gases is by examining the period of which the increase has occurred to look for the cause. During the period in which greenhouse gases have risen at unprecedented levels, there have been no major “natural” events that could account for this. Comparatively human activity once accounted for explains nearly all of the increase. So in essence greenhouse gases rose by X amount over the period concerned; natural phenomena account for an increase equal to N; human activity accounts for increase equal to H; N + ? = X; ? = X - N; X - N = H; H = ?. Through this process scientists came to the reasonable conclusion that H accounts for the increase in greenhouse gases beyond the increase caused by natural phenomena.

@y2kjb: Agreed. I'm in that camp. I guess I didn't exactly make that clear.

@Yaleunc There are several ways that climate change threatens human civilization and habitation. I am not nearly as worried about extinction, but there is a small danger of that as well.

So by civilization I mean the current civilization. Assume that the estimates which are no being proven overly conservative are correct. In such a scenario there are two big pressures on resources, the first being the refugee and displacement problem of most major cities become at least partially flooded, the second are the inevitable wars that will result either as a direct result of the refugee movements (as in physical relocation) or as a result of the secondary resource scarcity problems caused by the refugee problem. Between the loss of major cities and the refugee status of hundreds of millions of people, and the result of war I can not imagine that current global commercial activity could continue to function. Even regional (such as intra-US continental trade) are likely to be disrupted. The modern civilization depends on both long supply chains which allow geographically disparate people and resources to cooperate, and the constant production of those people and resources. Even a relatively short breakdown (3-5 years) of the global trade and transport system is likely to cause irreparable harm to existing order. This will result in more war as delicate regional stability collapses and states break apart or compete for near resources.

The threat to human habitation is more localized issue, I mean specifically the loss of large stretches of land either to the sea or to inhospitable conditions. Also the relative level of global habitability will diminish. The loss either of arable land, watersheds with which we have turned arid to arable land, or the means to transport and preserve food over large distances and times, will mean that for most nations their current population will not be sustainable.

The threat of extinction lies mainly in our response, if we descend into chaos and war there is an uncomfortably large chance of nuclear weapons being used in a war, and along with that the threat of an contained nuclear war.


I would agree that these kind of worst case scenarios are avoidable and likely will be averted to some degree, but a lot of that comes down to when and how we respond.

"overly conservative"?

" Over 9k climate scientists with PhDs and another 7k with Masters degrees signed the Oregon Petition Project disputing that man is the primary cause of climate change."

In 1998, 1400 PhDs in Climate Science signed the petition. the 9k number included other scientists. That's when there was debate. VERY many of those have changed their minds.

threadID=1200943

First page, first reply.

@Mahar-Shalal-Hash-Baz While there is certainly a degree to which personal bias will effect any given researcher, it is very difficult for such bias to effect the entire scientific community. In part this is because Scientists to not ascribe to any single religious or political belief. This means that at the very least there are competing biases which should in the aggregate neutralize one another. The second and more powerful reason is because of how peer review works. The peer review process includes not only other scientists scrutinizing the conclusions you drew from the experiment or research, but also the methodology of your work. This includes things like examining the data itself and how it was collected, whether the hypothesis that is being tested even applies to the theory, and whether or not your results can be repeated. The fact that experimental scientific work has to be repeated in order to be truly confirmed makes the chance of outright fabrication due to bias remote.

Further the examination of the hypothesis, as well as the way hypothesis are formulated also make bias hard to artificially introduce. The hypothesis that one tests should be formulated in such a way that one's efforts are aimed not at proving something but disproving something. Science reaches a conclusion on something not via an affirmative confirmation method, but via a negative elimination method. Once all possibilities have been tested and the scientific community reaches a consensus that no new idea to disprove a theory has been proposed a consensus is reached and scientists largely move on to other questions. This does not preclude someone coming up with a whole new idea and disproving a theory later though, and doing so is one of the best way to become famous as a scientist.

@Yaleunc take a look at this, the source for the 97% claim. Feel free to read the whole article, but I've included the abstract below, it contains the pertinent information.
http://iopscience.iop.org/1748-9326/8/2/024024

I just did a little research on the mentioned Global Warming Petition Project and that seems like a good place to start for those who think the refugee status of hundreds of millions and inevitable wars and so on are a moderately estimated consequence of "overly conservative" estimates.

That's just an outright lie.

Here's that abstract:

We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. In a second phase of this study, we invited authors to rate their own papers. Compared to abstract ratings, a smaller percentage of self-rated papers expressed no position on AGW (35.5%). Among self-rated papers expressing a position on AGW, 97.2% endorsed the consensus. For both abstract ratings and authors' self-ratings, the percentage of endorsements among papers expressing a position on AGW marginally increased over time. Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research.