My apologies in advance for digressing from the main topic at hand. I don't usually participate in debates about US domestic politics, but if somebody attacks science I have to respond. I'll try to keep it short.

Cattivo wrote:

Most republicans, including myself, think Global Warming is a myth, and a scam to authorize the expansion of government.

If you honestly believe that the scientific consensus among the vast majority of climate scientists is somehow manufactured to further somebody's political goal, you're not much better than those wackos who claim that the attacks of 9/11 were an inside job. What you're proposing here is a conspiracy theory and nothing else.

Cattivo wrote:

Any warming we are experiencing is probably due to solar cycles, especially because the polar icecaps of Mars, and even Pluto are also experiencing some fluctuations.

Wrong. Also check out the IPCC FAR Summary for Working Group 1 on page 4. You can clearly see that the contribution of solar irradiance is tiny compared to the net anthropogenic forcings. That means that the sun does of course play a certain role, but the major influence here is GHGs. Solar forcing alone is not enough to explain the recent warming.

Cattivo wrote:

Not to mention the the recent warming cycle ended in 2000, according to recent data.

Wrong again. The trends over the last decade are still positive. If you want a more recent analysis that includes 2008, I took the global mean temperature data from GISTEMP and applied a linear regression. HadCRUT3 would look similar.



As you can see, the warming hasn't ended. Not to mention the fact that you can't draw meaningful conclusions about climate from a ten year period. For this to mean anything we'd have to use at least thirty years of data, and then the results show even more conclusive evidence for warming.

Cattivo wrote:

There are other opinions out there, y'know. Here's the first results of a simple google search, from National Geographic: "Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says"

Notice how Abdussamatov is a physicist, not a climate scientist. I'm sure he knows a lot about the sun, but he is completely out of his field of expertise when talking about the effects that the sun has on climate.

Cattivo wrote:

http://dsc.discovery.com/news/2009/03/02/global-warming-pause.html Notice they're using a 30 year trend, not ten year.

No, they didn't. Did you even read the article? They say "Following a 30-year trend of warming". Nothing about a 30-year trend of stagnation. Then they go on to say "When added up with the other four years since 2001", referring to 2005-2007. So they analyzed a seven, maybe eight year period. Climate is defined as weather over a long period of time, usually thirty years. You cannot draw conclusions about climate from a decade of data. What they analyzed was weather, not climate.

The article also explicitly supports the scientific consensus that GHGs are responsible for a rise in global average temperatures, which you simply chose to ignore:

Discovery wrote:

he warned that it's just a hiccup, and that humans' penchant for spewing greenhouse gases will certainly come back to haunt us. [...]"Thirty years of greenhouse gas radiative forcing will still be there and then bang, the warming will return and be very aggressive."

So what they are saying is that there are currently other factors that are overshadowing the CO2 caused warming, not that the warming is caused by solar irradiance or space monkeys. You're just picking the parts that you like and ignore the rest. That's intellectually dishonest.

We could do this all day, but what it comes down to is this: are there individual scientists that disagree with the consensus on global warming? Yes. You will find that this is true for almost any scientific theory. Is there nonetheless a broad scientific consensus that the climate is warming due to human influence? Also yes.

This leaves two possible responses. We can either stick with the majority opinion like we do in any scientific matter that we can't claim to have expertise about. Or we can choose to ignore the majority opinion based on the assumption that it's all a leftist conspiracy among scientists to rob us of our precious bodily fluids.

One of those is a reasonable position to take. Guess which one.

Syd Lexia wrote:

Our climate certainly seems to be changing, but it is impossible to tell whether or not humans are causing it.

Of course it's possible. That's exactly what science does. If you determine the cause of past changes in climate, if you show that those causes aren't currently happening or not enough to explain the current changes, if you know that CO2 levels are increasing, if you know that CO2 causes a greenhouse effect and if you know that global average temperatures are rising, then you can conclude that CO2 is the major cause for the warming. That's exactly what scientists have done.

Cattivo wrote:

You misread me. The study is comparing the previous 30 years to the past ten. It's a ten year stagnation, not 30.

And that's why it's bogus. As I said you can't draw conclusions from such short time spans. You have to use longer periods, at least thirty years, to cancel out the influence of natural year-to-year or even decade-to-decade variability.

And I don't believe the stagnation claim until I've seen the numbers they used. I applied a linear regression to both the GISTEMP and HadCRUT3 data of the past ten years. Both trends were positive confirming what I've already seen in other studies on the subject.

Cattivo wrote:

There is no consensus.

1. The IPCC has summarized the current consensus in peer-reviewed scientific literature. No original research was done, no consensus was forced, where uncertainties remain those were reported. The consensus they found in the literature was this: (1) Warming of the climate system is unequivocal. (2) Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (90%) due to the observed increase in anthropogenic (human) greenhouse gas concentrations.
2. This was endorsed by numerous scientific organizations. There's not a single scientific body, national or international, that rejects these findings.
3. Oreskes (2004) analyzed 928 randomly chosen peer-reviewed scientific articles about global warming. Not a single one of those rejected the consensus position. That doesn't mean that there are no dissenting voices. But you can infer that with a confidence of 95% those make up less than 0.3% of all scientific papers on the subject.

If that's not a consensus for you I don't know what is.

Cattivo wrote:

UN Blowback: More Than 650 International Scientists Dissent Over Man-Made Global Warming Claims

A quick look at the people who signed this showed a lot of chemists, physicists, geologists. Not everybody who is a scientist is qualified to talk about climate science. Also signature campaigns are not science. Publishing in peer-reviewed scientific journals is. See above for that.

Cattivo wrote:

You really should read more in depth about the other side of the argument. I suggest the pamphlet by the President of the Czech Republic, Vaclav Klaus.

Sorry, but I only read books written by climate scientists about this subject. You know, people who know what they're talking about.

Anyway, I'm going out now. All this arguing has made me thirsty. Time for a beer.

Tyop wrote:

Cattivo wrote: UN Blowback: More Than 650 International Scientists Dissent Over Man-Made Global Warming Claims A quick look at the people who signed this showed a lot of chemists, physicists, geologists. Not everybody who is a scientist is qualified to talk about climate science. Also signature campaigns are not science. Publishing in peer-reviewed scientific journals is. See above for that.

Addendum: I took the time to have a closer look at the signees. The list is even more padded than I originally thought. Not only is it full of scientists like chemists, physicists, geologists or even paleontologists(!) that do not actually work in climate science. It's also full of economists and non-scientists, like TV weatherman Steve Baskerville, Weather Channel founder John Coleman or futurologist Ray Kurzweil. Not to mention there's a number of people who don't actually disagree with the IPCC consensus, like Kurzweil or meteorologist George Waldenberger. Here's what Waldenberger had to say about this (back in 2007 when the list had 400 signees):

Waldenberger wrote:

Take me off your list of 400 (Prominent) Scientists that dispute Man-Made Global warming claims. I've never made any claims that debunk the "Consensus". You quoted a newspaper article that's main focus was scoring the accuracy of local weathermen. Hardly Scientific ... yet I'm guessing some of your other sources pale in comparison in terms of credibility. You also didn't ask for my permission to use these statements. That's not a very respectable way of doing "research".

In conclusion this list provides everything except evidence for the claim that there is major disagreement about global warming among climate scientists. It does however provide a good number of laughs.

Syd Lexia wrote:

We have strong theories as to climate changes that have happened in the past and why they happened, but we can't definitively prove them. It's the same reason that evolution is considered a theory instead of a law.

RobotGumshoe already explained why your claims about theories and laws in science are wrong, but I recommend that you watch this video of scientists explaining the matter, because it goes into a little more detail.

More specifically your claim seems to be based on a misunderstanding about how scientific theories are tested (not "proved" as you say, cf. Popper). The fact that you can't directly observe something that happened in the past doesn't mean that you can't test it. As with any scientific theory you can extract hypotheses that can be verified here and now.

For example you can't directly observe the Big Bang. But you can test for the cosmic background radiation that is predicted by the theory. You can't directly observe the evolutionary changes of the past, but you can test for the predictions about genetic relations and intermediate fossils that the theory delivers.

Likewise you can test predictions derived from theories about natural climate change of the past. Here's an account of how the theory of Milankovitch cycles which explains the onset of the ice ages was first tested:

Quote:

Evidence supporting Milankovitch’s theory of the precise timing of the ice ages first came from a series of fossil coral reefs that formed on a shallow ocean bench in the South Pacific during warm interglacial periods. As the ice ages came, more and more water froze into polar ice caps and the ocean levels dropped, leaving the reef exposed. When the ice melted, the ocean rose and warmed, and another reef formed. At the same time, the peninsula on which the reefs formed was steadily being pushed up by the motion of the Earth’s shifting tectonic plates. Today, the reefs form a visible series of steps along the shore of Papua New Guinea. The reefs, the age of which was well-defined because of the decaying uranium in the coral, measured out the millennia between ice ages. They also defined the maximum length of each ice age. The intervals fell exactly where Milankovitch said they would.

The "thousands of years worth of data" that you claim we don't have is still there. It's just not as obvious to you as it is to a scientist.

Of course none of that means that at any time our knowledge is 100% correct. But that's true for any scientific theory, whether it concerns the present or the past. We could directly observe Newtonian physics in action and it still turned out to be "wrong" and was superseded by Einstein's theory. If you demand perfect proof then no scientific theory is ever going to satisfy you.

Syd Lexia wrote:

Also, the idea of global warming, is a misnomer. The more acceptable term is global climate change

Eh, not really. The Oreskes paper that I mentioned above used the occurrence of "global warming" in paper abstracts to select the random sample. The term is well-established in the scientific literature to specifically describe the recent rise in global average temperatures caused by GHGs.