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http://skepticalscience.com/going-down-the-up-escalator-part-1.html

Also you're comparing geological time-scale climate change with dramatic recent climate change. Answers for your questions exist, even if you don't wish to see them.

I love an alarmist, panic-in-the-streets, headless-man-found-in-topless-bar, headlines as much as the next guy, but the Keeling Curve has been hitting 'record levels' every year since the late 1950s.

Yeah well, believe it or not one of the common arguments I face when talking about man made CO2 is that human emissions are nothing compared to natural forces of CO2 and a similar argument is that the Earth has a natural cycle that keeps this level of CO2 in balance and in check.

So as we watch CO2 levels steadily rise, it gives us insight into how much of these "natural processes" are effecting greenhouse gases in our atmosphere versus what we are contributing to these levels. And I think it's important to remind people that 1) these levels are steadily rising so no, the Earth is not keeping itself in check, 2) it's not just something where turn on the "remove CO2 machines" to fix it and 3) if natural processes are the cause of these levels of CO2, where is the corresponding increase in these natural processes?

Seriously people tell me all the time that one volcanic eruption dwarfs anything man could do in a decade. And I don't know where they get this shit. So tell me, where are all these new volcanic eruptions to explain this steady trend upward? Oh, we can't report that it's rising because you feel offended that it's "alarmist, panic-in-the-streets, headless-man-found-in-topless-bar, headlines." With all due respect, you're not helping this situation!

Maybe I should've linked to the Basic page instead. The Intermediate page seems to have bounced off you.

Stefan-Boltzmann still applies, of course - warm bodies radiate energy - but it says nothing about a warm body's ability to absorb radiant energy, even if produced by colder bodies. This is where you're going wrong. Warm bodies radiate faster than cool bodies (that's thermodynamics), but cool bodies still radiate some energy, which can of course be absorbed by the warm bodies, slowing their rate of cooling. Is this not intuitively obvious? It's certainly long-established science.

Let me break down the atmospheric situation for you, in simple language: Greenhouse gases reflect & absorb certain IR bands of sunlight,but pass higher bands, like visible light. The sunlight that gets through warms the Earth, which radiates it back in the IR bands, according to Stefan-Boltzmann. Those same greenhouse gases now reflect & absorb the IR coming from the Earth as well - trapping much of the heat that would otherwise have radiated into space.

This process is in complete accordance with thermodynamics, and has been observed and proved to virtually everyone's satisfaction long, long ago. If Latour still labours under the belief that he can challenge this, he can attempt to publish a paper, but I predict his methodology will be torn to shreds by reviewers far more capably than I could manage.

Latour is a chemical process engineer trying to explain thermodynamics to a climate scientist. His "rebuttal" is full of basic misunderstandings and laughable examples (that headlights example still makes me grin). He flatly declares (without backing evidence of course) that warmer bodies cannot possibly absorb any energy from cooler bodies (guess what? it slows cooling!), which directly contradicts nearly two centuries of well-established greenhouse theory and countless observations (starting with Fournier in 1824). He does not even try to address the primary issue of disparate absorption of thermal radiation from the Sun and Earth. And he then has the gall to accuse climate scientists of not understanding the difference between radiation and convection.

When (to cut through the misunderstandings) Spencer offers him a simple observational experiment he can do himself to prove the theory, he dodges it and accuses Spencer of shifting the goalposts. It's no wonder Spencer (a practicing climatologist with better things to do) didn't bother to engage further.

If you still think greenhouse theory is nonsense, read this. If you think greenhouse theory somehow violates thermodynamics, read this.

Latour is a chemical process engineer trying to explain thermodynamics to a climate scientist. His "rebuttal" is full of basic misunderstandings and laughable examples (that headlights example still makes me grin). He flatly declares (without backing evidence of course) that warmer bodies cannot possibly absorb any energy from cooler bodies (guess what? it slows cooling!), which directly contradicts nearly two centuries of well-established greenhouse theory and countless observations (starting with Fournier in 1824). He does not even try to address the primary issue of disparate absorption of thermal radiation from the Sun and Earth. And he then has the gall to accuse climate scientists of not understanding the difference between radiation and convection.

When (to cut through the misunderstandings) Spencer offers him a simple observational experiment he can do himself to prove the theory, he dodges it and accuses Spencer of shifting the goalposts. It's no wonder Spencer (a practicing climatologist with better things to do) didn't bother to engage further.

If you still think greenhouse theory is nonsense, read this. If you think greenhouse theory somehow violates thermodynamics, read this.

Al Gore promised us a hockey stick spike in temperatures and he was flat wrong.

You do realize that 2100 and 2012 are not the same year, right? The hockey stick doesn't predict temperatures it charts historical temperatures. The original one went from rought 1400 to present (at the time, 1999). The IPCC reports, however, predict a rise of around 0.2 degrees per decade. As far as I can tell Al Gore's predictions in an Inconvenient Truth were all further out than 2012. His predictions haven't come true because we haven't reached them yet. It's kind of like you're castigating someone who told you electric cars would be everywhere in 2040 because they're not everywhere right now.

In the last 16 years, you cannot say that the trend he predicted came anywhere close to being accurate.

Climate modles predict that we will occasionally have decades where the temperature slope appears to be 0. It's a consequence of noise in the data. We've had quite a few of these flat periods in the past too, yet the average temperature keeps rising. Skeptical Science has a blog post explaining the problem with this.

All the schemes to add carbon taxes, reduce drilling, oppose oil shale development, fracking, and kick back schemes to promote "green energy" are just fleecing taxpayers and making the economy weaker.

Actually, carbon taxes tend to be economically neutral to good. They encourage the reduction of CO2 emissions, and the money gets either refunded to tax payers who then spend it, or spent by the government on infrastructure projects. Both of those activities may actually stimulate the economy more than what the money would have otherwise been spent on (like raises for company executives).

As I understand opposition to shale development and fracking has a number of reasons, most of which are not global warming related. It seems people don't like poisoned water supplies and earthquakes. Who knew?

The total subsidies to green companies are actually still much lower than the subsidies offered to coal, gas and oil companies. I don't know why extremely profitable companies that pollute the land and air are beeing given tax payer money, but I'd start looking there if you want to figure out who's fleecing you.

2 and 3x increase in energy prices create poverty, inflation, higher unemployment, and more dependency on the government.

It will indeed, however, it's also unavoidable. The easy to access energy is gone, every year the cost to get the next barrel of oil out of the ground increases. It's only a matter of time before oil is the expensive, dirty option instead of the cheap, dirty option.

But we can disagree. Turn off your computer, you're burning carbon.

Actually, most of my power comes from hydro-electric or nuclear power.

Name one that has come true, if you can.

"The world will get warmer."

Proof: Domingues 2008, Nuccitelli 2012, NASA GISS, NOAA NCDC, Hadley Centre, and BEST 2011 (preliminary).

Your posting bullshit:

http://www.skepticalscience.com/global-warming-stopped-in-1998-intermediate.htm

No folks, AGW did not stop in 1998.

The BEST study confirmed that the heat-island effect is "nearly negligible". That link has a good discussion of the analysis and related criticism.

If you read the next paragraph of my original link, you'll see that the BEST heat-island paper in particular was "technically rejected", but was encouraged to re-submit the paper with suggested changes that do not affect the basic results. There is no reason to doubt their analysis at this time.

Unless of course you are in the habit of automatically distrusting anyone who says something you don't like, as it appears. It's ironic that you accuse them of propaganda for releasing their results before full peer review, as Watts and most other deniers have been doing exactly that all along.

As for the BEST dataset, it's been available for many months. As has the data of the other major studies, all of which agree. How many more lines of evidence do you need?

The BEST study confirmed that the heat-island effect is "nearly negligible". That link has a good discussion of the analysis and related criticism.

If you read the next paragraph of my original link, you'll see that the BEST heat-island paper in particular was "technically rejected", but was encouraged to re-submit the paper with suggested changes that do not affect the basic results. There is no reason to doubt their analysis at this time.

Unless of course you are in the habit of automatically distrusting anyone who says something you don't like, as it appears. It's ironic that you accuse them of propaganda for releasing their results before full peer review, as Watts and most other deniers have been doing exactly that all along.

As for the BEST dataset, it's been available for many months. As has the data of the other major studies, all of which agree. How many more lines of evidence do you need?

- an entire book on the subject

And is the book any good? I don't want to bother with it, if it's going to be a waste of my time. Glancing through reviews of the book, it doesn't sound that impressive. A favorable review has this as the bold claim, Exxon Mobile spending millions, but not a lot of millions to protect its business.

The fossil fuel industry, who have poured millions of dollars into PR campaigns to confuse the public. Over 8 years, the most profitable company in history, Exxon Mobil, gave $16 million to think tanks that deny global warming science. Fossil fuel companies also give millions of dollars to politicians such as Joe Barton and James Inhofe, who vehemently oppose climate action.

- Greenpeace, for whatever their word is worth, claiming that the Koch brothers have donated over $61 million to the cause of denying global warming.

Doing that google thing, I see that $61 million is a mere six years funding of the US branch of Greenpeace. The World Wildlife Fund has $180 million in funding last year of which $44 million came from government sources. No anti-AGW group has that sort of funding.

So what we have is a "well-funded" campaign that is vastly outspent just by government contributions to a single non-profit. Ever wonder why the "climate denialists" get any traction at all? It's not the money they're spending. That's for sure.

Manmade CO2 emissions are much smaller than natural emissions. Consumption of vegetation by animals & microbes accounts for about 220 gigatonnes of CO2 per year. Respiration by vegetation emits around 220 gigatonnes. The ocean releases about 332 gigatonnes. In contrast, when you combine the effect of fossil fuel burning and changes in land use, human CO2 emissions are only around 29 gigatonnes per year.

You're right that volcanism is a very small modern source of CO2, but human activity is still a very small minority of global output. Choosing to use volcanism as the comparison is misleading at best. The science is conclusive in favor of global warming, so accuracy and facts are enough to combat bad conclusions.

We add an additional 4% each year and there is nothing to balance that. We can also look at isotope ratios (fossil fuels are ancient carbon). It is our CO2.

http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions-intermediate.htm

Not this again...

Antarctic sea ice is expanding, but Antarctic land ice is shrinking fast.

What's happening is that the ice is slipping off the land and into the sea. So of course there's more ice in the sea, at least until it melts (which it will, since the southern ocean is getting steadily warmer despite the increase in ice).

Expanding Antarctic sea ice is not a good thing. In fact, it's far, far worse than declining Arctic sea ice.

Let's be clear. The people equating statistically improbable disasters - asteroids, aliens all that- to the absolute certain fact that global warming will, if left unchecked for too long, deconstruct civilization are engaging in a type of self soothing via fuzzy thinking. This is what denial is.

The people denying that the threat is imminent and reasoning that it is therefore amenable to current political processes are doing something a little more subtle.

They are creating an imaginary causal linkage between three phenomena which are, in reality, causally unlinked. This is therefore a type of magical thinking.

The first phenomena is the pace at which global warming will proceed. No one knows with certainty how quickly it will proceed or what effects each step of the progression will have on factors effecting national security. What we do know is it's worse than we thought, proceeding faster than we projected.

http://thinkprogress.org/climate/2009/02/23/203730/mit-doubles-global-warming-projections/

That pace is in no way related to the second phenomena , the ability of a (gerrymandered) minority of politicians to block urgently needed action at the federal level. Funded by and beholden to the now-classifiable-as-genocidal gas and oil industries, scientifically ignorant and proud of it, the pace of warming is in no way effected by their continued inaction, and nothing about their inaction obliges global warming to back off for our collective sake.

http://thinkprogress.org/climate/2009/03/17/203822/media-copenhagen-global-warming-impacts-worst-case-ipcc/?mobile=nc

The third phenomena is what level of ecological disaster is going to serve as the trigger point at which the denier population capitulates to reality and assents to urgent, sweeping federal action. Because that level of ecological disaster both exists and will be realized sooner or later.

But that point is in no way causally related to that other point in time, the point of no return, where given our then-current or achievable level of technology, we'll still be able to limit the effects of global warming in order to preserve the habitability of the planet.

There's nothing to say that deniers won't come around too late. There's no guarantee that the level of ecological disaster sufficient to finally get through to deniers will appear on a schedule sufficient for us to solve the problem.

http://www.skepticalscience.com/print.php?r=349

To think vague things like- eventually everyone will come around and then the political process will kick in in time for us to save ourselves- is magical thinking. The forces controlling the pace of, and political resistance to, global warming are unrelated with respect to the time frame needed to act.

The original question is rhetorical but only in the way opposite to that asserted by the deniers here. It IS a fact that the threat posed by global warming falls under the purview of the executive branch who WILL be empowered and in fact have a duty to act unilaterally, without Congressional oversight or approval, in order to preserve the national security of the United States. The only question is when will that time come and how will we know it? Is it now? A little while from now? When it's too late to do any good?

We just squeaked by an election in which one of the parties' candidates was threatening to pipeline in tar sands from Canada and light them on fire. We already know that, if we light on fire all the oil we current have already drilled and sitting waiting to be sold, it's game over for the environment and ourselves. Drilling for more, spending money to obtain yet more and dirtier oil and th

http://www.skepticalscience.com/pics/SkepticsvRealistsv3.gif

Seriously, you're being an ass. I've read through this page of threads, and you've made numerous posts including mistakes of judgment that come across as lies; and then you insult your potential audience. You may have good points, but they are lost or devalued by your tone and approach. Simply as a style of argumentation, your posts wind up more alienating than convincing. This is not the way to bring people over to your way of thinking.

For others, this video evidence that rs79 posted in the GP is a talk hosted by the Sydney Institute. The Sydney Institute itself may or may not be pushing a conservative anti-AGW agenda; at any rate, Gerard Henderson is Executive Director and his wife is the Deputy Director (staff roster), with some online commentators describing them as "neocon" in their views. Gerard Henderson was an adviser to former Australian PM John Howard, whose general political leanings were quite close to those of George W. Bush.

In short, the source is a bit suspect.

The talk itself is about an hour long. I haven't listened to the whole thing yet, but the speaker is Murry Salby, professor of environmental science at Macquarie University in Australia and the university's Climate Chair (university staff page). His basic argument is that global temperature controls CO2 levels, not the other way around. His views are somewhat controversial, perhaps unsurprisingly, and are discussed and refuted to some extent in numerous articles at Skeptical Science, among other places.

...

In all fairness, I could probably dissect most arguments similarly and dig up links to this or that refutation. However, my point here is not to try to claim that Salby is wrong -- I don't know that, and I don't have the educational background to make that judgment. My point, instead, is that Salby's views do not appear to be the authoritative end-all-and-be-all slam-dunk finishing end to the argument of whether humans are responsible for global warming.

Cheers,

Nobody is debating that it's occurring. What is being debated is the egocentric claims that humans are significant enough to upset the CO2 balance of the entire planet... while they're releasing measly 0.04% of all CO2 being released into the atmosphere naturally every year... which is what 29,000,000,000 tons of CO2 into 5,000,000,000,000,000,000 tons of atmosphere? I included all the zeros so it's easier to comprehend without doing the math, but that about 0.0000006% of the atmosphere. citation.

Here ya go: http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm

Where's the CO2 released from the melting icecaps in that handy diagram? What if it's not an effect, but rather the cause of the CO2 increase in the atmosphere?

These nut jobs who proclaim global warming and cite all kinds of fabricated or exaggerated "evidence" are the same nut jobs who were proclaiming a global ice age when I was growing up.

Then it's a good thing that the consensus of peer-reviewed research when you were growing up was not in favor of a global ice age.

http://www.skepticalscience.com/ice-age-predictions-in-1970s-basic.htm

At the same time as some scientists were suggesting we might be facing another ice age, a greater number published contradicting studies. [...]

By 1980 the predictions about ice ages had ceased, due to the overwhelming evidence contained in an increasing number of reports that warned of global warming. Unfortunately, the small number of predictions of an ice age appeared to be much more interesting than those of global warming, so it was those sensational 'Ice Age' stories in the press that so many people tend to remember.

Image in the article shows that of the studies from 1965 to 1979, 62% predicted warming, only 10% predicted cooling. 28% undecided.

You are off by three orders of magnitude, it's more like 29 billion tons. Twit.

That's only true if you've only read a subset of the literature.

Surprise! The man who demands citations at every turn is an arm-waver who never provides any actual information in any post...

Say, you wouldn't happen to have a number that expresses what percent of CO2 man is responsible for would you? That should be easy to get if we know so much about CO2 now.

Here ya go: http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm

[Citation needed]

There's nothing in the moderating FAQ that says it's against the rules to downmod for being wrong, just for disagreeing, which is not the same thing.

I would say "disagree" is a broader category than wrong. It's basically the psychological state of thinking that something is wrong which can happen both when it's wrong and when you yourself are wrong and disagree with something which is right. In both cases you shouldn't down mod for just because you think something is wrong.

However, there's a huge difference between being wrong and being boring and repetitively wrong. When someone posts something new and interesting about global warming scepticisim; that means for me something I haven't heard before; I will never mod it down. When someone posts something stupid like "temperatures have been going down recently" then I expect them to post a link to one of the stronger and clearer explanations of why that's wrong and then explain something new and interesting. Five years ago that might have been something about selective use of weather stations. Now you have to also debunk the statistical analysis that shows that this was actually wrong

If something is wrong, definitely don't mod it up. You can never be sure why the person was wrong and there are plenty of other people who will do that if they find it interesting. If you remember clear debunkings of that information on Slashdot before even in a different article and there's nothing new in the new comment then it's boring and not advancing the debate. You should mod it redundant.

It's useful to look at longer time periods:
http://skepticalscience.com/still-going-down-the-up-escalator.html

Seems like you never heard about the null hypothesis. Weather disasters rack up no matter what and none of what we have seen is in the least out of line with what has happened in history.

oOOooOOoo the "null hypothesis". You must think that 1000s of scientists don't know something about elementary experimental design! That MUST be it! Gee, you could use statistics and evidence to draw conclusions as to the likelihood of various hypotheses. Mmm, let me see... that EXACTLY what that IPCC did!!

Sorry, it might not mean shit to you, but null hypothesis (as you put it) was rejected in a 1979 NAS report (30 years ago). Today, the evidence is just stronger.

If you ignore history, however, you'll always think things are going to hell in a handbasket ... as people have done all the time in history.

Like the history of increasing weather disasters!

Of course I'm wrong, along with the scientific community. You just gotta find the logic to connect the dots.

http://www.skepticalscience.com/Mikes-Nature-trick-hide-the-decline-advanced.htm

Phil Jones' email is often cited as evidence of an attempt to "hide the decline in global temperatures". This claim is patently false and demonstrates ignorance of the science discussed. The decline actually refers to a decline in tree growth at certain high-latitude locations since 1960.

Tree-ring growth has been found to match well with temperature and hence tree-rings are used to plot temperature going back hundreds of years. However, tree-rings in some high-latitude locations diverge from modern instrumental temperature records after 1960. This is known as the "divergence problem". Consequently, tree-ring data in these high-latitude locations are not considered reliable after 1960 and should not be used to represent temperature in recent decades.

The divergence problem has been openly discussed in the peer-reviewed literature since 1995 when it was noticed that Alaskan trees were showing a weakened temperature signal in recent decades (Jacoby 1995). This work was broadened in 1998 using a network of over 300 tree-ring records across high northern latitudes (Briffa 1998). From 1880 to 1960, tree growth closely matches temperature measurements. However, the correlation drops sharply after 1960 for certain trees at high latitudes.

Mods, feel free to mod parent down not because you think he's wrong, but because he is wrong.

Right, but things like this make me doubt the 'scientific consensus':

It's important to understand the denominator when looking at these kinds of lists. You have 100 people with a PHD that doubt the consensus. Over 34,000 science doctorates are turned out each year. The Intelligent Design people put out these kinds of lists as well. They are meaningless when you consider the denominator.

One series of these e-mails called out the journal Climate Research, which had the audacity to publish a paper surveying scientific literature that didn't support Mann's claim that the last 50 years are the warmest in the past millennium... Editors resigned.

There is a very good reason that they resigned. It became clear that the journal was the victim of 'pal review' - http://www.skepticalscience.com/print.php?r=427 . Basically Pat Michaels was submitting papers directly to his CATO institute colleague and free market sympathiser Chris De Fraitas which were then rubber stamped. These papers were easily shown to be bunk and made the journal a laughing stock. The chief editor resigned saying that certain Climate Research editors were systematically publishing methodologically flawed papers.

That article I linked gives an explanation as to how 1) water vapor is far more effective a 'greenhouse gas' than carbon dioxide

This is not unknown to scientists, and is specifically why scientists are worried about Carbon. Added carbon will heat the atmosphere. A warmer atmosphere will hold additional water vapour. Additional water vapour will warm the atmosphere... etc. This is what is known as a feedback. Currently there is about 4% more water vapour in the atmosphere due to atmospheric warming.

and 2) carbon dioxide levels rise after the globe warms up, not before. The argument sounds credible to me.

This is only half true. Carbon levels will rise when the globe warms, but of course it can also rise for other reasons such as the burning of fossil fuels. BTW, a hotter world will release more carbon into the atmosphere which will warm the world... looks like another feedback.

Did you read the Super Freakonomics chapter about global warming? It says that just 20 years ago people were complaining that we were entering a cooling period and we had to do something to warm the globe up.

We have a survey of the literature from over 20 over years ago called the IPCC FAR. http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_08.pdf . The conclusion was: "Global mean temperatures have increased by 0.3 - 0.6 C over the last 100 years. The magnitude of this warming is broadly consistent with the theoretical predictions of climate models." Looks like the Freakonomics guys are out to lunch.

Hint: There's a reason people are starting to call it "climate change" now instead of "global warming".

To a scientist these mean different things. They use Climate Change when they are referring to changes in climates, and global warming to refer to the warming of the globe. Politically though it was Republican strategist Frank Luntz who suggested using Climate Change rather than Global Warming because it sounded less scary: http://www.ewg.org/files/LuntzResearch_environment.pdf

Because stuff like the ClimateGate emails makes it seem like a lot of those 'experts' care more about being right

Science is fiercely competitive. Of course they care about being right. It's a meritocracy.

The Arctic has lost around 3x what the Antarctic has gained - so the answer to your question is "no", no balance. http://www.skepticalscience.com/arctic-antarctic-sea-ice.htm

Somehow my links didn't make it into the post.

CO2 and CH4 concentrations in the atmosphere: http://www.skepticalscience.com/methane-and-global-warming.htm

CO2 and CH4 lifetime in the atmosphere: http://www.guardian.co.uk/environment/2012/jan/16/greenhouse-gases-remain-air

This is redundant, there's already a post above this one and one below this one which say the same thing. And all of them are misleading because they fail to grasp the difference between land ice and sea ice.

Apparently the parent does not understand the difference between sea ice and land ice. http://www.skepticalscience.com/antarctica-gaining-ice.htm

Ice mass is decreasing while sea ice is increasing. The effects are connected, and both result from the warmer air.

Antarctica is melting and thus contributing to the total sea level rise - http://www.skepticalscience.com/antarctica-gaining-ice-intermediate.htm

No. The *sea ice* around Antarctica, which changes seasonally, has been showing a build-up for a variety of reasons, but the land ice mass, which is what's really important in terms of sea levels, has been decreasing. See here: http://www.skepticalscience.com/antarctica-gaining-ice.htm

Here's a pros-and-cons list (more overwhelmingly negative than I expected):

http://www.skepticalscience.com/global-warming-positives-negatives-intermediate.htm

Even assuming there were net gains to be had in the planet's carrying capacity or areas with "nice" climates, the big nasty problem that ruins it is ocean acidification.

Actually, there have been studies using objective criteria of expertise, such as number of peer-reviewed publications in the field of climate science.

But of course, the true conspiracy theorist will just insist that is because pro-AGW scientists are conspiring to prevent those who disagree from getting published.

Hi Namarrgon, Skeptical Science now has an Arctic Ice Escalator graph too.

There's no way the planet got to where it was without a cooling mechanism.

Technically speaking, the major cooling mechanism is probably sequestration of carbon. So all the oil, natural gas, and coal we've been burning may represent the results of three most important cooling mechanisms. Given that we're approaching the halfway point of undoing a billion years of work by those cooling mechanisms, I wouldn't be too optimistic about how quickly that cooling can be repeated.

More cloud cover is likely one. More heat means more evaporation means more clouds.

Net cloud feedback is likely to be weakly positive, meaning additional clouds will probably accelerate warming.

The ice caps don't cool the planet, they help keep the temperature stable.

Actually, white ice reflects more energy than water or land (that are darker). The effect is called albedo.

Again, don't get me wrong, I do my best to minimise my own impact on the environment, but is man's impact really large enough to melt all the arctic ice?

Yes, it is.

We're releasing about 30 Gigatonnes of carbon dioxide per year. It's small compared to the natural cycle, with is around 750 Gigatonnes, but we put more into the system every year. Any person who can do multiplication should be able to see that at the current rate it only takes about 25 years of emissions to equal all of the Carbon already in the cycle.

It's like leaving a hose running into a swimming pool, the hose is tiny and the pool is big, but even a small hose running constantly will eventually fill the pool up and then cause it to overflow.

You don't have to take a position of faith because there is ample scientific evidence showing that humans are causing the global warming of modern times:

http://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html

http://www.skepticalscience.com/empirical-evidence-for-global-warming.htm

If you are an honest skeptic, look at the full body of scientific evidence. Don't cherry-pick. Be open to all the evidence.http://www.skepticalscience.com/ is a good place to start.

You don't have to take a position of faith because there is ample scientific evidence showing that humans are causing the global warming of modern times:

http://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html

http://www.skepticalscience.com/empirical-evidence-for-global-warming.htm

If you are an honest skeptic, look at the full body of scientific evidence. Don't cherry-pick. Be open to all the evidence.http://www.skepticalscience.com/ is a good place to start.

You don't have to take a position of faith because there is ample scientific evidence showing that humans are causing the global warming of modern times:

http://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html

http://www.skepticalscience.com/empirical-evidence-for-global-warming.htm

If you are an honest skeptic, look at the full body of scientific evidence. Don't cherry-pick. Be open to all the evidence.http://www.skepticalscience.com/ is a good place to start.

How much of it would have happened anyway?

If we are talking since 1900, none of it according to the best models, if anything the globe would have very slightly cooled. The official IPCC position is more conservative and simply states that "most" of the observed warming is due to our activity (it's the second point in the much maligned 3 point scientific consensus)

rant/
A good place to start looking for more detailed answers on sun cycles and volcanos is here, and the youtube channel "climate crock of the week" is also a good place to visit for quality investigative journalism on the subject, (warning it includes strong British sarcasm). But for god's sake don't take my word for it, trusting a single source in the minefield of disinformation on climate science is quite likely to be fatal to your understanding of the issue. WP (or any other reputable encyclopedia) is also a good place to start, and it's hard to go past realclimate.org, it's run by Michael Mann (the hockey stick guy) and features articles and commentary by some of the world's leading climatologists. sourcewatch.org also has an extensive database of front groups, shills and lobbyists who publish climate misinformation, making it relatively simple for a genuine skeptic to work out who is bullshitting them and why. Make no mistake, if your interested in truth these "lobbyists" are your enemy, they will attempt to recruit you into the dwindling ranks of their army of useful idiots they have extensive propoganda experience that has been refined since the days the same people were paid to disrcedit medical science that said smoking causes cancer, somewhat surprisingly such expertise is cheap, (as well as fucking nasty).
/rant

Disclaimer: Unlike the so called "climate change skeptics" I want you to be skeptical of what I say and who I recommend. I've been following the science as an interested layman now for 30yrs, I want you to constructively attack the evidence I'm leaning on because (as a grandfather of three) the issue is way too important to allow the mediocrity you speak of in your sig to waste time and sow doubt amongst the uninformed.

A final bit of good faith advice (Aussie style) - Do you fucking homework mate, your ignorance.is your enemy's most effective weapon.

Right, just ignore the obvious downward trend for the previous 30 years on the graph; go ahead and cherry-pick your data so you can declare a 5 year upward trend! It's all so much simpler when you sweep things under the Seasonal Variability rug, isn't it?

Ever heard of the "Escalator Graph"? Yes, that's what you just did.

(Ed. note: I've been trying to post comments like this one since 2012-09-01, but they never appeared on my article at the San Gabriel Valley Tribune. So I finally posted this reply at my website, Slashdot, and Mike Haseler's website Scottish Skeptic.)

Let's get the facts straight. Even doubling CO2, means its greenhouse effect would only rise global temperatures by 1C. That is half the threshold for action set by the IPCC.

But, this scam has nothing to do with their real science. These charlatans would be predicting the same nonsense if CO2's effect were twice as high or half as much, because the real contribution of CO2 is much smaller than the natural variation.

And let's not forget:

1. This scam is based on a rise in temperature from 1970 to 2000 which happens to be coincident with rising CO2. The overwhelming bulk of this rise has nothing to do with CO2 greenhouse effect.

2. Largely the same academics who cry wolf over this short term trend were crying wolf over the short term cooling before the 1970s.

3. It all stopped in 2000 (1998 to be precise). That's 14 years without warming, compared to the 30 year trend they say proves warming will continue till the earth fries (much like we were heading for an iceage)

4. And just to cap it all, it warmed the same amount, for the same period, before CO2 was measured rising between 1910 and 1940 and guess what ... we didn't end up global warming doomsday then either. [Mike Haseler, 2012-09-01]

0. Many diverse lines of evidence (paleoclimate, modern observations, fundamental physics) show that doubling CO2 warms the planet by roughly 3C.

1. Human CO2 forcing has increased dramatically since 1970, while solar irradiance, volcanic activity, cosmic rays, solar flares, etc. have remained about the same.

2. Even during the 1970s, most scientific papers were predicting warming.

3. Skeptical Science's "going down the up escalator" shows at a glance that this often-repeated myth about global warming ending in 1998 is wrong.

4. The rate of warming from 1910 to 1940 was about 0.13C/decade compared to about 0.18C/decade from 1975 to 2005. But scientists don't simply compare the rates; they examine natural and human radiative forcings which change the global climate's total energy, which is indeed an average over at least several decades. In the early 20th century there was a lull in volcanic eruptions which usually cool the climate by blocking out the sun over a few years. Early human CO2 emissions and a slight increase in the Sun's brightness also played small roles. Internal variability modes, which shift energy from one part of the globe to another (i.e. climate cycles) are also important. Temperatures measured in the 1940s were warmer than the models; this discrepency is thought to be due in part to Ar

(Ed. note: I've been trying to post comments like this one since 2012-09-01, but they never appeared on my article at the San Gabriel Valley Tribune. So I finally posted this reply at my website, Slashdot, and Mike Haseler's website Scottish Skeptic.)

Let's get the facts straight. Even doubling CO2, means its greenhouse effect would only rise global temperatures by 1C. That is half the threshold for action set by the IPCC.

But, this scam has nothing to do with their real science. These charlatans would be predicting the same nonsense if CO2's effect were twice as high or half as much, because the real contribution of CO2 is much smaller than the natural variation.

And let's not forget:

1. This scam is based on a rise in temperature from 1970 to 2000 which happens to be coincident with rising CO2. The overwhelming bulk of this rise has nothing to do with CO2 greenhouse effect.

2. Largely the same academics who cry wolf over this short term trend were crying wolf over the short term cooling before the 1970s.

3. It all stopped in 2000 (1998 to be precise). That's 14 years without warming, compared to the 30 year trend they say proves warming will continue till the earth fries (much like we were heading for an iceage)

4. And just to cap it all, it warmed the same amount, for the same period, before CO2 was measured rising between 1910 and 1940 and guess what ... we didn't end up global warming doomsday then either. [Mike Haseler, 2012-09-01]

0. Many diverse lines of evidence (paleoclimate, modern observations, fundamental physics) show that doubling CO2 warms the planet by roughly 3C.

1. Human CO2 forcing has increased dramatically since 1970, while solar irradiance, volcanic activity, cosmic rays, solar flares, etc. have remained about the same.

2. Even during the 1970s, most scientific papers were predicting warming.

3. Skeptical Science's "going down the up escalator" shows at a glance that this often-repeated myth about global warming ending in 1998 is wrong.

4. The rate of warming from 1910 to 1940 was about 0.13C/decade compared to about 0.18C/decade from 1975 to 2005. But scientists don't simply compare the rates; they examine natural and human radiative forcings which change the global climate's total energy, which is indeed an average over at least several decades. In the early 20th century there was a lull in volcanic eruptions which usually cool the climate by blocking out the sun over a few years. Early human CO2 emissions and a slight increase in the Sun's brightness also played small roles. Internal variability modes, which shift energy from one part of the globe to another (i.e. climate cycles) are also important. Temperatures measured in the 1940s were warmer than the models; this discrepency is thought to be due in part to Ar

(Ed. note: I've been trying to post comments like this one since 2012-09-01, but they never appeared on my article at the San Gabriel Valley Tribune. So I finally posted this reply at my website, Slashdot, and Mike Haseler's website Scottish Skeptic.)

Let's get the facts straight. Even doubling CO2, means its greenhouse effect would only rise global temperatures by 1C. That is half the threshold for action set by the IPCC.

But, this scam has nothing to do with their real science. These charlatans would be predicting the same nonsense if CO2's effect were twice as high or half as much, because the real contribution of CO2 is much smaller than the natural variation.

And let's not forget:

1. This scam is based on a rise in temperature from 1970 to 2000 which happens to be coincident with rising CO2. The overwhelming bulk of this rise has nothing to do with CO2 greenhouse effect.

2. Largely the same academics who cry wolf over this short term trend were crying wolf over the short term cooling before the 1970s.

3. It all stopped in 2000 (1998 to be precise). That's 14 years without warming, compared to the 30 year trend they say proves warming will continue till the earth fries (much like we were heading for an iceage)

4. And just to cap it all, it warmed the same amount, for the same period, before CO2 was measured rising between 1910 and 1940 and guess what ... we didn't end up global warming doomsday then either. [Mike Haseler, 2012-09-01]

0. Many diverse lines of evidence (paleoclimate, modern observations, fundamental physics) show that doubling CO2 warms the planet by roughly 3C.

1. Human CO2 forcing has increased dramatically since 1970, while solar irradiance, volcanic activity, cosmic rays, solar flares, etc. have remained about the same.

2. Even during the 1970s, most scientific papers were predicting warming.

3. Skeptical Science's "going down the up escalator" shows at a glance that this often-repeated myth about global warming ending in 1998 is wrong.

4. The rate of warming from 1910 to 1940 was about 0.13C/decade compared to about 0.18C/decade from 1975 to 2005. But scientists don't simply compare the rates; they examine natural and human radiative forcings which change the global climate's total energy, which is indeed an average over at least several decades. In the early 20th century there was a lull in volcanic eruptions which usually cool the climate by blocking out the sun over a few years. Early human CO2 emissions and a slight increase in the Sun's brightness also played small roles. Internal variability modes, which shift energy from one part of the globe to another (i.e. climate cycles) are also important. Temperatures measured in the 1940s were warmer than the models; this discrepency is thought to be due in part to Ar

1. Some deny just man-made warming, but many deny warming too - at the very least some of the observed warming. Your a) and b) are tired and wrong, and just more evidence for my 3.

2. Switching to a better-updated site is hardly a shattering life change. You may have become knowledgeable, but you're unlikely to become much more of it if you hang around here.

3. On the contrary, I'm confident most people deny - and accept climate change for cultural reasons, just like their attitudes to everything from abortion to foreign policy. Few people, even very smart people, adopt a well-reasoned position on everything. They adopt positions consciously on a few issues they care about, and adopt the rest from the kind of people who seem to agree on those issues.

1. Some deny just man-made warming, but many deny warming too - at the very least some of the observed warming. Your a) and b) are tired and wrong, and just more evidence for my 3.

2. Switching to a better-updated site is hardly a shattering life change. You may have become knowledgeable, but you're unlikely to become much more of it if you hang around here.

3. On the contrary, I'm confident most people deny - and accept climate change for cultural reasons, just like their attitudes to everything from abortion to foreign policy. Few people, even very smart people, adopt a well-reasoned position on everything. They adopt positions consciously on a few issues they care about, and adopt the rest from the kind of people who seem to agree on those issues.

Actually the true statement IS that "this has never happened before". Ok, maybe it did happen in the interglacial periods before the last ice age, but not in the last 1450 years for which we have ice cores and other proxy data... and by that point there is no reason to not assume it to be true for the rest of our current interglacial unless you have some good argument to the contrary. You don't NEED the rather super-precise satellite observations we have for the last 33 years to make this kind of statement.

If this weren't so tragic it would be really funny seeing you deniers all flailing madly about for a way out of this one.

In particular, America and China.

China recognizes the necessity of action, and are developing huge wind farms. (6 at 20GW each. By comparison, France uses 80GW.)

A majority in the USA would like to see some action, and indeed, 1/5th of the USA lives under a carbon trading scheme -- with no evidence of any economic damage. A carbon neutral tax takes from the utility companies bottom line, and generates demand for energy efficient products and infrastructure. The official rggi report specifically shows that this is what has been happening over the last 10 years, with net savings for both consumers and business. Furthermore, this region of the US economy has grown in proportion to the rest of the USA. The "damage" of a carbon tax is a conservative myth. And besides, many Republicans want action on climate change, including supply-side economics guru Art Laffer.

Now, China wants the west to pay through the nose before it officially ties itself to any legally binding targets. Same with India, and the rest of the developed world. In my opinion, they have a victim complex, which does have some legitimate basis. But seriously: grow up.

But, returning to your post, it is too black-and-white to suggest that nothing is happening in the USA. And in China, the boots are marching.

Only the regressive climate-change denial machine stops real and cheap action on AGW, and for purely philosophical reasons that are not grounded in out best understanding of either science or economics. These people are not oil industry shills (although they do have oil-sugar-daddys) but they do really believe in the imminent threat of climate-change legislation.

History will not remember them kindly.