My view is that the evidence for human-induced climate change is unequivocal and undeniable, but that there has been considerable fear, uncertainty and doubt generated by various interest groups, including corporations and right-wing political groups. Their aim is to make it 'politicized and complex' and to sow doubt about the facts, and they've been successful in so doing, unfortunately. — Wayfarer

That's cool, and probably true, but not the whole truth, as I think there has been considerable fear, uncertainty, and doubt generated by various left wing political groups and by blackmailing tactics in academia, the aim of which is indeed to make the issue politicized and complex. So I hope you'll forgive me for being a skeptic. That being said, I am opposed to pollution and hunting and in favor of conservation and environmental sustainability.

as I think there has been considerable fear, uncertainty, and doubt generated by various left wing political groups and by blackmailing tactics in academia, the aim of which is indeed to make the issue politicized and complex. So I hope you'll forgive me for being a skeptic. — Thorongil

Is that 'skepticism'?

The fact of the concentration of CO2 in the environment is empirical science. It's not the consequence of a left-wing conspiracy, and the suggestion that it is, is part of the attempt to discredit the science. There's been a lot of this misinformation put about, and it is having effects.

Is that 'skepticism'? — Wayfarer

Yes.

The fact of the concentration of CO2 in the environment is empirical science. It's not the consequence of a left-wing conspiracy. and the suggestion that it is, is part of the attempt to discredit the science. — Wayfarer

This is a clear bait, and I'm not taking it. I explained my views as thoroughly as I can and so will leave it at that.

It isn't the case that no solutions can be suggested; suggestions have been made. There are two problems with the suggestions: The tolerable suggestions do not result in enough of a reduction in CO2 and other greenhouse gases such as methane or CFCs to help a lot. The intolerable suggests could (probably) result in large enough reductions in green house gases to limit warming, but would also be extremely, and intensely, disruptive to most aspects of life.

Were we to abruptly stop processing petroleum, stop burning coal, switch to a 95% vegetarian diet, sharply reduce manufacturing, begin massive reforestation projects, reduce total world population, and so on we might bring global warming to a halt -- not instantly, but in a century or so. Some side effects of this approach would probably include: Economic collapse; massive social upheavals including revolutions; extreme dislocations of population; increased deaths due to exposure to heat and cold (not in the same places at the same time); a loss of health care infrastructure; and so on, and on.

"Severe disruptions" should not suggest inconvenience; it should suggest hell on wheels.

If we were to take the extreme measures and stretch them out over a century of time, then we would probably not achieve a stabilization or reduction in global warming. The consequences of not controlling global warming include: rising sea levels and flooding; the loss of trillions of dollars worth of infrastructure; more severe and more erratic weather; major environmental changes making food production much more difficult; increased insect disease vectors would result in several tropical diseases becoming much more wide spread (like malaria). Food production (meat or vegetable) would decline as a result of heat, resulting in widespread starvation. There would be massive migration and severe social conflict.

So, either way we're screwed.

Here's where I am a bit more skeptical, not because I wish to deny the claim, but because I don't know enough about it to have formed a definite position. Climate science, like most other forms of science, is in fact rather complex. I certainly think humans have had an impact on the climate (how could they not?), but as for whether our burning of fossil fuels is "largely" responsible for global and regional climate change, I don't know. Most scientists say that this is the primary cause. But some of these scientists' research is paid for by ideologically driven interest groups, which is somewhat suspicious (though does not in itself invalidate said research). — Thorongil

Not only do most scientists who have a relevant expertise in climate science, or atmospheric physics, believe that the enhanced greenhouse effect if largely responsible for recent global warming, the consensus is that this human contribution is somewhere around 110% of the observed temperature increase (from the latest IPCC assessment). It is thus more likely than not that the natural contribution was a mitigating, albeit short term, cooling effect. This is mainly due to the solar irradiance having dropped slightly since 1960.

Over the long term, the current natural tendency also is a cooling effect due to the Milankovitch cycles. Those cycles have been responsible for the recent glacial/interglacial transitions and for the slow cooling that occurred since the Holocene Climatic Optimum 6,000 years ago. Over the last 150 years there occurred a sudden reversal of this long term cooling trend and an accelerated pace of warming that tracks total atmospheric CO2 concentration (which is now higher that it has been in the last several million years and still increasing rapidly). The way global temperature is thus tracking CO2 concentration is in very good agreement with climate models.

Scientists are also discouraged from research that might be critical of the consensus view, a profoundly anti-scientific practice, given that all major scientific breakthroughs and revolutions in the past have occurred due to some individual or individuals challenging the consensus view. That, too, is somewhat distressing.

Not all scientific progress is progress of the revolutionary sort. There is also progress of the "puzzle solving" sort that happens during what Kuhn called episodes of normal science. Contemporary climate science is indeed "normal science". Scientists tend to be critical of individuals who seek to overthrow the consensus wholesale and promote a scientific revolution. This is not distressing. Before a scientific revolution has occurred, the proponents of the revolution often are seen by the mainstream scientists as fools or crackpots, and indeed this negative judgement is correct most of the time.

There is a very small minority of scientists who have a relevant expertise in climate science, who aren't crackpots, and who purport to be highly critical of the consensus. I am thinking of Richard Lindzen, Roy Spencer, John Christy, Judith Curry, S. Fred Singer, and a handful others. It is hard to see them as promoting a new revolutionary paradigm, though, since their arguments are very weak and all over the place. They all agree much more with the basic science endorsed by mainstream climate science than they do with each other; and their advocacy efforts mainly center on attempts to sow doubts throug highlighting cherry picked results. They do agree with each other on the ideology, though, since they all seem to be ultra-libertarians who believe government regulations and taxes to constitute the highest form of evil the world has ever seen.

So, either way we're screwed. — Bitter Crank

We probably are screwed to some extent but that is no argument for inaction. It might be extremely difficult, at this stage, to limit global warming below 2°C (above preindustrial value) by 2100. But we still have a choice between aiming at stabilisation not too much above this value after 2100, on the one hand, or exceeding 3°C or 4°C by 2100, with temperatures still increasing rapidly, on the other hand. Either way, the Greenland ice sheet will probably melt over the next few centuries, but the fate of the much larger Antarctic ice sheet is up to us. And so is the amount of ocean acidification, which is also a significant threat to fisheries.

Your "either way we're screwed" philosophy assumes that we must chose between the yellow and red lines. But our choice really is between the blue and green lines, since this is what is consistent with foreseeable scientific progress in renewable energy production and reasonable political will.

It isn't the case that no solutions can be suggested; suggestions have been made. There are two problems with the suggestions: The tolerable suggestions do not result in enough of a reduction in CO2 and other greenhouse gases such as methane or CFCs to help a lot. The intolerable suggests could (probably) result in large enough reductions in green house gases to limit warming, but would also be extremely, and intensely, disruptive to most aspects of life.

Were we to abruptly stop processing petroleum, stop burning coal, switch to a 95% vegetarian diet, sharply reduce manufacturing, begin massive reforestation projects, reduce total world population, and so on we might bring global warming to a halt -- not instantly, but in a century or so. Some side effects of this approach would probably include: Economic collapse; massive social upheavals including revolutions; extreme dislocations of population; increased deaths due to exposure to heat and cold (not in the same places at the same time); a loss of health care infrastructure; and so on, and on.

"Severe disruptions" should not suggest inconvenience; it should suggest hell on wheels. — Bitter Crank

Indeed. But still a smaller hell than the current path. A preemptive bubble burst might wipe out over half the population, an intolerable situation. But doing only tolerable measures will be far worse. It is the trolley problem. Do nothing and the calamity is 5x worse and history wonders why nobody acted. Do something and the weight of the consequences rests on those that altered the path and history remembers them. Heroes or Hitlers?. Probably depends if those that choose go down with their own ship.

I'm on board for big changes. I want to see a livable world for future generations, and not just far future generations.

"Screwed either way" because the rank and file of the world's population won't be making the decision. Almost certainly those who will decide will have the most to lose -- the ones who own the carbon producing infrastructure (which is huge).

I am heartened that city, county, and state level governments in the US, at least, (Europe seems to be better coordinated and China has a command economy apparatus) are moving forward on wind and solar energy while the Feds are burying their heads in a coal pile. Other countries -- in Africa, for instance -- are also using wind to good effect. Carbon salvation isn't just around the corner, but there is hope.

Adam Ruins Everything - Climate Change
http://www.trutv.com/shows/adam-ruins-everything/videos/climate-change-is-already-happening-now-what.html

I think the most convincing data is the long term data from ice cores, correlating temperature, CO2 levels and other measures over geological time. Of course some people have a problem with getting temperature from ice cores (the science is pretty sound however).

It is pretty clear temperatures and CO2 levels correlate well over the long term. It is also clear we have had a dramatic and sudden rise in the atmospheric CO2. Are we past the point of no return, in some ways yes but failure to take action will only exacerbate the problem. They are many other reasons to try decrease dependency on carbon fuels.

The glaciers and polar caps are melting, the sea level is rising, the corals are dying, the permafrost is thawing and releasing trapped CO2 and methane (a more powerful greenhouse gas), severe storms and weather events are increasing. You will never convince everybody (there are always skeptics and conspiracy theorists) but we can't wait for them.

I myself am not opposed to taking action on what are recognized by all to be things deleterious to the natural environment. I am opposed to the idea that the government is the best institution to carry out this action.