One should work against global warming and avoid extinction from it, even if it is non-anthropogenic

You're right, that if it were shown that there can be no goal-directed action (toward slowing/revering global warming {GW}) that is likely to succeed, then my syllogism would fail. I think you must have noticed that I didn't propose a single action yet - and that's why you opted instead to try to argue that there can be NO action that would be effective. It might have been better to wait until I did propose something, because to say that there is nothing at all that could possibly work is a very difficult statement for you to defend. The references are little help in this regard by the way. To the audience: Don't be mislead by the title of Singer and Avery's book that he quoted - they have no evidence that global warming is unstoppable and you'll be able to see that in the quote itself. There is a BIG difference between saying that a moderate GW has happened every 1500 years in years past, and that the severe-to-catastrophic one we are facing present-day is unstoppable. As my opponent stated himself, the only helpful and pertinent quotes would include information on whether or not extinction from global warming is stoppable - not whether or not it is man made or whether natural ones have happened in the past. The design of this debate was meant to avoid this part of issue altogether by assuming that it IS NOT man made, remember? Just because it may be natural, doesn't mean it is not stoppable. There are a lot of natural things that we humans have stopped - like the dodo bird for instance - dead in its tracks. I think it should be pointed out that the first quote is even counterproductive for my opponent. It says that 1.) GW occurs on a 1,500 year cycle, 2.) that it is moderate (not catastrophic like the debate requires us to assume) and furthermore, 3.) that we are only about 150 years into the latest cycle. The audience will probably notice that, given these facts, that just about a million important things have happened between the current and previous cycle. And these authors somehow want us to believe that this cycle will still be just as mild and unavoidable as the last - that happened before Christopher Columbus' time for goodness sake? I wonder if they realize that we are practically capable of building a floating sunshield around the globe? Watch the video on this page: http://edition.cnn.com... By the way, the industrial revolution has also happened between the current and previous cycle. This is the reason why many scientists suspect that the current cycle, which is the first ever true "tester" of the additional greenhouse gases, will be much worse. So you can see that out of the two assumptions built into my title at the outset, the one about eventual extinction is not even the unlikely assumption if nothing is done. And to the fellows in the comments section who suggested that my topic design was too constrictive, I would suggest that actually it was too gratuitous to my opponent: Because the only unlikely assumption is the one that he is himself enamored with, namely, that GW is not man made (is natural). So what we have is a seemingly difficult situation for me. We have a "natural" global warming that is not at all the GW that Singer is talking about - It's worse. Its harder to address, as I must advocate for, because it is more severe. It is the one most of us heard about that melts icecaps and puts New York city under water in the all too near future. My solutions (note: I am not a climatologist) 1. So I suggest, (to finally get a positive proposition out there), that we build this solar powered sun shield (see above source) around the entire globe. We could then use the massive amount of electricity generated to climate control and illuminate the globe underneath. 2. All the solutions that we have all heard about that actual climatologists and other scientists/engineers have proposed. Yeah, let's do those. 3. And let me propose another one - only as an example obviously - to show that simply asserting that there are NO possible effective solutions that one can cook up is a silly assertion. We can kill off every animal on the planet besides humans. This would increase the proportion of carbon-fixing vs carbon-liberating biomass (autotrophs vs heterotrophs) and drive down CO2 and methane gas in ways that weren't even possible in the last cycle. I bring up this last one as a hypothetical obviously - to show also, what it is that I really wanted to talk about in the debate (as I think I said directly, albeit in the comments section). The question is, how far are you willing to go in order to live? How much are you willing to sacrifice, of yourself and/or of others, to live? We haven't even got to that yet, because I feel my opponent is misreading the topic and talking cross purposes. You'll notice that his next two arguments (or really, sources) are equally beside the point. The second one, which mentions that we are committed to another 1 degree Celsius, could very well be exactly true. In fact, I think it is. But that is not at all a problem for me. That degree of warming is not the catastrophe we're trying to avoid - and it would not kill many humans at all. The GW we are talking about is much worse, and what would happen in the inaction/indifference you are suggesting. In other words, it doesn't matter if we are committed to another 1deg of warming from previous mistakes - just apply the above solutions PLEASE. And I'll deal with the 1 deg, because it's not the catastrophe we're talking about (because it isn't one). The third one, which mentions that CO2 is only a minor contributor to the greenhouse effect, could also very well be exactly true. In fact, I think it is, as you could probably tell by my mention of methane earlier. Methane is perhaps the most significant contributor to the greenhouse effect, and the most significant source of it is from cow farts. That is why we should kill all cows as I said before (I hope people understand my style, and don't think I am being fatuous; I am serious about thinking logically here). http://en.wikipedia.org... So to quote a reference that wants us to believe that it won't be too intense (in fact, the scientists you quote think GW will be good for humanity; see above source), and will be unstoppable - all just because there may be a natural cycle - is off. The scientists opposing consensus on GW are the minority, but you can see that the largest group of them are those that believe it is a natural cycle. I do not hold this as my belief currently, but part of the reason I worded this debate in this way is because it is the most credible minority view that tempts me. But what do these scientific facts about a phenomenon have to do with human decisions? Lets not try to find reasons to be unthoughtful or inactive on this issue any more! Thank you for your attention.