> yes, if the temperature dropped back to where it was a few decades ago, and stayed there.

Well, it may very well head back that way yet. (There are even some hints that this process may have already started, but it's far too soon yet to really tell.) But it may not go all the way back down to prior levels, nor would I necessarily expect it to stay there even if it did.

Remember that temperatures where relatively high during the 1930s, dropped to a relative low point during the 1970s ("Global Cooling"), and have since headed back up again. And all of this occurred while we were coming out of the Little Ice Age, which has led to a general overall warming trend over the past 150 years or so. Before that temperatures were relatively warm, maybe even as warm if not warmer than now, at least according to some.

So natural warming/cooling cycles, even on relatively short timeframes, are very real; the question is how much influence man is having on them. But be they natural, anthropogenic, or somewhere in-between, such cycles can certainly potentially be quite inconvenient for us, and perhaps even dangerous. They can also potentially be quite beneficial.

> GCC idea are mostly or all conservatives ... God child-proofed the universe

I think you're painting folks with too broad a brush there. I, for example, am just about as far from religious as you can get, and on any given day politically I might swing liberal or conservative, depending on the issue at hand. (I'm a bit of a wildcard, in other words.) And when it comes to voting, a candidate's political affiliation is often the last thing I consider, although I've noted that in my younger days I tended to vote more Republican while these days I tend to vote more Democrat or even Independent. Sometimes it's been a matter of noting which party has been acting more "cray cray" at the time and then maybe actively voting for more folks from the other party!

> do you think that humans can cause significant harm to the environment that needs to be regulated by the government, and has this happened in the past?

Harm? Regulated? Happened in the past? Yes, of course, to all of those. But sometimes regulation tends to go too far if left unchecked, so it has to be reined in a bit. The EPA has done wonderful things in the past, and still has work to do, certainly. But, for example, lately they have become fixated on something called "PM 2.5" (fine particulate matter), and have been looking for ways to regulate it. Except that it turns out the highest exposure you generally get from this comes from places like your own kitchen. So what are they going to do, ban frying pans and such? Sounds ridiculous, I know, but left to their own devices they might very well head down a path like that.

And remember the Gold King Mine spill a few years back, where the EPA caused a massive release of pollution into the Animas River watershed? When I first read about that I thought "What bad luck! All of the planning that I'm sure the EPA put into that project, only to have it blow up in their faces like that." But then after I read the actual details of that accident and what led up to it, I was like "WTF? The EPA shouldn't have gone anywhere near that mine to begin with!"

> Also, what do you think of ocean acidification?

Funny you should mention that. Knowing that CO2 dissolved in water forms carbonic acid, this was actually one of the things I started being concerned about myself, well before it was even being mentioned generally. But now that I know more about the situation I'm not particularly concerned at all.

Why? Well for one the oceans are generally alkaline, so it would take an awful lot for them to become generally acidic, which is what the term "acidification" implies. For another, I don't know how much I trust claims that the ocean has already decreased by 0.1 pH over a period of 150 years or so, knowing that they had to depend on proxies and a lot of educated guesswork in order to make such a claim. Even assuming that it's true, the change hasn't exactly turned the oceans into a lifeless deserts, has it? Meanwhile things like overfishing and pollution and such seem to be taking a much greater toll.

And the oceans, being quite dynamic places, have waters which routinely already go through short-term, cyclical changes in pH, temperature, salinity, and so on - generally much greater changes and on a much shorter time scale than what you could blame on CO2 and climate change. But the living things in the ocean long ago adapted to those fast changes in various ways (which includes potentially moving along to places more to their liking), so I don't think that a slow and steady but relatively small change in overall pH is going to hurt them much.

I once saw a discussion by someone much more knowledgable about ocean chemistry than I am, and he pointed out that while dissolving CO2 in fresh water certainly yields considerable carbonic acid, in ocean water it's a different story. That there are plenty of other things already in ocean water that work against the formation of much of that carbonic acid to begin with, or at least work towards neutralizing much of it when it does form. (I don't know how much you know about chemistry, but IIRC the discussion revolved around a concept similar to buffering, although as I recall it was a bit more complicated than that.) So once again this "the sky is falling" ocean acidification argument just doesn't seem to hold much water.

There's a lot more that I could say here, including some anecdotes related to the papers and such which I've looked at concerning the situation, but I will stop for now.