Well i've said that already. As you said, climate changes happened often in earth's history. My claim is, that none of these raised temperature like we experience today *within 200 years*.
https://de.wikipedia.org/wiki/Bild:Phanerozoic_Climate_Change.png
The time scale below is the important part (=> millions of years).
Also important: (from wikpedia, global warming)
That's why i ask *you* to give facts and reasons why you do not accept the "prevailing scientific opinion" and what expertise you have on that issue to claim that.
As I have already made quite clear, I do not profess to have the scientific expertise to support every detail of what I conclude - either in those aspect of the subject I do agree with you or in those where I don't, but, while keeping as open a mind as I can on the issue, what I will say in the interim is that I do not accept that anything is unequivocally the "prevailing scientific opinion" just becase it says so in Wikipedia. If all the world's bona fide, trustworthy and independently unbiased scientists agreed on this subject, that would be a rather different matter, Wikipedia or no Wikipedia - but it appears that there is no such global consensus within the scientific community.
In my opinion it is absolutely logical that such a big system like the earth's ecosystem can *not* change so much within such a short time. It's like between ants and humans: a second for a human is a much longer time for an ant (i know this is not very scientific, i hope you get my point).
Yes, I do get your point.
There are so many factors, sunlight, greenhouse gases, wind, water...without intervention from outside (asteroids etc) these are things that change slowly, and if they change (they actually change constantly) it also takes long until there are measurable effects. Edit: Additionally, the effects are also pretty small.
Whilst your argument about time-frames may well hold water to some extent, I cannot accept that "the effects are also pretty small"; look at the extent to which land mass and ocean patterns have changed over the millennia and you will surely not think such changes "small", any more than the climate changes either side of an ice age were "small".
You're right concerning energy. As i think about it, i realise that forcing the western world to reduce consumption takes even longer than doing the necessary research 
I still think reducing consumption is necessary because of social and personal reasons. I don't like that unnessecary and exaggerated consumption and i think it has negative effects on people. It is a way to distract people from important issues and problems.
...ok i know not good explained, you know...the language^^ i hope you get what i mean.
I do get what you mean but I do not accept that ambulance drivers should have to give up driving just because some inconsiderate SUV drivers have over-used their gas-guzzling cars. Now I know that this is a ridiculous scenario, but the point of it is that reduction in car use to "practical minimum levels" simply cannot be achieved because there are, as I said before, no norms against which such vehicale use can sensibly be measured the world over. As to other consumption, the problem is not in how much of any given thing is manufactured and consumed but in how all levels of consumptuion of all goods and servies can be policed with a view to creating some kind of maximum use. This is a political non-starter and would still be so even if there was just one world government, because corporate and personal circumstances in different parts of the world vary greatly, just as do the degrees of wealth and poverty in the various countries.
I'm talking about fresh water, not about the water that maybe one day will come over all Bangladesh...concerning fresh water, yes there are problems, lots of people do not have it because their region das not have fresh water any more...etc etc. I call this water shortage. It will become worse in the future. Some cities in Europe already forbade using too much water (for gardens especially) in some hot summers. What does that tell us?
I know exactly what you're talking about. What I'm talking about is that research and development needs to be undertaken to create and distribute clean water supplies for human use; there are indeed serious shortages of fresh water for human consumtion in various places, but my point was that there is no overall shortage of water on the planet (indeed, global warming warns us that there'll soon be much more of the stuff), so it's up to humanity to figure out how to put as much of it as possible to good use. Again, water metering is strongly advocated these days; what this means is that wealthier people will use ever increasingly higher proportions of the water made available by water supply corporations.
Yes, because oil is bad for the environment and as i said, imo mankind should get away from it.
Digging very deep also means high costs, after a certain depth it is not profitable anymore, there's also the issue with the heat in great depths.
Leaving the practical economics of oil exploration to those that are involved in it, I have already made my position clear on this subject; the fact that one of the world's largest motor manufacturers recently abandoned the completion of a project to bring us the first version of the EV1 - almost certainly likely to have been the fastest, most efficient and practical all-electrically-powered personal motor vehicle that would ever have reached commercial production stage - is surely as large an indictment as you'd want. We should be on the third or fourth generation of these kinds of thing by now - and, if we were, no one would any longer be able to bleat about reducing car use. The all-electric plane is still a long way off; it shouldn't be.
It's the greenhouse gases that do this. Yes, i do think mankind has managed to do this in just 200 years. remarkable, isn't it?

That just shows how much impact mankind has on earth. Consider there are 6 billion people on this planet, how many billion cars are there, how many factories, how many tons of CO2 over how many years?
And just how much less greenhouse gas production do you suppose there would be on earth if even 25% of all cars, homes, factories, etc. depended upon non-fossil fuels for their energy consumption? An awful lot, surely? Just how much and how rapidly such a scenario would reverse any climate change remains open to argument, but it is academic in any case, since the research and development required to bring about such a situation is in its comparative infancy and is being carried out only sporadically.
What about those 6 billion + people, all breathing out carbon dioxide 24/7, then?
Industrialization is fully responsible.
No - too much bad industrialisation and not enough good ditto may be partially responsible.
I also think that the formulation used in the quote from wikipedia above ("most of the warming observed over the last 50 years is attributable to human activities" [1].") is very deliberate since there are still many people out there who deny any human involvement at all
As you know, Ii am not one of the people who does this.
if you inform yourself carefully about the subject you come to the conclusion (at least i do, but others also) that this actually means 95% of the glolbal warming is caused by humans. I think thats scientifically justifiable.(=>statistics).
Leaving aside the old cliché that tells us that there are "lies, damned lies and statistics", there is not, as I have already observed, general agreement in the independent scientific community as to the extent either of climate change itself or of the extent to which human activity is responsible for it; that is not at all to say that human activity has played no part - merely to point out that the extent of that part has not been determined to anything remotely approaching the unanimous agreement of the scientific community. Again, however, just because this agreement has not been reached should not be an excuse not to try to undertake the appropriate R&D.
The sceptics deny everything of course, often these are the same people who are part of an industry that is rather ecologically harmful, earn their money with it etc.
Yes, well there will, of course, always be vested interests, as you say; this is indeed the very kind of thing that has kept the oil industry so buoyant at the expense of other fuel research for so many years.
To the question of how i think this is possible...with quantity. As i said, so many cars, so many factories, so many energy consumed, so many people.
So do you advocate the compulsory reduction of all of these categories? Population growth is indeed a problem if there are not the goods and services, food, energy, etc. to support enough people to live decent lives, but then we are not actually short of resources - we are short of the kind of work that can enable the right sort of resources to be used for the general benefit of humankind.
But what are governments doing about this? Telling us that we're going to have to pay more "green" taxes, that's what! And where will that money go? Well, we certainly do need more money to send more armed service personnel to Iraq, Afghanistan, Somalia, Iran (all oil producers, coincidentally!)...
Best,
Alistair