Er.....
Im now totally confused.
I now know how a greenhouse works and what greenhouse gasses are.
I also now know that we have been making CO2 since the 2nd world war.
The warming has been happening for 100 years or so and doesnt look like it matches with our burning of fossil fuels.
Its now the average temp its been for the last 3,000 years.
It might get warmer if the sun gives off more heat, or cooler if it doesnt,
Without greenhouse gasses - which include clouds, this place would be 33 degrees colder.
What have I missed or misunderstood?
Very roughly speaking what you have said there is correct. We could work on the statements a little to make them a little more accurate and in at least one case less misleading but I'm not sure that you've missed or misunderstood very much. The statements are not inconsistent but it seems that you don't like that figure of 33 degrees. Is that your main problem? If so, then I think that the reason you're having trouble with it is that global warming has been happening for all of those 3,000 years, and then some.
Nobody is saying that the greenhouse effect has only just started to happen. It's been happening more or less for as long as the planet has had an atmosphere. Without it, the planet wouldn't be the temperate place it is -- it would be a ball of ice -- and we wouldn't easily be able to live here.
Unfortunately however that 33 degrees is starting to creep up, by something in the region of 0.2 degrees per decade. That's mostly because we're pumping carbon dioxide into the atmosphere at an ever increasing rate. There is a lot more carbon dioxide in the atmosphere now than there was at the beginning of the industrial revolution (not just since the second world war). Before the 18th century, for almost a million years the CO2 concentration in the atmosphere was pretty stable at between 180 and 280 ppm. Then, because of the ever increasing population with its insatiable demands for comfort, travel, leisure, entertainment and trinkets the concentration started to rise. It's now almost 400ppm and it's still rising rapidly.
No matter what the head-in-the-sand crowd tells you, these measurements tell the truth. There is no escaping them. To deny that the greenhouse effect and global warming exist is like saying that standing on the beach and saying that the tide won't come in. If it weren't so tragic it would be laughable.
I do wish that this were not true. If it were not true, I wouldn't have to be careful with the heating. I would enjoy my motorcycles so much more. I would travel so much more. I would consume so much more. But I don't. Not because I can't afford it -- I'm very fortunate and I can easily afford it -- but because I know the planet can't afford it.
There are many people who deny the facts. At least one of them says you can't possibly know that these facts are true because you haven't made the measurements yourself. My reply is how can you know how far it is to the South pole when you don't have a tape measure long enough to reach it?
Most of the 'deniers' are just clutching at straws as they gradually sink into the depths. Their arguments are painfully transparent attempts to bolster their unwillingness to accept the reality which we all have to face.