Yes. I truly do. Lots of people say it is the orbital tilt and has a lot to do with the earth's warming and cooling periods but if this was the case things would be different. We have melting permafrost which is worst that CO2 because it holds 20x as much heat. We have hurricanes gaining strength and reaching further into land. Evidence for this is by looking at the major hurricane so for starting with Katrina. Then Irene. Then Sandy. Weather around the world is changing and temperature are fluctuating more than usual. The ocean temperature increased by 1 degree. People usually say oh it's just 1 degree that is nothing. But you must realize that 1 degree could kill life in the ocean. Plankton are migrating upward making whales travel further for there food and we have been seeing whales that are skinny and have their spines sticking out. They are malnourished. We are seeing species that usually remain near the equator migrating upward because the water has warmed. The ice is melting on the caps and this is critical because white ice reflects the most light and with less white ice the ocean absorbs the heat. Australia is going through intense desertification. Ozone used to be a problem but the Montreal protocol has handled that because that was about CFC's. Now it is about carbon and other gases making our atmosphere thicker which keeps heat inside of our atmosphere. CO2 is the most well known one but there are other pollutants such as mercury or even sulfur. Methane is a big one as well. We are seeing plants beginning to adapt to the increasing heat levels and phytoplankton are slowly dying out. Global Warming is a major problem.

Do I believe it exists? Yes, because the scientists say so, and show evidence of temperature increases. Even in the summer I feel hotter than I usually do, but I am a simple person with a body that's ever changing so my 'feelings' are not enough to go on.

Do I believe it was caused, or mostly caused, by humanity? No, because there are so many factors involved in the temperature of our planet, that's considered technically perfect for life to exist, and the planet is so vast. It's small compared to the solar system that may be able to affect it's temperature, but it's large to people who only inhabit a very small portion of it. I read somewhere once that all the people in the world could fit shoulder to shoulder in California or something similar to that.

....if I believe that heat melts ice? Yes, I do .

I live in Scandinavia.

When I was a kid I remember thick snow in the winter, like real snow you can go out and play in, and I remember having beautiful springs and lovely summers.

Now we have only one season and that is fall all year long.

It is too hot for the rain to become snow, but it is too cold for the rain to be pure liquid, so it's like a disgusting combination of rain and snow and it sucks.

I hate global warming.

Of course yeah. We can see the increasing of water volume of the sea every year. Earth is going to its next age time.

It is now 2015 and even Pope Francis has written an encyclical warning about global warming.