I'll start by saying yes, global waring is a theory, so is gravity. That is the strength of science is that everything can be challenged. But I you don't see people jumping off of buildings because they don't believe the science of gravity. Here's what we know; the earth is getting warmer faster and faster over time ever sense the start of the industrial revolution, CO2 is a “green house gas”, and the planet goes through natural cycles of hot and cold.
If you look at the history the earth it does go through cycles. These cycles are ultimately driven by the sun but can be varied due to planetary wobble and green house gasses. This chart shows what the natural trend of the planet should be (the dark orange line) and when humans started to settle we domesticated animals, cleared forest and developed agriculture. These events cause a build up of green house gasses and are denoted by the yellow shaded area. Then we started industrialization and temperature started to increase even more this is the orange shaded area. And if trends keep up we will be in the red shaded area. This area is the continuation of using fossil fuels and then running out. If we keep up on this trend we will abruptly run out of fuels to burn then we will plummet (with in 100 years) into an ice age. If you have more questions about the truth about global warming let me know. Also I will be doing a more in dept proof before the end of the year.
Ideally we would get off of fossil fuels just enough to keep us at a comfortable temperature. The only way to realistically do this is for government to mandate that we stop burning fuels in power plants. Lots of people don't like when the government tells people what to do but the way our economy is we will never stop using these fuels until they are gone. The reason we need a change on a higher scale is because even the effort of all the people in the would reducing there power intake would not stop the trend ultimately. We will always use more and more power as we learn more about physics and improve our lives.
We need to start from the top and work our way down because ultimately most of our power will come from the power plants. After we have clean power source then the rest of the transition will be easy. We don't have to use only renewable sources, nuclear is a very good option because the wast is solid and manageable. Our next biggest problem is the cars. We can't handle them first because all of the methods to make cars that don't use oil rely on power from a power plant. Battery's getting charged, air presser comes from an air pump, and even hydrogen would rely on electrolysis (passing electricity through water so separate it into hydrogen and oxygen).
Then after the planet stabilizes and we accessed how much green house gasses we need to stay at a comfortable level we need to start burning again. If we don't handle this properly we will experience climate whip lash with first abnormally high temperatures followed by an even faster decline. This will cause many animals to go extinct (not just the polar bears though they could be first) and plunge us suddenly into an ice age that we can't do anything about. If we manage our resources properly we can postpone the ice age lone enough to come up with a better solution.
