And...
“A hypothesis can be refuted (proven wrong, or falsified), but it never can be proven to be true. (It is impossible to perform enough experiments to be certain that the answer will always be the same, and that the same explanation will hold true every time.) However, if a hypothesis is tested again and again and is never falsified, it may become elevated to the level of a theory.”
http://www.bio.miami.edu/dana/dox/scientific_method.html
The historical record shows that the climate system varies naturally over a wide range of time scales. In general, climate changes prior to the Industrial Revolution in the 1700s can be explained by natural causes, such as changes in solar energy, volcanic eruptions, and natural changes in greenhouse gas (GHG) concentrations.
[ NRC (2010). Advancing the Science of Climate Change . National Research Council. The National Academies Press, Washington, DC, USA.]
Recent climate changes, however, cannot be explained by natural causes alone. Research indicates that natural causes are very unlikely to explain most observed warming, especially warming since the mid-20th century. Rather, human activities can very likely explain most of that warming.
Do you see the words in bold? This means they do not have any proof. If there was definite evidence humans are causing climate change the "scientists" would use definitive words. Indications and likelihoods are not facts.
Does one say "It is likely the sky is blue."? No. We can see the sky is blue and use definite speech to declare it.
Does one say, "My studies indicate when I add 4 cups of sugar to a quart of water it will taste very sweet."?
No again, because we have clear evidence adding sugar to water makes the water sweet. We do not use "indicate" or "suggest" or "it is likely" when the facts are clear.
Do not be fooled by the global warming buffoons. I am certain there is a long term goal in mind, most certainly the result being a loss of freedom, a loss of constitutional rights such as: "You exhaled the pollutant carbon when you used that speech, so to avoid pollution you must not use that type of speech anymore."
I know that sounds utterly stupid but that is the kind of stupidity coming from the liberals these days.
Something stupid and hateful towards our freedom is on the way if we do not stop the AGW garbage soon, mark my words.