One of the most common claims I hear people use to 'prove' AGW isn't real is that the climate changed in the past. Contrarians will cite climate cycles and prior changes and say, 'it is all just a natural cycle'. But, this is all a big false argument.
The argument contrarians make on this topic goes this way:
There were warming cycles in the past;
This is a warming cycle today;
The warming cycles in the past were naturally occurring cycles;
Therefore, today's warming cycle is naturally occurring.
Let's try it again and you can see how it is a false argument:
Pneumonia kills people;
Gunshot wounds kill people;
Pneumonia is a naturally occurring disease;
Therefore, gunshot wounds are a naturally occurring disease.
In both cases, the second does not follow from the first. The fact that there were warming cycles in the past does not, in any way, show that there is any connection between what is going on today and what went on in the past.
Well, there is a new paper with media coverage that I am sure will just stoke this fire all over. This paper discusses the general warming trend that has occurred over the last 10,000 years and some different results between different researchers. But, anyone bothering to actually read it will see that it doesn't dispute AGW. Read the paper and look at the graphs in the article. The differences between results are relatively minor and do not do anything to contradict man made global warming. They even state in the article,
Yet, the bio- and geo-thermometers used last year in a study in the journal Science suggest a period of global cooling beginning about 7,000 years ago.
It claimed that this continued until humans began to leave a mark - the so-called 'hockey stick' on the current climate model graph - which reflects a profound global warming trend.
I hope this precludes false claims about how this shows AGW isn't real, but I also know it is a false hope. The science is there, accept it or reject it, but the science will still be there.