Section 2.7 directly addresses Natural Forcing, including 2.7.1 Solar Variability, which is one topic you touched on earlier. The IPCC of course is investigating human factors, but in doing so, they have numerous times considered other factors in their attribution studies.
Both include human activity. My added emphasis above in the quote you referenced highlights their own definition of climate change and what influences they consider. You'll see they consider more than human influences.
They briefly summarize several known cosmic scientists works and their findings as low impact and unlikely. They failed to include Svensmark's findings in the chart, because it offers a completely valid and intriguing alternative viewpoint. They introduced that section not in consideration, but as dismissive. That is what I find aggravating about current scientists; they are so easy to dismiss everything outside of what they believe. Science has become this strange new religion where people do not accept criticism anymore. Whenever there is a consensus of individuals, they work to block those who might conflict with their research and grant money.
My favorite modern example is the shroud of Turin. Scientists went with the hypothesis that it had to have been a medieval fake. They carbon tested it and proved beyond reason of doubt, that it had been made in the 12th or 13th century. With that, many did not feel the need to explain all the irregularities with the shroud, nor how such a strange stereographic image could be made. They worked to PROVE why they were right, and did not want to consider that there are other possibilities.
Then comes along this couple, and they used the internet to come up with a hypothesis. Under different light spectrums, the edges of the cloth appeared in a different spectrum then the center where the image is. They hypothesized that the cloth was tattered and in the 12th or 13th century, special weaving was added to the fringe in a french technique to make it whole for display.
One of the scientists, an atheist, who had worked hard to prove that the cloth was a fake, got permission to take one of the samples and prove without a doubt that he and the rest of the community were correct. His findings were shocking, and also interestingly passed over by the media that had trumpeted the shroud as a fake. The couple was right, and he wrote a lengthy thesis about his findings that had shocked him.
I feel that it is the duty of our leaders, both corporate and government, to investigate all possibilities. This very narrow approach to a complex world wide system has been given so much money and time, while massive problems go overlooked. I am all for being more environmental responsible, but at the cost and scope they are talking about, is ridiculous. Conservation is responsible, fear mongering is not.