It doesn't say that anywhere. All it says is that the observed climate change is "most likely" due to human activities.
We have shown that the biosphere is indeed changing, due to a climate change that most likely is a direct consequence of human activities (principally in the industrialized countries).
There is absolutely no evidence in the article as posted that the change is "most likely" a direct consequence of human activites in the industrialized countries. This is pure propaganda/unfounded speculation. There is no discussion of possible causes; just a remarkable leap to pin the blame on humans activity in "industrialized countries."
The biosphere is in a constant state of change and the possible causes are many and varied. The article ignores mountains of real evidence that biosphere change is caused by long-term natural processes unrelated to human activity. The work of these computer modelers cries for objective peer review as well.