The gist seems to be that he read about an omission in climate models, claims it's grounds to question the evidence for climate change, and takes umbrage that others disagree. In particular, he quotes:
The atmospheric chemists from France and Germany, however, could now show that isoprene could also be formed without biological sources in surface film of the oceans by sunlight and so explain the large discrepancy between field measurements and models. The new identified photochemical reaction is therefore important to improve the climate models.
From this he concludes:
The computer models on which anthropogenic global warming theory are based are inadequate to the task because they fail to take into account all the real-world data.
Earlier in the article he stated:
You don't need to be a climate scientist to understand this stuff. Or even a scientist.
I don't find the article convincing, because I think you do need an understanding of a model to determine how much of an impact a discrepancy in particular data will be likely to have on the model's reliability.
In some particular model, some data may be critical, and other data less so, and it may be possible to approximate some data without a large effect on the outcome. To take an extreme example, astronomical models often approximate stars and planets as point masses, thereby approximating all of us out of existence. This is clearly a gross approximation for many purposes, but often not so much of an issue for astronomy.
I know something about astronomical models, at least with regards to Newtonian physics, and am fairly comfortable making the above claim. I don't know much about climate models, and don't claim to know the significance of the discrepancy. There's nothing in the article, however, to convince me that the author knows any more about this than I do.