The blogger says that the average IQ in Europe and North America is 100 but that "the mean IQ of the world is a tad less than 90 today, and it's expected to fall to about 86 by 2050." So the blogger thinks that some races are much stupider than Europeans, and that if their share of the global population rises, average intelligence will fall. That sure sounds like he thinks this is a genetic difference and not poverty, disease, or lack of education.

The blogger cites a website which cites Richard Lynn for these 'facts'. So this is about race and IQ, quod erat demonstratum.

Differences in average IQ between countries is well established and not even controversial AFAIK. What they mean is debated. Their existence cannot really be debated at all.

IIRC it correlates very strongly with socioeconomic factors, at least within the US. That doesn't make it useless but it does raise an awful lot of questions.

The direction of causation between IQ and economic success is pretty difficult because they obviously drive each other.

> So the blogger thinks that some races ...

You are misrepresenting the author. He made no such claim. He did not articulate what he believes the underlying mechanism to be.

It would be perfectly reasonable to inquire about the mechanism, or question the accuracy of the prediction. It is not reasonable to make accusatory conjectures about his beliefs.

The blogger is repeating (with citation) a claim by Richard Lynn, and by the end of his life Richard Lynn was open about being a 'scientific' racist who believed that different races had genes which caused large differences in average intelligence