So, there's a lot of things wrong with this, including some Bad Anthropology and Social Science, but I'm going to stick with the history. I'm pulling the actual sources this article claims to reference as I go, so any corrections or additions are welcome. Here we go.
Ephorus (c. 405BC) claimed that the Celts were Blacks or Ethiopians
I'm not entirely sure why the article cites a secondary source rather than the source itself, when it's readily available on the internet. But, Ephorus makes a point to differentiate between Celts and Ethiopians.
The Indians inhabit the east and the country towards the rising sun; while the Ethiopians dwell towards the south; to the west the land is held by the Celts; and the north is peopled by the Scythians.
As we can see, Ephorus considered the Celts and the Ethiopians to be a separate people.
The Celts continued to be recognized as Blacks by Tacitus, who wrote about the Black Celts and Picts in 80 AD .
The source in the article is a book called *Sex and Race, v. 1" by J. A. Rodgers. Here we can see the cited passage. However, it cuts Tacitus short:
The dark complexion of the Silures, their usually curly hair, and the fact that Spain is the opposite shore to them, are an evidence that Iberians of a former date crossed over and occupied these parts.
Tacitus would have been familiar with both Iberians and some Sub-Saharan Africans. If they looked like Africans, he would have described them thusly. He did not. The article in question even makes the differentiation itself:
The Iberians were probably conquered by the Ligurians.
This tale comes from Thucydides, and he is pretty specific that the conquered people were Sicani. I suppose it's possible these people could have been black, but there is no evidence of it that I know of.
This is supported by the Ivory Lady of York ,England. The reconstruction of the face of the Ivory Bangle Lady (c.350AD) indicates that she was African or Black.
The most recent information (2010) about the Ivory Lady that I could find makes no mention of any possible sub-Saharan ethnicity. Mediterranean, Berber, Phoenician...
The original Danes or Vikings were Blacks .
No they weren't. There are plenty of medieval depictions of vikings, and they're quite pale. I haven't been able to find anything from the 8th-century specifically, but unless something pretty cataclysmic happened in a couple generations, the Danes were what we would think of as "white".
This is made clear in the Oseberg 8th Century Vikings on the Norway Sledge carving of the Black seafarers that populated the region at this time.
I'm really not sure how but, regardless, the sled aparrently dates to the late 9th century.
Personally, I think what we have here is some people inferring way too much based on passing historical mentions of various peoples being "black", when that phrasing wouldn't be used to describe sub-Saharan Africans until much, much later.
It's also worth noting that the sources are decades (if not over a century) old.
For those of you wishing to find more bad history, the comments are a gold mine.