Intriguing, more questions than answers.
He seems to be called variously Christopher Abel and Christian Abel (I don't think there are two of them )
There is an 1851 Masters cert issued on 9th May by the Port of London Authority under the name of Christopher Abel Warming (address 3 Philpott Street as on the census) . This states he was born in Dublin in 1800.
He is also down as Christopher on the 1839-43 electoral registers for the same address.
The name of one of his sons Henry Maximillian Thalwitzer though certainly doesn't sound English. I found that this son was registered in the Protestant Dissenters birth registry (DOB 19 May 1837) but was baptised in the Parish Church of St Dunstan Stepney in 1844. However there were children baptised earlier in the C of E .(the register gives maternal grandparents as David and Sarah Archer, but not paternal grand parents)
There are 2 documents at the National Archives (application for Edwin b 10th Dec 1829 and also for Henry Maximillian ) The description for the latter shows that Christian claims to have been born in London.
Henry Maximillian Thalirtyer Warming. When admitted to Greenwich Hospital School: 25 February 1848.
Parents' names: Christian Abel and Ann Warming.
Applicant born 19 May 1837 and died 11 December 1852 in Rangoon. Sibling: Edwin admitted to Upper School in 1841. Father born in London. Parents married at St Olive's. Southwark on 28 June 1824
Be interesting to see if anyone has some source for the Danish birth