Wisbech you are dreaming of some kind of Utopia moving forward. If the world does reach 11 billion by 2100 and it is structured roughly the same as today then it will be a very different place.
Boil it down to your own home. IF for instance you live in a house with 3 other people, imagine the difference if there are 6 other people. Cramped right??
That will be the world with 11 billion. My view is that numbers will drop in the second half of this century when nature will intervene to significantly reduce the numbers of mankind who by then will have done enough to seriously upset nature in its capacity as current main tenant of this planet.
There are various possibilities of reduction one of which will almost certainly cull huge numbers of mankind. War, virus or just natural disaster or something else that none of us have even considered.
The world is heading for many changes in the not too distant future (say half a century) in my view.

"Many cultures wish to preserve their genetic heritage..."
You do not speak on behalf of British people. A majority don't mind and an equal number to yours actively encourage it. Even on your own side, most can't agree on what they think "Genetic heritage" is. Is it skin colour? Is it the good old "Love of the queen"? Is it "Britain and the commonwealth countries"? Before the Anglo-saxons got involved? Roman?
I strongly suspect that "Genetic heritage" is a dog-whistle but I'm going to assume it isn't. You need to give us a strong definition on what genetic heritage is, because as it stands, almost nobody in this country agrees with you and you are in danger of sharing a platform with some truly awful people...

...and if its down to skin colour, ironically you would really be in a minority

Maybe we're just quibbling over semantics. 'White supremacist' does certainly have connotations of superiority, but it is also used to apply to those who feel the 'white race' is facing an existential threat. Though the two groups overlap perhaps we just need a new word for the latter group, such as, 'white militant'.

From a scientific perspective, there really is no such thing as race. Genetically, a random Kenyan and a random Nigerian are likely to have more in common with an Irishman than they are with each other, such is the genetic diversity within Africa.

This reasoning is nothing but a blurring of reality.....it's the 'Zulus are Greeks' argument....of course all humans are similar...because they are human. However, it's ignoring the real distinctions between human groups for political purposes....in my view.

Race can be accurately and independently geographically attributed via genes even using everyday 'off the shelf genealogy packages.

If race didn't exist, sickle cell would be common place within all races at the same extents.

Edited by Stirlingsays (06 Aug 2019 9.44pm)

'Who are you and how did you get in here? I'm a locksmith. And, I'm a locksmith.' (Leslie Nielsen)

Was he claiming too?

You can't either.

I don't agree that a 'majority don't mind'. It's not something that a 'majority' have to deal with.

The majority have already kept their genetic heritage and when you look at the demographic map the majority of any race move to areas where their own race is in the highest numbers....that's the reality.

Every 'side' is a broad church. You could say this of any movement or group that come together on anything. No one is required to sign up to specifics.

You make plenty of assumptions and assertions here.....and I'm curious as to why you'd care.

No one is telling you how to behave or what to think are they?

You either agree or don't and you plainly don't so....fair enough.

'Who are you and how did you get in here? I'm a locksmith. And, I'm a locksmith.' (Leslie Nielsen)