You know, it's good to actually read Wikipedia before linking it. From your link :
> The major competing hypothesis is the multiregional origin of modern humans, which envisions a wave of Homo sapiens migrating earlier from Africa and interbreeding with local Homo erectus populations in multiple regions of the globe. Most multiregionalists still view Africa as a major wellspring of human genetic diversity, but allow a much greater role for hybridization.[12][13]
And no need to put a Strawman about global warming in your answer.
Your own quote still maintains "Africa as a major wellspring of human genetic diversity".
The multiregional "hypothesis" merely puts the "out of Africa" hypothesis earlier in time, i.e. puts back the date at which modern humans migrated out of Africa, rather than disputing that central fact.
There is as yet no evidence for pre-modern humans anywhere but in Africa. Further, genetic evidence we have today does not support interbreeding of modern humans with Homo erectus outside of Africa, which would be necessary for the "multiregional" hypothesis to have any weight.
The exception to this would be if you were to classify Neanderthals or Denisovans as non-human.
Edit: There is now also evidence for a return migration of Europeans back into Africa:
> The major competing hypothesis is the multiregional origin of modern humans, which envisions a wave of Homo sapiens migrating earlier from Africa and interbreeding with local Homo erectus populations in multiple regions of the globe. Most multiregionalists still view Africa as a major wellspring of human genetic diversity, but allow a much greater role for hybridization.[12][13]
And no need to put a Strawman about global warming in your answer.