A consequence of global warming would be loss of the ice habitats, increased success of pest species, tundra turning to wetlands, coniferous forests will expand where tundras previously existed, and there will be an expansion of habitat available to temperate species. Global warming, and the consequent temperature rise, is a real thing, no matter how hard Trump tries to deny it.
The arctic ecosystems will be hit the hardest, as the ice is going to melt. There are real consequences to global warming, and this list of consequences is more of a cause and effect thing. As the ice habitats are lost, tundras become wetlands, which gives coniferous forests a place to expand into. This, in turn, gives temperate species more places to go, as well as more places for pest species.