Philip Hulme of the Bio-Protection Research Centre, Lincoln University, New Zealand writes in the 3 Feb 2012 issue of Science:

Climate change is likely to devastate native species and biodiversity.

But ironically, invasive alien species — which are a threat to biodiversity, human health, and food crops — are not likely to have trouble keeping up with the fast changes from global warming.

This is because invasive species on both land and water spread 20 to 30 times faster than climate change, and the rates are even higher for plant and animal pathogens.  And it’s partly our doing from increasing human trade, transport, and travel.

so at the same time native creatures are under threat from climate change, they’ll also be assaulted by alien invasive pests, pathogens, and weeds that can disperse even faster.