OK, and this is part of climate change how? They have done it for years, but now it's part of "climate change"?
Right. We do the anti-science thing in slashdot these days dont we. *sigh*
Penguin observations are something I'm fairly closely involved with professionally. That climate change affects penguins isn't controversial amongst researchers, its something we've known for a long time and studies on it go back to the 50s at least. Basically , penguins don't use magic to navigate, but rather fairly detailed memory of environmental conditions and landmarks. "Hey this is where the water turns cold with the shore to my right. I better start swimming south where there are more tasty fish" kind of thing. The problem is, these forms of navigation are super succeptible to environmental change, and whilst climate effects of CO2 are only starting to become widely felt, the effects on the ocean so far have been huge, particularly near the poles Again , none of this is controversial, we know this to be true.
Now I'm not much of an expert on Emperor penguins (The project I'm working with does obersvations of fairy penguins whos range isn't as far south as the emporers who are strictly ice dudes) but my understanding is they have never been observed to change nesting location so the question is *why*. Well Antarctic is interesting in that it doesn't change an awful lot, theres not a LOT of variables at play here , but one BIG change is that warmer currents coming in caused by climate change (Some marine biologists joke that climate change should be could 'sea change' because it tends to dispropirtionately affect oceans, and a 'sea change' might be your career path if you do climate science and the fundamentalist right regains power and starts defunding evolutionary biologists and climate physics again).
So its a guess that its the cause, but its a good guess because it seems the most likely candidate, all things considered.