No, the headline says they are scared of climate change (which is not a "someone", but a collection of serious consequences) and then includes the irony that they are contributing to that very threat as a big polluter.
You may have seen the updated headline, which is much clearer.
Very possible - I didn't realize it had been changed. My apologies.
I read it the same way: The military is scared of climate change and of the world’s biggest polluter.
OP here -- I can see how that could be read incorrectly. Updated for clarity