newspaper on its own will never be enough! :o
besides, once the temperatures drop, he will have nothing to cuddle into, hell be too cold!
Me personally, I use woodshavings (never sawdust!) and see nothing wrong with it. Yes people say they are bad for piggies breathing, or piggies on shavings are prone to fungal, but in all the time I have kept rabbits, and later guinea pigs, I never had any problem like that. I think woodshavings are great, very absorbant, they can go into the gardenwaste bin, very cheap, etc.. Other people will tell you differently.
However, if you do not want to go for woodshavings, there are plenty of other things you can put on top of the newspaper. Hay, for example, though I find its not that absorbing and the cage will need cleaning sooner than with other bedding.
You could use megazorb, if you got a supplier near you, vetbed fleece or towels if you dont mind using your washing machine for piggy stuff, some people use paper shreddings, there are loads of review threads for the different bedding types in this section of the forum, go have a look
But having a piggy solely on newspaper isnt a good idea in my opinion... nothing to cuddle into, to burrow into, nothing to keep you warm.. its like a guinea pig sleeping rough!