I'm no liberal, in fact I quite dislike them, but I'm already under the impression that their new leader will be much better.
Harper is morally repulsive. His party gets all its finances from big private companies, which can obviously donate a lot more than your average person. So what does he do when he sees this? He tries to cut all public support to the parties (his being the only one which doesn't rely on it) to have financial means 100 greater than the other 3 leading parties combined, making it for all practical ends a one-party system. When others protested this outrageous move, what did he do? He went to get that antiquity of a governor general to prorogue the government, essentially meaning that during a period where the government really ought to have been making good decisions to prepare Canada for the hard times to come, they were all on vacation and the issue was dismissed.
He also calls for elections every other year in a hope to get his majority to do all of his stupidity uncontested.
For climate change, he's letting all of the western provinces pollute as much as they want, since anyways, the eastern ones are reducing emissions, Canada can afford it! Hell, when Québec and Ontario announced ambitious environment initiatives, his minister CRITICIZED them for it!
The only thing Harper does is tax cuts, and most of them are only for the rich. While at the beginning I tolerated him because I appreciated that he actually fulfilled his promises (unlike the liberals), everything his party stands for is repulsive.