Global warming

The best time traveling in Northern America is in summer because long day time. However, the global warming is worse. I worry no more winter in future. I have talked to my friend that I was planning to go to his place in Canada next year to experience how cold it was. I would like to see polar bears before they disappeared in the world. He told me that it was really not so cold compared with ten twenty years ago. So we must save our earth without any delay.