No, it's not a hoax.

Climate change is real and has been going on since the earth first formed.

There are of course natural cycles and rhythms that the Earth goes through. It heats up, it cools down. This is why there have been multiple ice ages (the last one approx 10,000 to 13,000 years ago) and then the Earth heats up and the ice melts.

This is simply the natural cycle that the planet goes through. The question about whether humans are CAUSING global warming is absurd when looked at over a great time period. We are not causing it because it was already occuring. We are however greatly hastening the effects and in essence shortening the cycle. This will have the additional effect of throwing more things out of balance and could cause greater unknown problems down the road that the Earth has not experienced before.