Scientists, world leaders and officials have all gathered in Copenhagen in Denmark for what's been described as the most important meeting in the world.
Newsround's Leah is taking a closer look at the effects of global warming and what we can all do to help the environment.
"Experts say that that to be kinder to the planet, it might help if we all cut down on the amount of time we spend in the shower.
Trying to do this has been pretty hard because I'm a fan of singing in the shower, even though it doesn't sound too good. But I've got a timer on my phone to remind me when I need to jump out.
I use public transport to get to work everyday - in my case I use London Underground - but I also drive a car at weekends to go shopping or visit friends.
Recently at weekends I've been using the bus and trains to get about and actually I prefer this much more because I am avoiding getting stuck in traffic jams. I'm even thinking about selling my car in the new year too!
Leah decided to spend less time in the shower.
One of the other things I've been trying to do this week is making sure I close all doors and windows.
By trapping the heat inside the house I'm keeping things nice and cosy, plus I'm also saving money on energy bills because I don't have to crank up the heating.
This was something I picked up from the guys I met at the energy efficient school in Durham.
I've found that I am thinking more about the decisions I make when it comes to switching off TVs or jumping on the bus instead of using my car - small things that I hope will make a difference. It's also been great fun."