An agreement between countries that have pledged to cut back on the amount of greenhouse gasses they produce, will begin on Wednesday.
The world is getting more serious about the environment - but what about you?
Do you do your bit, either by turning the lights off, buying ozone friendly products or using recycled paper?
Perhaps you do all these things and more?
Or do you find it difficult to be environmentally friendly, and think more needs to be done to make it easier for you?
E-mail and let us know.
Unfortunately this topic is now closed but there are Comments pages on other subjects on the main Chat index.
I never used to switch of the lights when I left a room. But since my dad told me how it can cause global warming, now I always turn off the lights when I walk out of a room.
Peter, 11, Romsey
I have put up posters with my friend saying what will happen if you don't recycle and use cars less! It has worked little bit!
Emma, 9, Poole
My family and I are doing our bit by using our blue bin more - and my gran recycles like mad, bless her!
Alice, 11, Ipswich
People don't seem to care about the environment anymore. I don't know why there are still some countries that aren't signing up. It is a world problem so all countries should be involved in the solution. I'm talking about the big countries that are causing most of the pollution like the USA. It seems a bit selfish.
Laura, 14, Beer
I recycle and get the bus but I only recycle paper - nothing else as the bottle banks are always full so I think the council should give us bags for other items like aluminium cans and glass bottles which they collect every fortnight.
Jack, 12, West Midlands
I re-use loads of stuff, like a shoebox to put stuff in. I recycle paper and it's really easy for me because at school in each class there are 2 huge paper recycling bins. One for normal paper, one for office paper with the ink on so the ink can be recycled as well.
Sumaiyah, 11, Leicester
I will almost always walk when I need to get somewhere. Sometimes I take a train if it's too far. I try to encourage my friends to do the same. I also recycle everything from glass bottles to drinks cans along with the rest of my family.
Juliette, 14, Cardiff
I am making sure I don't drop litter on the floor and if I see someone I know doing it I tell them not to.
Ria, 13, Surrey
We recycle bottles and newspaper but not everything we can. We don't have a council service to pick our recycling but it's worse at our school no one recycles anything there!
Ann, 13, Birmingham
Our school has a recycling bin and everyday my class goes round, getting the blue boxes that every class has. We than take them all out to the big blue bin.
Emma, 10, Bicester
I sometimes get pencils and stationary that is made by recycled paper cups and newspapers, but really I don't see much of that anywhere.
Lisa, 13, Southampton
We recycle everything from paper to rotting fruit. We turn all lights off, and pick up our dogs poop!
Katie, 14, Rishton
I'm helping by doing litter pick at school and not breaking trees or climbing them or throwing litter to kill animals and nature.
Chloe, 12, New Milton
Where I live, out in the country, there aren't any special bins yet, though we are meant to be getting some, and we only get a bus once a week. In this way we can't really help the Earth, but my family do recycle, though we have to go to a local supermarket to do it.
Ana, 14, York
My school has been doing an eco schools project for 3 years. We have been designing and building our gardens and going out to plant wild flower seeds so there are more for birds and insects. We are also putting up posters saying don't drop litter put it in the bin. We are trying to go for the green flag because we have already won the bronze and silver award. We have also set up an eco-schools club after school to learn more about the environment.
Jenna, 11, Glasgow
My dad is a waste manager and we recycle with a black box and a brown bin. I think we should start to try and do our bit for the environment before it destroys our world.
Judith, 9, Armagh
My local council has brought out a recycling scheme - we now have a blue bin to put paper, boxes and leaflets etc and given houses compost bins and they're trying out bins to put glass in . It has been a great success.
James, 10, East Kilbride
Ever since I watched this programme about what's happening to the world all I can now do is turn lights off and recycle. I just wish the USA would sign up.
Evie, 12, High Wycombe
Our family are getting solar panels instead of electricity.
Rachel, 13, Oxford
I think people that can't be bothered to recycle are lazy as all they have to do is put some things in your green bin outside your house. If my teacher knew that people were too lazy to recycle she would be devastated because my teacher does a lot for the world, recycling and doing what she does.
Naomi, 10, Brithdir
I had a recycling project in school and at home we have a black box which we put our stuff in and then the council comes and takes it and recycles it. I think it is really important to recycle and look after the environment.
Caoimhe, 12, Armagh
I now NEVER throw litter on the floor and I ALWAYS turn off all of the things that don't need to be on.
Ed, 13, Lincoln
I recycle as much as possible, in fact I take a free newspaper just so I can recycle it. We use recycled paper products. I use public transport most of the time but to be honest I really don't do enough! I think we need to have a solar panel on every house!
Fi, 15, Bristol
My mum recycles the old newspapers that we have piled up in our house. We have recycle bins just round the corner from us which makes it easy to recycle.
Rebecca, 14, Essex
I do as much as I can to help the environment - I walk to school, use public transport whenever I can and I recycle plastic and glass bottles and paper.
Rachel, 13, Switzerland
I must admit; no. I litter a little bit, but not like everyone else, and I must admit I don't think about it that much.
Hannan, 14, Newcastle
No not really but instead of going in the car I walk with my friends to the beach, that kind of helps the environment right?
Samantha, 14, California
Our house really try and as far as we are concerned we do everything that we can.
I just hope other people try as hard.
Josie, 11, London
I am doing a lot to recycle. Turning off the stand-by on my television and using paper more wisely, instead of writing one thing on it then binning it, I cut it off and recycle it. I think everybody needs to do much more to save the environment though. The planet won't save itself you know!
Maisy, 14, Southampton
I am doing much more now that our council have made it easy to recycle by providing bags which they collect.
Steve, 13, Derby