Newsround meets Prime Minister Gordon Brown
Newsround has been inside Downing Street to interview the prime minister.
Leah and Press Packers Navir and Arian went to Number 10 to meet Gordon Brown just before he left for the big climate change conference in Copenhagen.
The PM told them that he's trying to use less electricity at his house in Scotland by using more eco-friendly solar energy.
He said: "We're generating our hot water from a solar panel and we have to encourage more people to do that."
The prime minister has gone to Copenhagen two days early to try to help world leaders agree on a deal to reduce the the number of poisonous gases released into the atmosphere.
But wouldn't it be better for the environment if they got together on webcams instead of all flying there, which uses lots of fuel?
Mr Brown told Leah: "I've just done a video conference with President Obama, but sometimes you have to get together.
"When it's a really difficult issue you need to be direct with people and its easier to do that when you're in the same room. "
Some people are worried that even with all the world leaders in one place, they might not be able to agree on a deal to reduce how much carbon dioxide is produced.
The PM agreed, but said he's still hopeful.
He added: "There is a lot of tension, because the poorer countries feel they didn't cause the problem and that it's the industrial countries that have done this.
"But if we do the right things, and make the right plans, I think we can get a solution."