By Claire Marshall
BBC News, Costa Rica
In February 2008 , Norway, New Zealand, Iceland and Costa Rica made a commitment to go carbon neutral.
A key step is looking at agricultural practices
The tiny Central American country is the only developing country to have made the tough pledge to turn its economy green.
It has also set itself the hardest target with the government saying it will go carbon neutral by 2021.
"If any country can do it, it's Costa Rica," said Sergio Musmanni, who is helping to lead the government's new national climate change strategy.
"We have been at the forefront of the climate change issue for years. A large percentage of our electricity... already comes from renewable energy sources. And we are in the tropics. We don't have problems heating up our homes and buildings during the winter."
Some sectors are getting behind the idea.
At a plantation on the country's Caribbean coast, bunches of bananas, Costa Rica's biggest export, are encased in plastic while growing to protect them from insects and disease.
Rudy Amador, from the Dole food company, looks up at the pale blue cocoons being cut down with machetes.
"The first thing is measuring what the emissions actually are. Then we're looking at ways that we can do our agricultural practices better to reduce the emissions. In addition to production, we are also involved in transportation, so we are also looking at ways of being more fuel efficient," he said.
One of the keys to all attempts to go carbon neutral is to find ways to off-set emissions.
The Costa Rican government is attempting to do this through reforestation.
Costa Rica's fauna and flora are a draw for tourists
The government planted what it says is a world record five million trees last year, and is aiming for a new record of seven million this year.
The theory is that if enough trees are planted, they will absorb enough carbon dioxide to cancel out the country's emissions of greenhouse gases.
Many of the seedlings come from the Earth University, 80km (50 miles) east of the capital, San Jose.
The private, not-for-profit institution is in more than 3,000 hectares (7,400 acres) of breathtakingly rich and fertile land.
Professor Ricardo Russo is in charge of the reforestation programme. He gestures over a wide area of cleared land, where vivid green four-month old saplings are thrusting in to the sky.
"You can see the growth here in the tropics. It's incredible. In four months, they can grow 50 to 60cm."
Professor Russo believes that planting trees is a good way to stop the planet heating up.
"The tree starts absorbing carbon dioxide from when it's a seedling. Especially during the first 10 to 15 years, it's a very efficient way of absorbing carbon from the atmosphere".
Costa Rica already has some progressive environmental policies. More than 30% of the country has been given over to national parks, and the country pioneered the concept of eco-tourism in the region.
However, some voice doubts over the tough time limit that the country has set itself.
"Costa Rica has been the only country in Central America ahead of everyone else, in terms of protecting the environment," said Jose Vasquez, from the World Wildlife Fund.
"I believe this is the first step to mitigate even more the impact they have on climate change. The only thing I see is a little bit problematic is by 2021. It's a huge target."
There is one overwhelming issue that needs to be addressed, particularly for a developing country.
"The real challenge for Costa Rica is transportation. Most of our emissions come from this sector. We really have to start making changes in how Costa Ricans are moving, but as the economy grows, if more people want to have their own cars, we have to take that in to account," said Mr Musmanni.
There is one example from private industry. Four years ago, Nature Air began moves to become a carbon neutral airline.
Costa Rica has set itself a tight target for going green
Sitting back in one of the company's Twin Otter planes, chief executive Alex Khajavi looks down fondly at the Pacific coastline, the emerald hills folding down to long white strips of beach.
"We are in the right position in this country to be the crucible for the changes that the rest of the world is looking for. We cannot let it fail. We need to get everyone on our side to make this small experiment in something very radical but very necessary, to work," he said.
"We need to be an example to the rest of the world".
The Costa Rican government has given itself just 13 years to turn its economy green and become that example.