(CNN) -- "We are reaching the tipping point and the tipping point according to most scientists will be in less than 10 years. We don't have much time," says human rights and environmental campaigner, Bianca Jagger.
At the Rio+20 Earth Summit, the former actress and model is hoping to speed up climate action by supporting "Plant a Pledge," a campaign to promote the Bonn Challenge -- a global initiative to restore 150 million hectares (an area almost three times the size of France) of degraded land by 2020.
"It's a project that will bring concrete and tangible change to people, to the environment and to the economy and will make a difference to the way we are tackling the issue of climate change," says Jagger.
The Bonn Challenge was launched in September last year with the aim of helping achieve the goals of the United Nations REDD+ program and Target 15 (there are 20 in total) of the Convention on Biological Diversity, which was signed by 150 governments at the first Rio Earth Summit in 1992.
Organized by the International Union for Conservation of Nature (IUCN) in association with European aerospace company, Airbus, "Plant a Pledge" is urging governments, businesses and environmental experts to help create what is being billed as the world's biggest restoration project.
"Just think about transforming a landscape that is barren to a landscape where you will be able to make the land fertile, where it can be sustainable, where agriculture can come back, where people can benefit," she said.
If fully implemented, the Bonn Challenge could inject more than $80 billion into local and global economies, according to the IUCN.
It could also cut the emission reductions gap by up to 17%, the IUCN says.
Scientists estimate that carbon dioxide emissions need to be restricted to 44 gigatons annually by 2020 to prevent global temperatures rising above two degrees Celsius (3.6 degrees Fahrenheit) during the 21st century.
Current predictions suggest that limit will be exceeded by nine gigatons, according to the U.N.
Jagger and the IUCN's efforts were rewarded at the Rio+20 this week with commitments from the U.S. government, Rwanda, Brazil and indigenous groups from Mesoamerica to restore more than 18 million hectares of forest.
The U.S. will restore the lion's share of that number, pledging to re-plant 15 million hectares of land.
"Many governments are already convinced this will bring financial benefits for their country and they know we will be tackling the issue of food security, we will be improving water sources," Jagger said.
"At the same time, I see a lot of governments don't seem to fully understand the threat of climate change and they use the excuse we are living through an economic crisis or a difficult time to not do what is necessary," she said.
"We need to do it now, or we will all either live and survive together or we will all perish together. I don't think I am being alarmist. We need to make a difference and we as individuals can make that difference."
A veteran of the first Earth Summit, Jagger watched the Kyoto Protocol being born, but she fears for its future.
The agreement to reduce greenhouse gas emissions adopted in 1997 is due to expire in December with "no promises in sight," she says.
"There is so much we still need to do. Climate change is a reality and we are not doing enough for our planet, for our children, for future generations," she said.
"I wish there were more legally binding treaties that are for signature, especially as we go to Rio, but perhaps something will come out that is positive, I hope."