Hello ladies and gents this is the Viking telling you that today we are talking about

SAVERS OF THE WORLD

Rebecca Hosking

Camera operator

Rebecca Hosking, 33, is the young BBC camerawoman who went to an atoll in Hawaii, found wildlife dead or dying after ingesting bits of plastic, and returned to the small town of Modbury in Devon with a fine film, and a desire to try to ban plastic bags. In May 2007, the town became the first in Europe to go plasticfree and since then at least 80 other places have decided to follow suit. 

London Councils, the umbrella group for 33 local authorities, aims to reduce the 4bn plastic bags sent to landfill from the capital each year and has proposed a law that would force shoppers to use their own bags or buy reusable ones at the tills. Hosking has clearly tapped into a new public mood and has found that there is no need to wait for governments to effect change. Just do it yourself.

Wangari Maathai

Environmentalist

No one can doubt the persuasive powers of Wangari Maathai, Nobel peace prize-winner and 67-year-old former assistant minister of the environment in Kenya. It is she who has coaxed the Mexican army, Japanese geishas, French celebrities, 10,000 Malaysian schools, the president of Turkmenistan and children in Rotherham to roll up their sleeves, dig a hole and plant a tree.

It was an off-the-cuff remark of hers in 2006 that led to this far-flung initiative. She was in the US accepting an award when a businessman told her that his company was planning to plant a million trees. Jokingly, Maathai, who has spent most of a lifetime planting saplings, responded, "That's great. But what we really need is to plant one billion trees." The UN - and the Green Belt Movement Maathai founded among African women - picked up the challenge.

In just over a year, in one of the largest mobilisations of people for a cause since the Asian tsunami, 1.5bn trees have been planted in nearly 50 countries, and a further billion more are pledged. Countries have fallen over themselves to plant the most and be linked with Maathai: Indonesia planted 79m in a day; Turkey says it has planted 500m, Mexico 250m, and India says that it will replant six million hectares of degraded forest.

Many of these saplings may not survive more than a few weeks, and the numbers are not to be trusted, but the billion tree campaign shows that Maathai - a professor of biology and mother of three children - has gone from being almost unknown in 2003 to a global treasure in just a few years. There is now barely a president or prime minister in Europe, Asia or Africa who has not invited Maathai to endorse their plans or tried to sign her up as a goodwill ambassador to show off their newfound enthusiasm for the environment. 

She has addressed the UN general assembly, carried the flag at the Olympic games, and received sackfuls of citations and awards. Maathai has succeeded in putting deforestation high on the agenda in developing countries, just as Al Gore made people in rich countries aware of climate change.

She has made tree planting an act of transformation in which everyone can engage. "The planting of trees is the planting of ideas," Maathai says. "By starting with the simple step of digging a hole and planting a tree, we plant hope for ourselves and for future generations.

"The first steps were really to talk to women," she explains, "and to convince them that we could do something about their environment. They didn't have firewood, they didn't have clean drinking water and they didn't have adequate food. A tree brings transformation."

Peter Garrett

Politician

Peter Garrett, 54, is the former punk lead singer of the disbanded Australian rock group Midnight Oil, who continued his weird journey from radical muso to establishment politician when he was appointed Australia's environment minister. 

He began with gigs outside Exxon offices and protests at the Sydney Olympics about Aboriginal rights, and found himself labelled a turncoat by some at the election. However, he was nominated here by Jonathon Porritt, for being "instrumental in shaping the Australian Labour party's climate change and environment policies". Within days of his taking office, Australia signed up to the Kyoto climate change treaty, and has broken with the obstructivist policies of President Bush.

And as always have a chilled day from the Viking