Britons have braved the rain to rally by the hundred for climate action in the shadow of the iconic London Eye, Elizabeth Pearson reports from London.

Protestors donned coloured wigs and blew whistles as they formed a giant number five with their bodies on the south bank of the Thames, one of more than 5000 campaigns held across the globe to mark the International Day of Climate Action.

London’s human numeral corresponded with threes, fives and zeroes made in Australia, New Zealand and China to call for carbon emissions to be cut to 350 parts per million.

“What I love about 350 is that the message is so simple, based entirely on science,” said London event organiser and computer programmer Nik Smit.

“I’m a grassroots campaigner and there’s no overt political stuff about this, it’s not huggy-feely. It provides a great yardstick for knowing where we are, where we need to be and what we need to do.”

NASA scientist Dr James Hansen warned that the world must reduce its carbon dioxide emissions to 350ppm to avoid catastrophic climate change in 2008. The practice of burning fossil fuels has driven current levels beyond 380ppm.

The 350.org campaign founded by author and environmental campaigner Bill McKibben called for political leaders to make this their target at the upcoming UN climate summit in Copenhagen.

“It looks like an agreement is going to be difficult but that doesn’t mean that Copenhagen is a disaster or that these campaigns aren’t worthwhile,” Smit said.

“These campaigns all frame the debate based on science, which is what we need.”

Roselle McLeod from Ipswich joined thousands of people from 180 countries around the globe in campaigning for climate action.

“Whatever happens to the climate happens to the world and to my part of the world,” she said.

Northwood resident Menka said the timing of the protests was crucial.

“Leaders are coming together to make important decisions and I think it would be good if they were able to see beyond the current economic climate as I think the urgency around climate change has gone off the radar due to the recession.”

“I feel like there’s a lot going on around climate change and it can be quite confusing for all of us. So [to] pick out one piece of the story and really focus on that- I think that’s a really good move,” she said.

Participating in the London protests, Heiz Jerstaz from Norway said European nations will need to set a positive example at the talks in December.

“I think that first world countries do have the responsibility to make major [emissions] reductions in comparison to the others,” she said.

Elsewhere in London, activists donned their wellies and waded into the Thames downstream while shoppers on the exclusive Regent Street formed an extended paper chain with a personal environmental pledge written on each link.

Nik Smit said these campaigns were all important ways for the British public to voice their objection to climate change.

“It’s up to us to reduce our emissions in the home but it’s also up to us to stand up and say this is how we feel and this is what we need so when policy is made in Copenhagen, it reflects what the majority want,” he said.

British Prime Minister Gordon Brown is one of few world leaders to have committed to attending the Copenhagen climate conference in person.

GEJI reporter Liz Pearson is on exchange to City University, London from the University of Technology, Sydney.