On the Global Day of Action on Climate Change, activists laid a fake pipeline from the US to Canadian embassies, before marching to Parliament to erect a giant mock fracking rig with the message 'No Fracking in the UK'.
The protest aimed to highlight the dangers of using shale oil and tar sands for energy, both of which would lead to excessive global warming and make reaching the targets set for carbon emissions impossible. Other concerns related to climate change were also represented in banners, placards and posters, including the melting of Arctic sea ice - now expected to disappear completely in the summer by 2015 and the dangers of nuclear energy, made very clear at Fukushima, with a number of Japanese anti-nuclear activists taking part in the protest.
The event started with a short rally outside the US Embassy, chosen because the dirty energy lobby in the USA, led by companies including the Koch Brothers, has succeeded in making the US the main barrier to effective climate action over the years. Their success led to an effective total silence over climate change as an issue in the recent US election - until Hurricane Sandy forced it onto the agenda at a very late stage. The US is also a leader in 'fracking', going ahead with it a full speed despite the problems of contamination of water tables it has been shown to cause.
At the end of the rally people began to collect the long 'pipes' to build the pipeline from the front of the US embassy to the Canadian Canadian High Commission at the opposite end of Grosvenor Square to show their outrage at the continued exploitation of high-carbon tar sands. There were just about enough pipes to stretch the length of the square - about 250 metres, but it wasn't really possible to see the whole thing as it had to go along the pavement rather than through the gardens in the centre.
The march then formed up along the side of the square, with around a thousand people, and set off towards Berkeley Square and then past Piccadilly Circus to Trafalgar Square and Whitehall to Parliament.
I had left the march soon after the start to photograph some other events, and returned to Old Palace Yard just before the mock fracking rig was raised. After this the rally there continued with speeches from Eve Macnamara from REAF (Ribble Estuary against Fracking), John McDonnell MP (Labour, Hayes and Harlington) and Natalie Bennett (leader, Green party).