There is a National Climate Change march this saturday if you are in London as part of the Global Action Day.
There are four main themes
1) NO to a 3rd runway at Heathrow and the runaway expansion in aviation expansion.
2) NO new coal - no new coal-fired power stations as planned at eg Kingsnorth in Kent
3) NO to the expansion of agrofuels - with negative impacts on forests, the climate and world food supply.
4) YES to a renewable energy revolution and green jobs - a "Green new Deal"
For more information see links above.