You're not missing anything important, it's just a perfectly legal march, approved by the local authorities and the police, involving no direct action and ensuring all the participants go home feeling like they have done something.

If you really want to do something about climate change then one important step is not to waste your time on symbolic non-actions.

I shall be getting on a coach tomorrow morning from south wales and travel the 300 plus mile round trip to London in a vehicle that travels at around 25 miles per gallon of diesel.I shall then march from A to B in an orderley stewarded procession agreed to by the authorities in advance,with my placard given to me by an orginsation/political party with thier slogan printed on it so I don`t have to think for myself(phew).During this time I will shout slogans dictated to me by orginisiers and listen to speakers,mainly political puppeteers and puppetts after thier own personal political agenda and I will buy political papers and pamphlets usually from the kind of people who call for the dictatorship of the working classes. With the multitudes that turn out I will truly beleive that my voice has been heard and that things will change,after all,after millions marched against the war in cities all around the world, we acheived............absoloutly nothing. I will then join the convoy of coaches leaving London to spew out diesel fumes all over the countryside. I will return home satisfied and less guilty and angry about polluting the planet feeling I have done my bit. I will then endevour to carry on my polluting lifestyle until the next big gathering of the species who pollutes this planet decides to get together. Of course if I were to be told that our political masters deemed this illegal of course I would not turn up,just as a shop steward from Unison will not because he fears his job may be in jeporady if his bosses finds out he`s been on a demo.................Very militant.

this demo takes place at a time of year when everyone is completely wrapped up in mindlessly consuming the world to death by buying worthless chinese rubbish presents for people who do not need such so numbers will be way way down compared to absolutely any other time of year. there is negligible chance of any bystanders in the west end joining in or even showing interest because they will be too busy worrying what to buy for aunt jemima. the weather is likely to be dismal; last year it was driving rain for the entire day so the marchers looked like so many unhappy drowned rats and the march as a whole had zilch appeal. also because the date is so close to the solstice, it will become dark well before the march is over, people will be listening to speeches in the dark and photos and videos of the event for the world's media will be gloomy looking.

i am really really sorry to knock the demo like this but climate change is just so important, far more important than the self inflicted credit crunch, recession, terrorism, wars and christmas crap. so why oh why hold a protest on such a serious issue at a time of year that absolutely guarantees really piss poor turnout and lack of coverage by the media? phil thornhill - national co-ordinator of campaign against climate change, how much longer are you going to waste your campaign's resources by stubbornly clinging to this time of year for your big bash simply because it has always been so? that is not a good reason at all.

i do actually urge everyone to go on this march despite me and others carping because the issue is just too serious to ignore. here are the details for the original poster.
 http://www.campaigncc.org/

I think it would be very useful for the long term viability of the campaign, that when phil thornhill himself speaks, for him to receive some heckling, criticising the choice of time of the year and urging the change to a more sensible month.