Better them disrupting the streets of London than those streets awash with floodwater from an ever-rising Thames.
Has it ever occurred to those who poo-poo concern with climate change that there are two possible scenarios ahead?
1) Everyone listens to the predictions, does their best to understand them, and then alters their lifestyles to leave as small a footprint as they can. Governments listen and pass legislation that makes it an advantage to act to prevent the predictions being fulfilled and a disadvantage to continue adding to the problem. Those who see that their government is not taking any of these measures make a hell of a noise about it and persuade them to take action.
Result - global climate warning is arrested, the earth does not reach a critical and irreversable stage, all is well, and the sceptics say "See - there was no need to worry and take all that trouble after all. It never happened! What a waste of time and effort doing all that protesting and cleaning up!"
2) Starts with people saying "Shere is no point in taking the trouble to protest and causing inconvenience. It may never happen!" So protesters don't protest, no-one is inconvenienced, governments go their own sweet way, those who don't bother about climate warming continue not to worry. Thins go on as before. ~The efforts of the converted are not enough, the global temperature gradually increases, gaining speed as the feedbacks feed in and heat causes changes that generate more heat.
Result - It gets too late to reverse.
Heads in the sand only see the coming sandstorm from below the dunes that cover them.