Scores of Londoners are expected to attend the Global Climate Change rally in Victoria Park Sunday.
It runs from 2 p.m. to 3 p.m.
The event will feature a petition signing and march around Victoria Park.
Rallies are being helda across the world to urge governments to committ to legally binding targets to reduce green house gas emissions.
The rally is being held ahead of the United Nations conference on climate change, called COP 21, which begins on Monday.
