LONDON, Aug 19 (Reuters) - Environmental activists who caused days of traffic chaos in London two years ago said on Wednesday they would start a fortnight of action next week focused on the capital"s financial district, which they blame for helping to fuel climate change. Extinction Rebellion (XR), which has regularly staged demonstrations across Britain targeting banks, financial institutions, energy firms and media organisations, said it expected thousands of activists to take part its "disruptive" protests which will start on Monday. "We"ll be targeting the City of London because it"s time that people understand the real contribution of the UK to this crisis," lawyer and XR activist Tim Crosland told reporters. "The City of London is the arch financier of the carbon economy. It supports 15% of global carbon emissions. It hosts BP, Shell, Glencore, Anglo American, and Russian oil and gas companies such as Gazprom and Rosneft." Extinction Rebellion brought much of central London to a standstill during 11 days of action in 2019, bringing its cause to the fore but also provoking criticism from some politicians who said the police had been too tolerant. The planned "Impossible Rebellion" will involve site occupations and marches through the capital"s financial district. The group declined to give any details of targets, but said there were no plans to target public transport. The action will coincide with a planned strike by a rail union next week which the capital"s transport operator said could cause major disruption. read more Extinction Rebellion wants an emergency response from governments and a mass move away from polluting industries to avert the worst scenarios of devastation outlined by scientists. A report from the Intergovernmental Panel on Climate Change (IPCC) earlier this month warned global warming was dangerously close to spiralling out of control, with U.N. Secretary-General António Guterres calling it a "code red for humanity". read more Britain will host the United Nations COP26 climate conference later this year, which will try to wring more ambitious climate action from governments and the money to fund it. read more Other Top Environment stories Swiss can easily afford net zero transition with 2% GDP outlay - study "Painful days ahead" as Haitians struggle to count lives lost in quake "Down to nothing" - dry, heavy winds stoke growing California wildfires Morgues fill to capacity in Haitian town hard-hit by quake After delays, UN biodiversity agreement expected next year Greek firefighters battle growing forest blaze near Athens Reporting by Michael Holden; Editing by David Holmes Our Standards: The Thomson Reuters Trust Principles.