Environmental group Ocean Rebellion held a dramatic protest outside a key International Maritime Organization meeting on climate change.

The protest came as government delegates from around the world met online to debate new carbon emission reduction targets for shipping.

Outside the IMO's London headquarters protestors theatrically represented how they believe shipping regulators are under the influence of oil interests.

On the opening day of the Environmental Protection Committee (MEPC) meeting demonstrators played out a scene where figures representing oil interests handed out "dirty money" to the IMO and vomited oil.

"Dirty scrubbers" then arrived on the scene to clean up the mess, "with mops and buckets of greenwash, ensuring that the 77th MEPC could proceed undisturbed," said Ocean Rebellion in a statement.

The IMO has been contacted for comment.

Ocean Rebellion wants the IMO to agree mandatory carbon emission reduction targets for shipping by 2030.

Otherwise, it argues, the shipping industry will fall short of Paris Agreement targets on limiting climate change to 1.5 degrees.

'Dirty Scrubbers' show up to clean up the mess caused by oil interests in enactment of alleged support from the IMO for oil interests. Photo: Guy Reece

"Our demand is simple: Get Ships Off Fossil Fuels, to stop climate breakdown, prevent repeated negligent fossil fuel oil spills including in the Arctic, and to protect people's livelihoods, and our precious marine environments," said Ocean Rebellion's Sophie Miller.

"The IMO has a chance to turn things around. To make a real difference not just to marine life but to our survival as a species on this planet. But it needs to step up now. To get out of bed with the fossil fuel industry and stand up for the environment," she added.

The IMO is currently discussing proposals to set a target of net zero emissions by 2050.

IMO secretary general Kitack Lim told the opening session of the MEPC meeting that the organsation needs to respond to calls for increased emissions reduction targets following the recent COP 26 meeting.

"It is of the upmost importance that IMO continues to deliver concrete progress in transitioning shipping from fossil fuels to low and zero-carbon alternatives. It is our duty to join worldwide commitments of increased ambition toward tackling climate change," he told the meeting.

"Now we must be brave and let our industry lead by example," he said.