Market Forces, an organisation advocating for environmentally sustainable behaviour from corporates, put forward two resolutions, resolution 18 to amend the Rio constitution to allow non-binding advisory resolution and resolution 19 regarding disclosure on transition plans consistent with the goals of the Paris Agreement.

Rio flat out rejected the resolution 18, with chairman Simon Thompson telling the meeting it was likely to cause uncertainty regarding the authority of directors.

It wasn't as dismissive of the resolution 19.

"We agree with large parts of this resolution," Thompson said.

While Rio said it was working on short, medium and long-term targets to reduce scope 1 and 2 emissions, it had no control over scope 3 emissions as they were the responsibility of customers.

Market Forces executive director Julian Vincent said Thompson's claim the company couldn't tell customers to set emissions reduction targets was "disingenuous and misleading".

Thompson said Rio was committed to assisting the world in the transition to lower emissions reduction.

He pointed to Rio's main purpose: producing materials for human progress.

"It is our judgement steel is essential to human progress," Thompson said.

"Unless we're going to freeze the development of the world in its current state, we will need to produce steel."

Rio is a major producer of iron ore, but recently exited the coal business.

"We would argue coal is not essential to human progress," Thompson said.

"There are technically feasible alternatives to using coking coal in steelmaking.

"In the case of steel, there are no obvious substitutes in a whole range of applications.

Thompson said Rio was committed to assisting with the decarbonisation of the steelmaking process.

"But we don't make steel - our customers make steel. What we cannot do is set hard targets for steel mills," he said.

Just 2.36% of Rio shareholders voted in favour of resolution 18, while 6% voted for resolution 19.