Alexandria Ocasio-Cortez delivers emotional climate change speech

US Representative Alexandria Ocasio-Cortez has delivered a powerful climate change speech in an address to mayors of 94 leading world cities.

The 29-year-old was invited to speak at the C40 World Mayors summit in Copenhagen on Friday, where she highlighted that the world's most advanced and richest economies are failing to take sufficient steps to combat climate change.

"It is unsustainable to continue to believe [in] our system of runaway, unaccountable, lawbreaking pursuit of profit," she told the conference.

"Our current logic created this mess and operating in the same way will not get us out."

The US withdrew from the Paris Agreement in 2017, which deals with greenhouse-gas-emissions mitigation, adaptation, and finance. However, Ocasio-Cortez noted that other nations are still not taking action, despite being part of the Paris Agreement.

"The United States, to the horror of the world, withdrew from the Paris Agreement," she said.

"But despite that, many of the other actors in charge of some of the most advanced and wealthiest economies have withdrawn from the agreement in action. Not a single one is on track to meet their Paris goals."

Ocasio-Cortez's voice began to crack as she spoke about the future of any children she may have, stating that it is the current population's responsibility to steer the world away from such jeopardy.

"On this note I speak to you, not as an elected official or public figure, but I speak to you as a human being, a woman whose dreams of motherhood now taste bittersweet because of what I know about our children's future and that our actions are responsible for bringing their most dire possibilities into focus," she said.

"I speak to you as a daughter and descendant of colonised peoples who have already begun to suffer."