The former president of Ireland Mary Robinson has called on developed nations to cut their consumption levels.
Mrs Robinson, 72, negotiated with world leaders ahead of the Paris Agreement on climate change, arguing strongly for "climate justice", and speaking at the One Young World Summit in Ottawa, Canada, she once again stressed the need for change.
"We don't need to consume as much as we have in the world," she said. "We have a world where there's inequity and inequality. We can be simpler in the parts of the world that have benefited from fossil fuel."
Mrs Robinson used the number of toys her grandchildren have as an example of over-consumption, adding:
"We have to change, we cannot go on with business as usual. We need each of us to think about our carbon footprint. Eat less meat, or no meat at all. Become vegetarian or vegan.Let's commit to the Paris agreement. Let's commit to leave no one behind."
The former United Nations High Commissioner for Human Rights was speaking at the summit, which brings 1,300 current and future young leaders from 196 nations together in order to discuss issues ranging from peace and security to business and education.
The president of the Irish Creamery Milk Suppliers Association (ICMSA) has said that Mrs Robinson's call for people to reduce their carbon footprint by eating less meat or none at all is "facile sensationalism".
Deciding whether it's "necessary or desirable to fly around the world from seminar to seminar urging others to give up meat and dairy for the planet's sake", should be the former Irish president's concern, John Comer said.
"It's just a fact, for instance, that milk production places less stress on the environment in Ireland, by virtue of our grass-base, than almost anywhere else in Europe or the world. That wouldn't be true of other staples and we might see the merit in specialising according to environmental suitability."
He added: "Mrs Robinson is of course entitled to her views but we'd expect them to take reality as their starting point. This is the greatest challenge facing mankind and there's no room for this kind of facile sensationalism we saw from Mrs Robinson in Ottawa."