The withdrawal of certain parties will not shake the collective will of the international community.

YOUTH activist Greta Thunberg berates world leaders at UN Climate Action Summit, accusing them of not doing enough action about climate change. AFP

UNITED NATIONS, United States (AFP) — An emotional Greta Thunberg tore into world leaders at a United Nations (UN) climate summit, accusing them of betraying her generation by failing to tackle greenhouse gas emissions, as announcements by major economies fell far short of expectations.

The Swedish teen’s impassioned speech, in which she repeated the words “How dare you” four times, was the defining moment of the meeting, called by UN chief Antonio Guterres to reinvigorate the faltering Paris climate agreement.

Ahead of the conference, the United Nations issued a release saying 66 countries vowed to achieve carbon neutrality by 2050, along with 10 regions, 102 cities, and scores of businesses.

But pre-summit predictions of new, headline-grabbing commitments, particularly by the likes of China and India, failed to match reality, angering environmental groups.

The world’s top scientists believe long-term temperature rise must be limited to 1.5 degrees Celsius over pre-industrial levels to prevent runaway warming with catastrophic effects.

But rather than peaking, the level of emissions being released into the atmosphere are at an all-time high, triggering global weather hazards from heat waves to intense hurricanes and raging wildfires.

New data released Monday showed the 2019 Arctic sea ice minimum is ranked at second-lowest in the 41-year satellite record, effectively tied with 2007 and 2016.

“I shouldn’t be up here. I should be back at school on the other side of the ocean,” said Thunberg, 16, who has become the global face of a growing youth movement against climate inaction that mobilized millions in a worldwide strike on Friday.

“You come to us young people for hope. How dare you?” she thundered, her voice at times breaking with emotion.

Matters did not improve much as a succession of national leaders took to the podium saying they understood the gravity of the situation but then failing to announce concrete plans.

Indian Prime Minister Narendra Modi did not say explicitly whether his country would enhance its commitments made under the Paris agreement — though he did say it was working on more than doubling its renewable energy capacity.

There was also no new announcement by China, the world’s biggest emitter. Senior foreign policy official Wang Yi spoke instead about the need for multilateralism, taking a veiled swipe at US President Donald Trump for pulling out of the Paris accord on taking office.

“The withdrawal of certain parties will not shake the collective will of the international community,” he said.