GLASGOW, (Reuters) – A U.N. conference is crucial to preventing the worst effects of climate change. It was launched amid acrimony Monday following accusations that major industrialised countries had slowed down in making ambitious new pledges.

The COP26 conference will be held in Glasgow, Scotland. It comes a day following the failure of the G20 major economies to agree to a 2050 deadline to halt net carbon emissions – a marker widely cited by many as a requirement for avoiding the worst global warming.

Their talks in Rome, however, only acknowledged “the key relevance of halting net emission “by or about mid-century”, did not set a timetable to phase out coal domestically, and diluted their promises of cutting methane emissions, another greenhouse gas.

We call on all people to recognize the urgency of the climate crisis. It’s not next year. It’s not next month. Greta Thunberg (a Swedish activist) tweeted that she was asking her millions to sign an open letter in which leaders are accused of betraying.

These leaders are expected to take the podium in Glasgow Monday morning to defend and make additional pledges during the opening of the negotiations, which host Britain describes as “make-or-break”.

Boris Johnson, British Prime Minister, stated to reporters that COP26 must not be a failure.

The level of animosity among the largest emitters in the world will make it difficult. U.S. President Joe Biden criticised Russia and China for not making proposals.

“The disappointment relates to the fact that Russia and … China basically didn’t show up in terms of any commitments to deal with climate change,” Biden, who faces domestic resistance to his climate ambitions, told reporters at the G20.

An official schedule indicates that the Chinese President Xi Jinping is scheduled to address the conference in a written speech on Monday.

COP26 has been delayed for a year by the COVID-19 pandemic. It aims to maintain a target to limit global warming to 1.5C above preindustrial levels. Scientists believe this would protect us from its most devastating consequences.

This conference should secure greater ambitions for emissions reduction, climate financing in the billions, and finalize rules to implement 2015 Paris Agreement. Nearly 200 countries have signed it.

Current pledges to reduce emissions will see the average global temperature rising by 2.7C in this century. This, according to the United Nations, would accelerate the damage that climate change has already caused. It would increase storms and expose more people to heat waves and floods.

COVID-19 is a unique feature of the U.N. Climate Conference. 25,000 participants must wear masks and socially distance themselves from COVID-19.

Following two days of speeches from world leaders beginning Monday, technical negotiations will follow. Most likely, any deal will be made within hours or days of the event’s November 12 end date.