At the UN Climate Summit that started on Monday, December 2, in Madrid, Spain U.N. secretary-general Antonio Guterres urged delegates to choose hope over surrender in fighting against climate change.

In the opening session, Guterres asked delegates if “we really want to be remembered as the generation that buried its head in the sand, that fiddled while the planet burned?”

“One is the path of surrender, where we have sleepwalked past the point of no return,” he said.

“The other option is the path of hope. A path of resolve, of sustainable solutions.”

The two-week summit aims to address pending issues on carbon trading to reduce emissions and solidify international commitment to radically change energy, transport, and industry to wean the world from its dependence on fossil fuels.

Pledges made under the 2015 Paris agreement, which unites all nations to fight climate change and strengthen efforts needed for a sustainable low carbon future, still lacks transformational action that is required to prevent devastating climate disasters. The aim is to keep global temperature rise below 2 degrees Celsius and limit the temperature increase to 1.5 degrees Celcius.

The Paris agreement implementation is also facing challenges as President Trump formally pulled out of it a month before the summit. USA is the world’s second-largest emitter of carbon dioxide from fossil fuel combustion, next to China. But the US isn’t fully out of the agreement yet as it takes another year for the withdrawal notice to become official. U.S. House of Representatives Speaker Nancy Pelosi, who leads impeachment proceedings against Trump in Washington, was present at the summit, conveying that the Congress was committed to taking climate action.

Spain’s acting Prime Minister Pedro Sanchez encouraged delegates to be daring, saying that “No one can independently pull out of this challenge” and that “There is no wall high enough to protect any country from this challenge, however powerful they are.”