Scientists from around the world were gathering in Monaco on Wednesday to release a major report on the impact of global warming on the Earth's oceans and frozen regions.
The Intergovernmental Panel on Climate Change (IPCC) scoured almost 7,000 scientific publications to come up with an overview of the effects of greenhouse gases on oceans, glaciers and permafrost regions.
Hours ahead of the release of the report, French President Emmanuel Macron said that it contained "naked and stubborn" facts.
"We are losing the battle," he told the United Nations General Assembly in New York on Tuesday.
The report comes weeks after the U.N. panel warned of the impact of climate change on land, saying that the world faced a high risk of drought, wildfires, thawing permafrost and unstable food supplies.
The IPCC warned last October that limiting global warming to an average temperature rise of 1.5 degrees Celsius above pre-industrial levels is only possible with "rapid, far-reaching and unprecedented changes."
The IPCC is a U.N. institution with 195 member states. Its reports aim to summarize scientific knowledge on climate change and offer advice to policymakers.