By Ellen Wulfhorst

NEW YORK, Sept 11 (Thomson Reuters Foundation) — Growing inequality and climate change will not only derail progress towards global sustainability goals but threaten human existence, leading scientists said at the United Nations on Wednesday.

The world is falling off track on ambitious global development goals adopted by UN members, a panel of scientists said in an independent assessment report released at UN headquarters.

Member nations unanimously adopted 17 sustainable development goals known as SDGs in 2015, setting out a wide-ranging "to-do" list tackling conflict, hunger, land degradation, gender equality, and climate change by 2030.

The bleak assessment report was released ahead of a sustainable goals summit scheduled at the United Nations for later this month.

"Overall, the picture is a sobering one," said Shantanu Mukherjee, policy chief at the UN Department of Economic and Social Affairs.

"One element of this is increasing inequality .... Another is the pace at which nature is being degraded by human activity, whether it is climate change or biodiversity loss."

Read More: Climate Change Is Threatening the Fight to End Extreme Poverty: UN

The independent panel of scientists investigated the ways and systems in which humans and the environment are linked and interact, said Peter Messerli of the University of Bern, Switzerland, the co-chair of the group of scientists.

"These systems are on a very worrying trajectory, threatening the very existence of humanity," he told reporters. "We have not realized the urgency to act now."

Countries must put into practice ways to address vast gaps in wealth distribution and access to economic opportunities and technological advances that undermine innovation and economic growth, the report said.

"Each country has to decide," Jean-Paul Moatti, chief executive of the French Research Institute for Development and one of the scientists who compiled the report.

"This has to be corrected," he told the Thomson Reuters Foundation.

The report called on nations to focus on food and energy production and distribution, consumption and urban growth to find ways of building sustainable development.

The cost of implementing the global goals has been estimated at $3 trillion a year.

These are not the first grim predictions made for the fate of the goals.

Read More: What Are the Global Goals — and How Close Are We to Achieving Them?

Earlier reports have said they were threatened by the persistence of violence, conflict and destabilizing climate change.

Outside assessments have cited nationalism, protectionism and a need to obtain more funding, ease national debts, boost wages and expand trade.

(Reporting by Ellen Wulfhorst, Editing by Claire Cozens. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's and LGBT+ rights, human trafficking, property rights and climate change. Visit http://news.trust.org)