A leading climate scientist and advisor to Saudi Arabia’s ambitious NEOM megacity has issued a stark warning that its massive construction plans could dramatically alter the region’s local weather patterns and environmental stability.

Donald Wuebbles, a professor of atmospheric sciences at the University of Illinois and a specialist in atmospheric physics and chemistry, told the Financial Times that he has repeatedly raised serious concerns about the environmental implications of the NEOM development.

As a paid member of the project’s Sustainability Advisory Committee, Wuebbles said he cautioned against the potential for The Line—a vast mirrored linear city—along with floating islands and a desert ski resort, to disrupt natural climatic conditions in the area.

“Part of my concern was, what impact is The Line and those [projects] going to have on the local environment,” Wuebbles said. “You start affecting the local weather and climate.”

He noted that such effects could include altered rainfall patterns, intensified wind and storm activity in the desert region, and other unforeseen consequences that have not been studied in sufficient detail.

NEOM, billed as Saudi Arabia’s flagship Vision 2030 project and projected to cost nearly $9 trillion, aims to transform a vast swath of the northwestern desert into a high-tech hub powered by renewable energy.

However, its scale and ambition have drawn scrutiny, not only from environmental experts but also from within the project’s own governance structure.

Wuebbles highlighted the significant carbon footprint associated with the use of cement in NEOM’s extensive construction, particularly for The Line, which has been described as the largest building site in the world. “The emissions from that much cement alone are deeply troubling,” he said.

His remarks come as NEOM faces growing internal and external challenges. Last week, the acting CEO of the project initiated a “comprehensive review” of NEOM’s operations, including an evaluation of the Sustainability Advisory Committee’s future role.

According to Wuebbles, this review has already resulted in the entire operation being “slowed down by six to 12 months.”

In addition to environmental issues, NEOM has been mired in controversies over the past several years, including allegations of executive mismanagement, labor abuse, funding shortfalls, and chronic delays.

An internal audit leaked earlier this year projected that the project may take over 50 years to complete—far beyond the original target of 2030.

Wuebbles also expressed frustration over a lack of transparency, stating that academic studies commissioned by NEOM in response to his environmental concerns were never shared with him. “It’s difficult to provide meaningful guidance when you’re kept out of the loop on the findings,” he added.

Despite these warnings, Saudi officials remain committed to NEOM, touting it as a model for sustainable urban development. But with one of its own sustainability advisors sounding the alarm, the project’s environmental credentials are now under increasing scrutiny.

As NEOM moves forward, the tension between innovation and environmental responsibility continues to mount, raising fundamental questions about the future of mega-infrastructure projects in fragile ecosystems.