The Intergovernmental Panel on Climate Change (IPCC), the United Nations body charged with assessing the science related to climate change, has released its latest report outlining the affects global warming has on nature and people around the world. Eric Chu, assistant professor in human ecology and co-director of the Climate Adaptation Research Center at UC Davis, served as a lead author for chapter six of the IPCC Working Group 2 report, which outlines the impacts and risks to cities, human settlements and infrastructure.

“More than half of people around the world live in cities,” Chu said. “By 2050 the projection is that two thirds of people will be living in cities, and that really drives home the message that cities are hot spots of climate risks. Figuring out how cities can adapt to climate impacts is key.”

Regions around the world are experiencing climate-driven hazards like sea level rise, extreme heat, drought, intense precipitation and wildfires, and according to the report, people and ecosystems least able to cope with those threats are among the hardest hit. The report outlines that if global warming exceeds a 1.5-degree Celsius threshold in the coming decades, then the world will face additional severe risks, some of which will be irreversible.

“One of the key messages from this report is the need for more actions to get a handle on greenhouse gas emissions and get a handle on how to manage and deal with the growing and multiplying climate risks that we’re seeing around the world,” Chu said. “Social equity and justice must be central to how we decide to respond to climate impacts. Frontline communities, many of whom have historically been excluded in decision making, must be part of the solution.”

This report is the second installment of the IPCC’s Sixth Assessment Report, which will be completed this year. More than 270 scientists from 67 countries spent the past four years compiling this latest report. While it’s not policy prescriptive, Chu says the report indicates that a coordinated global action plan is needed now to help people adapt to increasing climate risks.

“By 2040 or 2050 we need some transformative ideas to prevent the worst of the climate impacts,” Chu said.