Despite the absences, the politics of catastrophe and climate inaction toward Earth's impaired health await the assembly's annual gathering of world leaders next week in New York.
'Extremely high water stress' afflicts 83% of the population in the Middle East and North Africa and 74% in South Asia.
Syrian President Bashar Assad, formerly ostracized by most Arab nations, was warmly readmitted to the Arab League.
The figures show an 'intolerable' loss of life amid more reports of government-led rescue delays and obstacles to NGOs' search and rescue efforts, the U.N. migration agency said.
The number of refugees, internally displaced people and asylum-seekers rose by 2.3 million from 2017. And over the past two decades, the number has doubled.
Disasters and conflicts drove nations atop a list of places adding to the 28 million people newly displaced at home.