GENEVA — The World Health Organization appealed Thursday for $1.5 billion for emergency operations this year, warning that conflict, climate change, epidemics and displacement had converged to create an “unprecedented global health crisis.” The U.N. health agency estimated that health crises would leave 305 million people in need of urgent humanitarian assistance this year. “WHO is seeking $1.5 billion to support our lifesaving work for the emergencies we know about and to react swiftly to new crises,” WHO chief Tedros Adhanom Ghebreyesus said as he launched the appeal. The agency’s emergency request, which was for the same amount as last