Negotiators toiled Tuesday to break a deadlock at UN climate talks after G20 leaders acknowledged the need for trillions of dollars for poorer nations but left key sticking points unresolved. Negotiators toiled Tuesday to break a deadlock at UN climate talks after G20 leaders acknowledged the need for trillions of dollars for poorer nations but left key sticking points unresolved. Environment Phys.org – latest science and technology news stories