Negotiators gathered for the U.N. climate talks in Poland are getting down to the nitty-gritty part of the two-week meeting.

Diplomats from almost 200 countries began holding a series of technical talks Tuesday aimed at finalizing the rules that define the 2015 Paris accord on curbing global warming.

Decisions on crunch issues are expected to be left to ministers when they return to the southern Polish city of Katowice next week.

U.N. Secretary-General Antonio Guterres made a dramatic appeal to governments Monday to confront the threat of unchecked climate change.

Scientists say manmade emissions of greenhouses gases must be reduced to net zero by 2050 to stop catastrophic warming this century.

(AP)