Shugaban kasa Muhammadu Buhari ya sake neman goyon bayan kasashen duniya kan wasu manyan matsaloli kamar ta'addanci, tayar da kayar baya, kaurar jama'a, da sauyin yanayi, yana mai sake jaddada cewa kalubalen da ke ci gaba na haifar da babbar barazana ga rayuwar bil Adam.