A Pacific climate leader is warning the region's lowest-lying island states will be under water before countries hit their carbon zero targets, because the world's biggest emitters don't keep their promises.

New Zealand's Climate Change Commission chair, Dr Rod Carr, told Nine to Noon the science shows countries need to go beyond their pledges, and urgent action was needed.

RNZ Pacific's Koroi Hawkins spoke to the Director-General of the Pacific Regional Environment Programme Kosi Latu who said the agreement at COP26 was alarming.