New Zealand promised its public sector would become carbon neutral by 2025 as it declared a climate emergency on Wednesday, a symbolic move that critics said needed to be backed with greater actions to reduce emissions.

Prime Minister Jacinda Ardern (above) said the climate emergency declaration was based on the Intergovernmental Panel on Climate Change's findings.

It stated that to avoid more than a 1.5 degree Celsius rise in global warming, emissions would need to fall by...