"As stated in the IPCC special report on the impacts of global warming of 1.5C, by lowering our target half a degree from 2C to 1.5C, we can significantly decrease the impact of climate change," said the coalition member and SkyCity Entertainment Group boss, Graeme Stephens.
"The coalition's new pledge shows that we are ambitious about reducing emissions with the intention of educating our people, suppliers, customers and the wider public along the way.
"From small businesses to large, every action on climate change counts and collectively our actions can be mighty."
So far, 90 per cent of the businesses were measuring their emissions, 71 per cent were publicly reporting them, more than half have set a public emissions reduction target, and 60 per cent were working with suppliers to reduce their emissions.
Twenty-four signatories also reported reducing their emissions over the past year by a combined 569,000 tonnes of CO2 - or the equivalent of taking 264,000 cars off the road.
However, 21 members reported emissions trending upwards, which was put down to factors like organisations re-setting their baseline emissions profile, and business growth.
As well as accounting for 60 per cent of New Zealand's gross emissions, the coalition employed more than 170,000 people, and represented nearly one third of private sector GDP.
Climate Change Minister James Shaw, who, along with Prime Minister Jacinda Ardern is meeting coalition representatives today, praised the efforts.
"To my knowledge, no other country in the world has a business network for climate action that even comes close to the level of coverage across the economy, or as a portion of national emissions, that the Climate Leaders Coalition has," Shaw said.
"If these companies can reduce their emissions to live within the 1.5C threshold, then New Zealand as a whole should be able to achieve our collective goal outlined in the Zero Carbon Bill."
James Young-Drew, of youth-led climate action group Generation Zero, said it was heartening to see many of New Zealand's biggest emitters recognise the importance of limiting global warming to no more than 1.5C.
"But making pledges is not the same thing as cutting carbon pollution," he said.
"Emissions from 15 of the businesses in the Coalition are currently trending upwards. Unless they take real and urgent action, these businesses risk losing their social license to operate."
The coalition's first anniversary comes as coalition member Meridian Energy released New Zealand's first corporate report disclosing risks to its business resulting from climate change.
Prepared in accordance with guidance from the Taskforce on Climate-related Financial Disclosures (TCFD), the report laid out the physical risks the company faced from a rise in global temperature, as well as the impacts of transitioning to a low carbon future.
Climate change had urgent implications for companies and investors, and the time had come for businesses to be open and honest about the risks they will face, Meridian chief financial officer Mike Roan said.
"Globally, markets and investors have woken up to climate risk," he said.
"There's a growing movement to reconsider investments in companies and sectors who are heavily exposed, whether that's from sea level changes, industry disruption, the uptake of new technology or public policies and legislation."
By the numbers
90% of Coalition members were now measuring emissions
71% were publicly reporting emissions
55% had set a public emissions reduction target consistent with keeping within 2C of warming
60% had worked with suppliers to reduce emissions
