Caritas New Zealand is calling for urgent international funding to help Pacific islands struggling with the effects of climate change.
In a new report, Small Yet Strong - Voices from Oceania on the Environment, the Catholic aid agency said some communities are having to build walls of sticks, stones and shells to hold back rising seas.
Caritas director, Julianne Hickey, said action is needed now to reduce carbon emissions and to help vulnerable communities to cope.
"At United Nations level we certainly need for there to be a commitment from the countries that are causing the environmental challenges for the people in the Pacific.
"But we also need to make sure the finance for climate change actually gets to those communities around the Pacific because at this stage we're not seeing on the ground much evidence of that."
The report talks to Pacific communities about how they are affected by environmental changes not of their own making, and what solutions they want.
Caritas Tonga's programme manager, Amelia Ma'afu, said climate change is a daily challenge for many communities in Tonga.
"From inundation of land to saltwater intrusion directly our drinking water supply, our ground water levels. Sea spray that affects yield size of our major food crops. Erosion of our coastlines, destruction of coastal communities.
Food security, the capacity of our families to feed themselves."
Ms Ma'afu said developed countries drag out talks on cutting carbon emissions because they see climate change as something far away.
But the Caritas report makes clear that Pacific people are dealing with it right now.
"The sea is destroying our homes, it's destroying our livelihoods. We are sinking. And that's the reality that we want to portray in this document. And we want recognition for this and we want justice for this."
Ms Hickey said it was a surprise to discover the extent of environmental changes affecting people right across the Pacific.
"Rising sea levels and water, issues with their food supply and food security, challenges with fishing, concerns over mining and new things like deep sea mining, and problems with things that have happened in the past like nuclear testing."
She said it makes daily life more difficult and unpredictable.
"Whether it's where they get their food from or the water that they drink, or cyclones and El Nino events, it's just more that they have to cope with."
Ms Hickey said New Zealand should use its voice at the UN to get more international climate change funding to the Pacific communities that most need it.