Up to seven per cent of the country's greenhouse gas emissions come from just one per cent of New Zealand's soil, according to an updated estimate.
Drained peat bogs, rain-fed wetlands that were drained so the land could be farmed, are used mainly for dairy farming in Waikato, Southland and elsewhere.
The emissions are around twice what was previously calculated, and there's no plan in place to stop it.
Climate Correspondent Eloise Gibson reports.
