The Ministry for the Environment is projecting New Zealand's greenhouse gas emissions will increase faster than it previously predicted.
Last year, the Ministry for the Environment projected total carbon emissions would be just over 70 million tonnes by 2040.
In its latest projection, it is predicting emissions rising to 90 million tonnes by that year.
In its commentary on the forecast, the ministry gives no reason why the outcome looks worse.
The Green Party says the latest projections show that New Zealand is on the wrong track when it comes to dealing with climate change.
Climate change spokesperson Kennedy Graham says changes the Government made to the emissions trading scheme are responsible for the worsening outlook.
"You've got this extraordinary blow-out in emissions going up to anything close to 100 million tonnes by 2025 to 2030. It's a policy failure of monumental proportions by this Government."
Dr Graham says the scheme needs to be strengthened to help reduce emissions.