That would mean reduced car use, upgraded public transport, further development of cycling and walking networks, and more businesses and people acquiring electric vehicles.
Continued efforts would be needed to improve energy efficiency within buildings through switching fuels, upgrading insulation and use of more efficient devices such as heat pumps.
In Dunedin, most coal, lpg and diesel was used in non-residential settings, primarily to generate heat, a report for the Dunedin City Council pointed out.
A draft zero-carbon plan is to be discussed by councillors tomorrow and it presents achievement of 2030 targets as "possible" if much collective work is done, and quickly.
The council declared a climate emergency in 2019 and aims to have Dunedin absorbing as much carbon as it emits by 2030.
Cutting biogenic methane is on a separate track, out to 2050, and modelling suggests the city might do better than what a 2030 interim target would require of it.
Net-zero emissions excluding biogenic methane could be achieved with an overall 40% reduction in all other greenhouse gases and with a 64% increase in sequestration (from plants absorbing carbon) against 2018-19 levels, modelling showed.
The council’s report showed challenges for transport loomed large.
"To achieve 2030 targets, Ōtepoti Dunedin needs to reduce emissions from transport by at least 42% below 2018-19 levels."
Emissions from air travel would need to be cut in half.
Marine emissions would need a 40% reduction and those from the cruise sector by at least 40%.
On-road transport generated 56% of transport sector emissions and cars generated almost half of the on-road emissions, the report said.
It commented residents who drove to work or education sites identified safer roads and more and safer cycleways as the interventions most likely to lead them to cycle.
"Provision of cycleway networks is also a very cost-effective way of reducing transport emissions."
The council is working on a plan for walking and cycling.
Some Dunedin aspirations rely on the government achieving targets.
The government had a goal of a 100% renewable national electricity grid by 2030 and, if it happened, this would significantly reduce the city’s emissions, the report said.
Significant changes were needed in the way homes, schools, organisations and businesses were designed, heated and powered, it said.
