These emissions might be regarded as one of the elephants in the emissions reduction room, put in the too-hard basket internationally for too long.
Those who have been concerned at the environmental impact of cruise ships, proposals such as the international airport at Tarras, and air travel rising rather than reducing, will be pleased this issue is finally receiving some attention.
While New Zealand has yet to decide what it might do, other major economies including the United Kingdom, the European Union and the United States are moving on this.
Even so, the reductions likely to be possible are not expected to be enough to reach goals of net zero emissions by 2050 due to the practical limitations of the technology expected to be available, the commission says.
In New Zealand, the commission describes emissions caused by traffic to and from the country as significant and growing.
A 2019 estimate based on emissions from fuel taken on board by ships and planes refuelling here found it amounted to about 9% of the country’s total net greenhouse gas emissions that year.
The commission says we rank sixth in the world for highest international aviation emissions per person, based on refuelling occurring within the country, and 15th for most flights taken per person.
Our distance from other major economies means our international shipping and aviation emissions will be higher than for other countries to move the same amount of people or goods.
We have challenges not faced by many other countries because we cannot reduce our international emissions by switching to electric trucks, cars or rail.
New Zealand has the potential to produce alternative fuels, but their cost and supply are problematic.
Increasing their use could increase the price of international shipping and aviation which could reduce the use of this transport, impacting the country’s tourism and export sectors and making it harder for people to connect with people in other countries, the commission says.
Even if the New Zealand government decided to do nothing in this area, big business may well put pressure on.
Customers and companies, including brands such as Nestle increasingly have been seeking supply chains which have reduced greenhouse gases.
While applying New Zealand’s Emissions Trading Scheme to international aviation could face legal challenges, the possibility of doing this for international shipping is less likely to encounter this problem, the commission suggests.
The EU already includes international shipping in its Emissions Trading System, and several ports around the world adopt variable port charges, where better environmentally performing ships pay lower port fees.
The commission suggests the government could reduce demand for international aviation and cruise ships by changing how it markets New Zealand overseas, to focus on attracting high-spending tourists rather than concentrating on volume.
However, this could pose problems with some international air service agreements, which would need to be renegotiated and could also affect New Zealanders’ visa access to other countries.
Limiting airport expansion is another way of reducing possible growth.
The commission points out a reduction in international shipping caused by New Zealanders buying fewer overseas goods, or buying local instead, might impact revenue for shipping lines and businesses abroad but would not have significant negative domestic impacts.
New Zealanders choosing to limit their overseas travel would mean people who needed to travel could still do so.
Both actions could benefit the economy, it says.
Whether these are messages all New Zealanders are keen to hear is another matter.
Submissions on the commission’s consultation close at the end of this month. It will advise the government on the issue by the end of the year.
