The declaration of a climate emergency tells the people of New Zealand, and the international community, that this is who we are and this is where we are going, writes James Renwick, a climate scientist and member of the NZ Climate Commission.

Last week Jacinda Ardern tabled in parliament a motion to declare a climate emergency in parliament. What does it mean for us in real terms? And was it a good idea?

For all sorts of reasons, it was absolutely a good idea. To reduce global warming to a level that is even somewhat manageable, emissions have to reduce rapidly, starting right now. Getting to zero emissions by 2050, after decades of steady growth, means a massive turnaround in how the New Zealand economy, and the world economy, are powered. Every month that goes by without some kind of reduction in emissions is a month that makes the task harder.

This is a challenge the world community has to meet. If we don’t, the consequences will be catastrophic, in terms of displacement of populations, crop failures and food shortages, and conflict over resources. Defence forces all over the world are aware that climate change is a “threat multiplier” and could trigger conflict in any number of regions. Climate change is the biggest problem we face, and we must pull out all the stops.

A declaration in itself, however, does not change anything. There must be action to follow it up. New Zealand has taken some criticism lately for being big on the talk and small on the walk, and fair enough. Our emissions show no sign of decreasing yet, and carbon dioxide emissions from transport (from us driving our cars, mostly) have increased massively over the past 30 years. There are plenty of steps we could have and have not been taking. But the government has hardly been idle the past few years. The passing of the Zero Carbon Act, the setting up of the Climate Change Commission, and the passing of legislation to require the financial sector to report on climate risks (the first country to do this) are all positive policy steps towards the framework we need for reducing emissions. The next step is to see those reductions starting to happen.

Action does indeed seem to be on the table now. The announcement that the public service will be carbon neutral by 2025 is a great example of the kind of action we need to see. If the public service vehicle fleet was to become completely electrified by 2025, that would be a game-changer for the EV market in New Zealand and would really kick-start the move to a fully electrified vehicle fleet across the whole country. In the same way, if all the office space occupied by the public service was to be well-insulated, energy-efficient, renewably powered and heated, that would change the landscape for the commercial building sector across the country. Just leading the way has a lot of power in itself, and once the country starts moving in the right direction, I expect that action and innovation will take off.

If the whole country can become renewably powered by 2050, including electricity, transport, freight, industry, manufacturing, it would be a wonderful achievement, a demonstration that it can be done. What needs to happen alongside that effort is to work with other countries to help them on the same journey and to inspire action in other parts of the world. Just as New Zealand is seen as a leader in tackling terrorism and online extremism after the Christchurch mosque attacks, we can also be leaders in the green revolution and the transition to a renewably-powered economy that every country must make.

There will be costs up front, to electrify the vehicle fleet, invest in public transport, build more renewable electricity infrastructure, and all the things we need to do to get us where we need to go. But it is not all about cost. There are many opportunities as well, to innovate around renewable electricity, urban design, integrated transport systems, community action – innovations we can market around the world. Being a leader on climate change action will create a myriad of new jobs and is bound to be good for our economy as investors are attracted to share in our success.

The coming years must be ones of transformation for all of us. Starting next year, the Climate Change Commission will be providing advice to government to help New Zealand get to zero carbon as soon as we can. Declaring a climate emergency puts a stake in the ground, telling the people of New Zealand, and the international community, that this is who we are and this is where we are going.