Why (and how) I’m taking the two tonne challenge

We talk a lot about companies, policies, countries reducing emissions to limit the impact we have on climate change. Yet we often overlook the obvious challenge that a 50% decrease in line with Paris Agreement targets means that by 2030 we all need to be emitting less than 2.5 tonnes of CO2 - total - in our own lives.

I’ve been involved in a lot of systemic campaigning, including getting coal out of schools and loopholes in the ETS closed. But when I thought of a new climate goal for the new year (in January 2024), it seemed like it was time to turn my mind to the elephant in the room: my personal actions.

Like all good New Years’ resolutions, I have to admit I didn’t fully think it through. Could I divide my carbon footprint by six in one year? Two tonnes is less than one Aucklander emits while driving around town for one year. Am I a sucker for a challenge? Possibly. Was it rational? Definitely not. But once I had the idea, I was curious - what would it look like to truly do enough personally?

It has meant some very awkward conversations, bemused acquaintances, a few funny moments, and a fun and healthy lifestyle! I’m here to tell you about my exploration into a two tonne lifestyle this year over the next few weeks, and suggest policies which would make our nation thrive while living a two tonne life.

Why two tonnes? Living in line with a 1.5 degree world

The Paris Agreement, the international treaty on climate change, is aiming to keep the increase in average global temperature to “well below” 2°C pre-industrial levels, while striving for 1.5°C.

For this to happen, the ‘annual carbon budget’ per person will need to be roughly 2.3 tonnes of CO2 per person per year by 2030, down from 4.6 tonnes on average globally today. It’s also worth noting the report didn’t cover other greenhouse gases.

Two tonnes would be the maximum amount that the average person can emit, in order for us to stay within this temperature limit. Over 50% of the world currently live under two tonnes, but many people emit over 10 - 1000 times more CO2.

Per Capita Greenhouse Gas Emissions, 2022, from Our World in Data

Didn’t we debunk the concept of reducing carbon footprints?

While yes, the fossil gas industry did fund popularising the concept of the carbon footprint to blame people for their emissions (and avoid taking responsibility), some of us are doing the same by saying that systemic change is the only thing that will have an impact. 

Both groups who believe there is only one solution are wrong. The question isn’t individual or systemic change. It’s both, and fast!

The reality is - we need both individual and systemic change - and both as urgently as we can. And each has a snowball effect on the other, encouraging further action, once taken. 

Together they form a virtuous cycle increasing the pace of both systemic and individual change.

A great example of societal + political changes fuelling each other from Hannah Ritchie’s blog, Sustainability by numbers. Feel free to imagine this was about public transport or cycle lanes instead of EVs!

Studies have shown the immense ripple effect one person can have in their actions. And if policy change doesn’t feel fast enough - what better way to feel impact than changing what you can control? 

I’m not suggesting that individual actions will solve climate change alone. To get emissions to zero we have to transform every part of our society, our economy, our industries & infrastructure. This challenge is a real-life experiment to see what life at two tonnes would look like, and to discover the systemic changes we need to make the dream of a low-carbon life a reality. 

Is two tonnes even hard?

Two tonnes is not an unambitious challenge. NZ’s per capita (per person) emissions are the fourth highest in the OECD. Our average emissions in NZ are 16.5 tonnes per person per year. Two tonnes is how much CO2 pollution is created from just one flight from Auckland to London, the emissions from an average Aucklander’s commutes, or from a meat-eater eating one red meat meal a day. 

How appropriate: a dinosaur graph to show us who burns the most dinosaurs. IMAGE: Oxfam.

Which lifestyle changes actually matter?

After doing a lot of research, I found this nerdy spreadsheet from the UK Scientists for Global Responsibility, which showed how to take a ‘two tonne pledge’. It turns out there are ten key things to get right. Because NZ has more renewable energy than the UK, I adapted these guidelines to get my lifestyle in Auckland to 2 tonnes. (Come back for the next installment to see if I am on track!)

Goal #1: Air Travel: No flying on planes. Hello to trains!

Goal #2: Food: 100% plant-based, minimise food waste. Fun and yum!

Goal #3: Land travel: No car ownership, no cruises, walk and cycle everywhere. This allows for up to 5,000km by train, 5,000km by bus and short distance trains, 950km by car travel, carpooling or renting, and minimise ferries. To give you an idea, Auckland to Wellington is 650km by car, 680km by train.

I’ve got rid of the car, and got big panniers for the eBike. Not sure I can only do four return trips to Welly though - will have to squeeze something to hit this target!

Goal #4: Electricity Usage: use less energy, only up to 3500 kWh per person per year. Who knows this?! Will have to do some power bill research.

Goal #5: Energy: buy 100% renewable. This is tricky. I don’t believe in RECs, so will have to hope the NZ grid is renewable enough to have emissions under the target.

Goal #6: Small Home: 33m2 per person max. Easy - I’ve got two flatmates anyway!

Goal #7: Stuff: Buy second-hand, almost no new stuff. Yikes. Fun challenge!

Goal #8: Pets: No meat-eating pets. Done - I don’t have any non-meat-eating pets either

Goal #9: Finances: minimise savings invested in high-carbon stocks, like fossil fuel companies. I’ve signed up to Pathfinder via InvestNow.

Goal #10: Holidays: maximum 7 weeks in self-catering or eco-hotels. Sure – also, I wish I had 7 weeks of leave for holidays!

In Part Two: How it went, and what were the biggest challenges - and delights - along the way. 

Have you ever tried a challenge like this? Get in touch if so! 

Want to join the 2025 Two Tonne Challenge? Sign up here!

Emily Mabin Sutton is an emerging director, on the board of Consumer NZ, Clean Planet, and Cool-Safe Trust. She is also general manager of Climate Club, a climate non-profit that runs climate workshops as well as Climate Fresks - a climate game played by 1.9 million people worldwide.

Read the next instalment in Emily's two tonne challenge: Finding the recipe for a low carbon diet