Could you live on a One Tonne Diet?

It has long been a point of contention: do individual actions make a difference, or are they pointless diversions? The question always is whether individual actions are like recycling, pointless diversions to make us feel better while the big corporations keep pumping out more CO2?

One new study, 1.5-Degree Lifestyles: Targets and options for reducing lifestyle carbon footprints, from the Institute for Global Environmental Strategies and Aalto University, argues that in fact, our individual actions could add up to make a big difference. In fact, they suggest that we have no choice: "Changes in consumption patterns and dominant lifestyles are a critical and integral part of the solutions package to address climate change."

The report proposes globally unified per capita targets for the carbon footprint from household consumption for the years 2030, 2040 and 2050. It estimates current average carbon footprints of Finland and Japan, as well as Brazil, India, and China, focusing on the comparison of the level of physical consumption in order to be both comparable to global targets and compatible with household-level solutions. It also identifies potential options for reducing lifestyle carbon footprints on the basis of the literature and assesses the impact of such options in Finnish and Japanese contexts.

In studying the lifestyles in a number of countries, the study finds that there are "hotspots" where individual changes would make the biggest difference:

Focusing efforts to change lifestyles in relation to these areas would yield the most benefits: meat and dairy consumption, fossil-fuel based energy, car use and air travel. The three domains these footprints occur in – nutrition, housing, and mobility – tend to have the largest impact (approximately 75%) on total lifestyle carbon footprints.

Well, yes, what we eat, where we live and how we get around just about defines our entire lives; that makes sense. But where do you start? How much do we have to cut?

The first analysis in the study determined the per capita carbon emission target to meet the IPPC goal of keeping temperature rise to 1.5°C. The targets are "are based on a simplified calculation using population projections and house- hold footprint share." Today, the average Finn emits 10.4 tonnes, the average Japanese 7.6, Chinese, 4.2. For 2030, the targets are between 3.2 and 2.5 tonnes per person. (A Metric tonne, at 1000 kg, is not too far off from an American Ton.)

3.2 tonnes isn't much. With Finns, food alone is 1.75 T, and it's mainly because of the meat. Housing is also big at .62 T, mostly for heating. But in the developed countries, the biggest contributor is mobility, fully a quarter of their footprint. According to the study, the Finns drive a lot (11,200 km per year) but that's only 7,000 miles, nothing by North American standards. They also fly a lot.

Bringing up the rear are consumer goods and shopping for clothing, goods, services, adding up to 1.3 T for Finns, 1.03 for Japanese.

So what can you do? As the study notes, "The reductions required towards 2030 and 2050 are not incremental but drastic." Let's concentrate on the Finns, as their data most closely resemble European and North American conditions.

© IEGS/ Aalto University

In nutrition, the single biggest reduction in CO2 impact can be achieved by going vegan, with vegetarian not far behind.

© IGES/ Aalto University

In housing, going all renewable is best, although renting out a guest room is surprisingly close to getting heat pumps or improving energy efficiency.

© IGES/ Aalto University

In Mobility, getting rid of the car is off the scale, the most important thing you can do. (I don't know why regular bikes are not listed and why vehicle improvements are higher than getting an e-bike; the data seem weird to me here.)

In every case, a significant modal shift is far more significant than just reductions in use or increases in efficiency. We have to change our ways.

The options with potentially high impact include: car-free private travel and commuting, electric and hybrid cars, vehicle fuel efficiency improvement, ride sharing, living closer to workplaces and in smaller living spaces, renewable grid electricity and off-grid energy, heat pumps for temperature control, vegetarian and vegan diets, and substitution of dairy products and red meat.

Some are taking this very seriously; Rosalind Readhead, whose earlier manifesto for dealing with climate change was impressive, is going to try to live a one ton lifestyle, where she tries to live a lifestyle that emits less than a tonne per year. That is going to be really tough; as she notes, a single round-trip flight to Paris emits a tonne of CO2. The average Brit emits 11.7 tonnes, the average American 21.

Living a one tonne lifestyle sounds almost impossible; try living in a closet, walking or cycling everywhere, eating local beans and never buying anything. Perhaps that is an exaggeration, but it is a very tough target.

It reminds me of the 100 Mile Diet that was such a big deal a few years ago. Alisa Smith and J.B. MacKinnon tried to eat nothing but local food and found it a true challenge. They started at the wrong time of year (there was almost nothing in April) and lost 15 pounds in six weeks. Rosalind has scoped this out and is starting in September.

She is really on to something here. The 100 mile diet became a big deal, a successful book and even a TV show. Perhaps more people will climb on this bandwagon.

But perhaps it's time for all of us to fire up all those carbon footprint calculators and start taking this very seriously. Because if this study is correct, it means that our individual actions can add up and make a very big difference. The one tonne diet looks tough, but it's a terrific aspirational target.