Fuel walking and cycling with low carbon diets, researchers say

June 11, 2020

Walking and cycling have many benefits and help reduce greenhouse gas emissions, but researchers say we need to think about what people eat to fuel their walking and cycling.

In a paper published in the international journal, Scientific Reports, the researchers say people who shift from passive modes of transport, such as driving, to active modes, such as walking, will have higher energy needs, which could lead to an increase in food-production related emissions.

The study is understood to be the first international estimate of greenhouse gas emissions associated with the extra food intake required per kilometre travelled by active transport.

Lead researcher Dr Anja Mizdrak from the University of Otago, Wellington, says producing the food required to fuel walking and cycling does come at a cost.

"We have a conundrum - but a solvable one. To maximise the benefit on greenhouse gas emissions achieved by increasing active transport, we need to also address dietary patterns. Emissions associated with active transport will be lower if walking and cycling are powered by low-carbon dietary options."

The research estimates that the additional energy expenditure required to travel one kilometre ranged from 48 to 76 kilocalories for walking and 25 to 40 kilocalories for cycling.

"If this energy is compensated with extra food intake, travelling an additional kilometre in the most economically developed countries could result in an increase in greenhouse gas emissions by 0.26 kilograms CO2-equivalents per kilometre for walking and 0.14 kilograms CO2-equivalents per kilometre for cycling."

Dr Mizdrak says there is a significant difference in greenhouse gas emissions related to food production between the most and the least economically developed nations.

"There is a wide variability in emissions required to compensate for walking and cycling between countries, representing an almost five-fold difference between the most and the least economically developed countries."

Dr Mizdrak says active transport has many advantages including more pleasant urban living, reduced air pollution, and a reduction in chronic diseases like cancer and heart disease.

"But to maximise the effect on greenhouse gas emissions achieved by increasing active transport, we need to address dietary patterns too. Emissions associated with active transport will be lower if walking and cycling are powered by low-carbon dietary options."

Dr Cristina Cleghorn, a nutrition researcher at the University of Otago, Wellington, and co-author of the research paper, says reducing meat consumption and shifting diets away from processed food and towards more vegetables, legumes, whole grains and fruits are likely to have health and environmental co-benefits.

"Given emissions associated with different food groups range widely - from 0.02 for legumes to 5.6 grams CO2-equivalents per kilocalorie for beef and lamb in one global study, consumers switching to foods with lower emissions could reduce overall dietary emissions by up to 80 per cent."

Dr Cleghorn says in high income countries, reductions in greenhouse gas emissions are largely proportional to the magnitude of meat and dairy reduction.

"In order to reduce greenhouse gas emissions we need to encourage changes in what we eat, as well as how we travel."
The research paper, 'Fuelling walking and cycling: human powered locomotion is associated with non-negligible greenhouse gas emissions' is published in Scientific Reports and can be read here: http://www.nature.com/articles/s41598-020-66170-y

University of Otago

Related Greenhouse Gas Emissions Articles from Brightsurf:

Climate change: Ending greenhouse gas emissions may not stop global warming
Even if human-induced greenhouse gas emissions can be reduced to zero, global temperatures may continue to rise for centuries afterwards, according to a simulation of the global climate between 1850 and 2500 published in Scientific Reports.

Climate-friendly Cooling Could Cut Years of Greenhouse Gas Emissions and Save US$ Trillions: UN
Energy-efficient cooling with climate-friendly refrigerants could avoid up to 460 billion tonnes of greenhouse gas equivalent being added to the atmosphere through 2060 - roughly equal to eight years of global emissions at 2018 levels.

Forests can be risky climate investments to offset greenhouse gas emissions
Given the tremendous ability of forests to absorb carbon dioxide from the atmosphere, some governments are counting on planted forests as offsets for greenhouse gas emissions -- a sort of climate investment.

Switching from general to regional anaesthesia may cut greenhouse gas emissions
Switching from general to regional anaesthesia may help cut greenhouse emissions and ultimately help reduce global warming, indicates a real life example at one US hospital over the course of a year, and reported in the journal Regional Anesthesia & Pain Medicine.

Women generate lower travel-related greenhouse gas emissions, NZ study finds
Women use more diverse modes of travel and generate lower greenhouse gas emissions than men, despite men being more than twice as likely to travel by bike, a New Zealand study has found.

Great potential in regulating plant greenhouse gas emissions
New discoveries on the regulation of plant emissions of isoprenoids can help in fighting climate change - and can become key to the production of valuable green chemicals.

Cable bacteria can drastically reduce greenhouse gas emissions from rice cultivation
The rice fields account for five percent of global emissions of the greenhouse gas methane, which is 25 times stronger than CO2.

Sugar ants' preference for pee may reduce greenhouse gas emissions
An unlikely penchant for pee is putting a common sugar ant on the map, as new research from the University of South Australia shows their taste for urine could play a role in reducing greenhouse gases.

Seeking better guidelines for inventorying greenhouse gas emissions
Governments around the world are striving to hit reduction targets using Intergovernmental Panel on Climate Change (IPCC) guidelines to limit global warming.

Emissions of potent greenhouse gas have grown, contradicting reports of huge reductions
Despite reports that global emissions of the potent greenhouse gas were almost eliminated in 2017, an international team of scientists, led by the University of Bristol, has found atmospheric levels growing at record values.

Read More: Greenhouse Gas Emissions News and Greenhouse Gas Emissions Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.