Ian Roberts: Slim chances for a fat planet
28 Apr, 08 | by Ian Roberts
Last week the geopolitics of the biofuel debacle looked something like this. On the left both geographically and politically, we had Evo Morales, President of the very poor and increasingly hungry Bolivia, pleading “la vida primero los autos segundos” (life first, cars second), exhorting the wealthy world to stop burning food in their cars.
On the right, we had Gordon Brown, fresh out of his food summit, calling for more agricultural research, free trade and food aid for the starving.
Apart from calling for better roads so that poor farmers can “sell their products in our markets” Brown, made no reference to transport as a protagonist in the struggle for energy between people and cars. Morales, who as a youth witnessed a cocoa farmer being doused in petrol and burned alive, understands how transportation fuel use by the rich equals suffering for the poor. Brown’s was a serious oversight.
Car use and food prices were linked long before policies on biofuels. Car use in rich countries increases the price of food because thanks to agricultural research, oil is now an essential agricultural input and rising car use drives up the oil price. In its daily communion with the sun, the earth’s surface is blessed with only about 200 watts of radiant energy per square metre. Plants raise their leaves to receive this energy and after sipping carbon dioxide from the atmosphere, carry out photosynthesis to make the food that sustains all life. For centuries, incoming solar energy set a limit on the amount of food energy that could be harvested from a given amount of land. But the discovery of seemingly limitless supplies of oil changed everything.
From the 1940s onwards, fossil fuel based fertilisers, pesticides, irrigation and mechanisation dramatically increased food yields. Modern agriculture became the use of land to turn petroleum into food. The transportation sector is almost entirely dependent on oil and without billions of barrels of this precious black sludge to lubricate them, the words roads and the global economy would grind to a halt. Petrol tanks and stomachs were competing to be filled long before biofuels were proposed to tackle climate change.
But the links between transport, food and the environment go much deeper. Try this out: car use causes obesity, obesity increases car use and rising obesity increases food consumption and worsens global warming. If that sounds like a vicious circle with dire implictions for global food security and the environment then you are on the right track. Take a non-obese seventy kilogram man of stable weight. He starts to drive rather than walk the 500 metres to the office every because he thinks buses are for losers. In just over a year he will have gained a kilogram of fat due to his use of fossil fuel energy rather than food energy for transport. The gradual accumulation of fat will continue. His increasingly heavy body will become a disincentive to physical activity and due to movement inertia he will be loathe to walk or cycle anywhere, choosing instead to use the car for even short journeys. The energy imbalance that causes obesity is small but self perpetuating. As he gets fatter back pain, arthritis and shortness of breath will add to his movement discomfort. Low self esteem from body dissatisfaction will lead to comfort eating and he will start drinking more of that deceptively energy dense anaesthetic called alcohol. The physics of human movement quickly lock the transportation system into a downward spiral of increasing vehicle use and obesity. More traffic means more dangerous kinetic energy on our streets which keeps the podgy children indoors and the cyclist scared.
That was the vicious circle part now here is the crunch. Obesity increases food demand and prices because obese populations eat more food calories. Despite the claims by fatties to be small eaters, the physics of personal energy expenditure means that an obese person will consume substantially more food than a lean person. The human body is a vehicle designed for personal transportation and whether idling or moving a fat body is a gas (food) guzzler. The global demand for food is increasing because rich people are getting fatter and as well as eating more meat, which requires greater land use than is used in growing grains and vegetables, they are simply eating more. Because food production accounts for about 20% of greenhouse gas emissions, more than from transport or industry, the carbon footprint of an obese population is a chubby one. Greater food consumption means more organic waste which produces methane when it decomposes. As the obesity pandemic develops populations eat more and pollute more.
Only one of the twenty experts brought together in Gordon Brown’s food summit had a remit for transportation energy use and if more road building was their only contribution, then their claim to expertise must be challenged. It may be too late to escape the downward spiral of increasing body mass and vehicle use but we must act now and decisively. The current EU policy on biofuels was a sop to a car industry opposed to increasing vehicle energy efficiency but making cars more fuel efficient is not the whole answer. There is no place for private passenger cars in towns and cities. Walking, cycling and public transport is a lifeline to urban sustainability that will not empty the stomachs of the poor and will deliver huge health gains for rich and poor alike. With a quarter of UK adults now obese the prospects of a renaissance in active transport are not looking good. Brown acknowledged that while short term measures are needed to deal with immediate hardships, the structural causes of increasing food prices must be addressed. Transport policy is food policy and walking and cycling is the future for transport. The chances are slim for an obese planet.
Ian Roberts
Professor of Public Health
London School of Hygiene and Tropical Medicine
Thanks Ian for spelling out the nexus between fuel and food so clearly. I hadn’t quite realised how blatant it was until your piece. Maybe I won’t buy that SUV after all….
Take care, Anna
Anna Donald
April 29th, 2008 at 3:58 am
Yes that is a good idea do not purchase that suv
Leon Avalos
April 29th, 2008 at 4:32 pm
Did anybody read this (tongue-in-cheek) response by Lawrence Ulrich “Check the Spare : Does Driving Make you Fat?” http://en.autos.sympatico.msn.ca/guides_and_advice/article.aspx?cp-documentid=5581166
I found the viewpoint from the Car-and-Driver columnist most entertaining but also sadly on point. The selfish preoccupation Western society has with its own convenience and efficiency is costing us everything - our environment, our health, and ultimately our future.
Gabrielle Gaedecke
April 29th, 2008 at 7:07 pm
We need to take serious actions to eliminate inhibitors of active life styles in our communities
We certainly need to congratulate Dr. Ian Robert for his thought provoking note. With the growing trend in childhood obesity, the issue of a decline in our children’s level of physical activity is now at the forefront of public health challenges. As there are many public health benefits to an active life style the rights of pedestrians and cyclists to use roadways safely, both as a means of transport and as a leisure activity, need to be safeguarded in order to increase the pleasure and likeness of walking in our neighborhoods. All road users deserve better and safer road travel.
To promote walking and cycling as an active mode of transportation it is critical to first identify the perceived and real barriers, second, recognize effective strategies and then further develop them to surmount the problems that hinder walking and cycling. An increase in activity of 30 minutes per day has been proposed as an adequate amount of exercise which would curtail the effects of a higher calorie diet. This roughly equates to the amount of time a child would normally spent commuting to and from school. The health benefits of active commuting have been proven in the adult population; one study found that there was a 40% reduction in all cause mortality for men and women who cycle to work. Walking and cycling are two forms of physical activity that meet the metabolic criteria for achieving health benefits from exercise. The consultation document from the Health of the Nation physical activity taskforce concludes that activities of moderate intensity, such as brisk walking and cycling, offer the greatest potential of health gain for most of the population. Efforts to create safe and accessible routes for children to walk and bike to school will create a trickle down effect for people of all ages.
In 1969, approximately half of all schoolchildren walked or bicycled to or from school and 87% of those living within 1 mile of school used active modes of transportation to get there. By contrast, today fewer than 15% of children and adolescents use active modes of transportation. One recent study in the US explored the question of why children don’t walk to school more often. Parents reported multiple barriers as follows: long distances (55%), traffic danger (40%), weather (24%), crime (18%), and school policy (7%). Similarly, a recent study in the UK showed that 85% of parents were worried about traffic danger on the journey to school. Traffic dangers, perceived and real, are discouraging parents from allowing children to walk and cycle to school, a trend seen across the globe: in the UK less than half of primary school children walk to school (18) and 50% are driven less than a mile to school, in India children are discouraged from walking or cycling to school due to increased vehicle danger.
Ediriweera Desapriya
April 29th, 2008 at 7:32 pm
Yet another attack on cars and those that actually derive pleasure from motoring. Now the motorist can drive around secure in the knowledge that they will become obese as their gas guzzler gently warms the planet causing ecological mayhem. If they are not satisfied with this then they should take heart from the thought of causing global poverty and destitution whilst killing a few pedesterians and cyclists by driving far too fast and recklessly. Perhaps the internal combustion engine should be banned and we can happily skip back to the dark ages. The only problem with that plan would be the urgent need for a new scapegoat for all the worlds ills!
Peter Savill
April 29th, 2008 at 7:50 pm
Congratulations to Dr Roberts for his bold comments and to the London Shool of Hygience for employing someone with a ‘big picture’ approach to health. It is about time we had some more intense health input into what John Snow showed in the mid 19th Century - that the broader environment is intimately connected to human health - and increasingly more so in exponentially expanding economic system. With some more input like Professor Roberts’, we may also eventually be able to talk publically about the biggest elephant in the room - population control - without which all environmental action is ultimately overwhelmed.
Garry Egger
April 30th, 2008 at 12:05 am
Ian, good to read your thoughts on food and fuel. Maybe the cause is lost for some populations that have been down this path for a long time. But do low income countries have a fighting chance? It is painful though, to know that while most ‘poor’ people walk out of necessity, they are only helping to coserve fuel so the rich can burn even more. The links between food and fuel are not being often enough, and loud enough. And when the debates happen, they are accompanied by lavish, obcenely fat rich dinners. Olive
Olive Kobusingye
April 30th, 2008 at 8:17 am
what is with these attacks on cars man!!!
Leon Avalos
April 30th, 2008 at 3:13 pm
Bio-fuels may be derived from food products but they become a “food substitute”.
Are “Ersatz”. Not digested .
These enter the body as TRANS-FATS and probably never leave it.
Don’t they remain as obese botties, big titties, etc.?
Better by far to go back to Granny’s recipes using Pork Lard, Beef Dripping, Butter and so on. They will get metabolised.
Got enzymes for them, see? You needn’t eat a lot of them.
Those “Veg. Oils”, “Veg. Solids” appear in most Ice Creams and packaged foods in the big supermarkets.
Be warned.
GEORGE CALDWELL
May 10th, 2008 at 1:25 pm
excellent Dr Roberts. your analysis is far more sharp than of transport scholars. i am always impressed by your writing. moreover, it has no jargon.
best
vidyadhar date
vidyadhar date
May 30th, 2008 at 11:47 am
I’m not entirely convinced of the link between cars and obesity. US per capita calorie intake did not start to rise until the 1980’s (http://www.ers.usda.gov/publications/FoodReview/DEC2002/frvol25i3a.pdf), at least a decade or two after widespread car use came to the US. It would seem generally true that the less work people do, the less they need to eat. Accordingly cars should reduce food intake, if indeed (and it’s a big if) using a car tends to result in doing less physical work. If on the other hand we take the line that doing less work results in consuming more food, then surely the car is a minor factor. The complete transition of many economies to office based service jobs away from heavy manufacturing is surely far more important. The person who cycles 20 minutes to their office is surely far more indolent than the person who drives 20 minutes to their job stacking shelves in a supermarket.
Yet, it does not seem to be the case that office workers are all obese, and manual workers are lean.
I think people are obese because eating is fun, and the cost of food calories as a percentage of income has been falling. And I think people drive cars because it’s useful, and the cost of cars as a percentage of income has been falling.
The notion that people eat more because they do less requires more rigorous analysis, I think.
Jon Peterson
June 9th, 2008 at 5:23 pm