Climate change action priorities, simplified version: reduce green house gases, protect habitats, protect wildlife and protect humans. For this post, I’m going to focus on protecting humans – operationalized as reducing the extra deaths caused by climate change.

A huge factor in reducing climate-change related deaths is economic development. Specifically, as GDP increases, mortality rates decrease. Mean death rates fall by 15% for every 10% increase in GDP. And we’re not just talking about old people getting a couple extra years: on average, a 10% increase in income means a 5% fall in infant mortality.

So, proposals designed to reduce GHGs that also reduce economic development need to look at the trade-offs involved. Of course we need to reduce GHGs – but if the means are so drastic that GDPs are greatly reduced and, consequently, millions die, we should be upfront about that. Put that trade-off on the table. Don’t pretend it doesn’t exist.

“Climate change could kill more than 500,000 adults in 2050 worldwide due to changes in diets and bodyweight from reduced crop productivity, according to new estimates. The research is the strongest evidence yet that climate change could have damaging consequences for food production and health worldwide.”

– Marco Springmann, Daniel Mason-D’Croz, Sherman Robinson, Tara Garnett, H Charles J Godfray, Douglas Gollin, Mike Rayner, Paola Ballon, Peter Scarborough. Global and regional health effects of future food production under climate change: a modelling study. The Lancet, March 2, 2016 DOI: 10.1016/S0140-6736(15)01156-3

The authors predict that, compared to a future without climate change, climate-change related reduction in fruit and vegetable intake could lead to an extra 534,000 deaths, mostly in China and India. This is the worst-case of the four scenarios used by the authors. Their message is we’ve got to get more serious about climate change.

The challenge is to find solutions that don’t lead to more lives lost than saved. For instance, policies that decrease global GDP in any significant way would increase mortality rates. Ditto for policies that make it hard for small farmers to diversify into a broader range of farm and nonfarm activities. And policies that make it harder to adopt GM crops will reduce food security, calorie consumption, and dietary quality for billions.

Additional References:

Salvador Pérez-Moreno, María C. Blanco-Arana, Elena Bárcena-Martín. (2016) Economic Cycles and Child Mortality: A Cross-National Study of the Least Developed Counties. . Economics & Human Biology.

Peter Hazell. Five Big Questions about Five Hundred Million Small Farms. Paper presented at the IFAD Conference on New Directions for Smallholder Agriculture 24-25 January, 2011

Qaim M, Kouser S (2013) Genetically Modified Crops and Food Security. PLoS ONE 8(6): e64879. doi:10.1371/journal.pone.0064879

This chart is from the USDA Economic Research Service.  It shows that US farmers consider the environmental effects of agricultural production, e.g., soil erosion and the loss of sediment, nutrients, and pesticides to water, and have adopted conservation practices to mitigate these effects.  Use of such practices has increased substantially over the past 20 years. Farmers will continue to adopt conservation practices when it’s affordable.  Luckily, government programs promote adoption rates by helping defray costs. There is reason to hope.

“The human mind comprises evolved intuitions that shape and constrain cultural preferences. In the case of GMOs, folk biology, religious intuitions, and emotions such as disgust leave the mind readily seduced by representations of GMOs as abnormal or toxic.”

– Blancke, S., F. Van Breusegem, G. De Jaeger, J. Braeckman, and M. Van Montagu. 2015. Fatal attraction: the intuitive appeal of GMO opposition. Trends in Plant Science 20:414–418.

“We have reviewed the scientific literature [1783 studies] on GE crop safety for the last 10 years that catches the scientific consensus matured since GE plants became widely cultivated worldwide, and we can conclude that the scientific research conducted so far has not detected any significant hazard directly connected with the use of GM crops.”

– Nicolia,A.,Manzo,A.,Veronesi,F.,and Rosellini,D.(2014). An overview of the last 10 years of genetically engineered crop safety research. Critical Reviews in Biotechnology. 34, 77–88. doi:10.3109/07388551.2013.823595

“Golden Rice has not yet been approved in any country, including India. According to our calculations, the delay over the last 10 years has caused losses of at least 1,424,680 life years for India, ignoring indirect health costs of VAD [vitamin A deficiency].”

– Wesseler, J. and Zilberman, D. (2014) The economic power of the Golden Rice opposition. Environment and Development Economics 19, 724–742

“Overall, the review finds that currently commercialized GM crops have reduced the impacts of agriculture on biodiversity, through enhanced adoption of conservation tillage practices, reduction of insecticide use and use of more environmentally benign herbicides and increasing yields to alleviate pressure to convert additional land into agricultural use.”

Janet E. Carpenter (2011) Impact of GM crops on biodiversity, GM Crops, 2:1, 7-23

Bottom line: Widespread adoption of GM crops will save millions of lives and protect the environment. It will help us adapt to climate change by increasing the resilience of crops, while contributing to climate change mitigation by freeing up land for reforestation. Opposition to GMOs in general or as a matter of principle is irrational and based on deep-seated biases in the human psyche.

In a previous post, I calculate ground vehicle CO2 emissions using the following formula: number of miles driven per week * weeks in a year) / average vehicle fuel efficiency * pounds of CO2 emitted per gallon, which is about 20 pounds (go to http://www.firmgreen.com/faq_calculate.htm for explanation of formula). So, for instance: assuming we drive 20,000 miles a year and our vehicle gets an average of 35 miles a gallon, our annual emissions would be roughly: 20,000 miles/35 = 571 x 20 = 11,420 pounds of CO2 a year.

How does ground vehicle travel compare with air travel? It depends on how long the flight is (given that cruising emits less CO2 than take off and landing). Here’s one formula:

Short flight of 500 miles x .64 lbs/mile = 320 pounds of CO2 (640 pounds roundtrip)
Medium flight of 1600 miles x .44 lbs/mile = 704 pounds of CO2 (1408 pounds roundtrip)
Long flight of 3000 miles x .39 lbs/mile =1170 pounds of CO2 (2340 pounds roundtrip)

So one roundtrip flight across the US would be about 2000 pounds of CO2, or a bit over 1/5 of driving 20,000 a year at 35 mpg. Overseas travel puts us in a whole ‘nother league, emission-wise: 15,000+ miles round trip from San Francisco to Calcutta – or about 6 months of vehicle travel at the pretty good 35 mpg.

For perspective, when planning your travels…. and remember: the more stops, the more emissions.

Life cycle analysis is a “systematic approach of looking at a product’s complete life cycle, from raw materials to final disposal of the product. It offers a “cradle to grave” look at a product or process, considering environmental aspects and potential impacts.” (Life Cycle Analysis: A Step by Step Approach, 2009, Aida Sefic Williams). When comparing emissions of e-commerce versus traditional retail, getting a product to the consumer is just one part of the puzzle. There’s also what happens before delivery, especially inventory logistics and packaging.

I’m going to cut to the chase: e-commerce beats traditional retail hands-down. Here are a couple quotes. First from Life Cycle Comparison of Traditional Retail and E-commerce Logistics for Electronic Products: A Case Study of buy.com:

“Our results confirm prior findings that e-commerce delivery uses less primary energy and produces less CO2 emissions than traditional retailing. Considering retail and e-commerce logistics differences, the three largest contributors were customer transport, packaging, and last mile delivery. Customer transport encompassed approximately 65% of the traditional retail primary energy expenditures and CO2 equivalent emissions on average. For e-commerce, packaging and last mile delivery were responsible for approximately 22% and 32% of the e-commerce energy usage, respectively. Overall, e-commerce had about 30% lower energy consumption and CO2 emissions compared to traditional retail using calculated mean values.”

In the picture is worth a thousand words department:

And this from The Environmental Impact of Online Shopping: Nitty-gritty by Anna Argyridou, in which the author compares online and traditional book buying. Her conclusion:

“…The bottom line? Unless you’re walking or biking to the bookstore, buying a book online results in lower carbon emissions than purchasing it from a traditional bookstore. Light-duty delivery vehicles operated by companies like UPS and FedEx travel well-designed routes that serve multiple consumers in a minimum of trips, achieving fuel economy higher than that of a typical individual consumer driving alone to make the same purchase.”

So I say: buy online when possible. Yeah, there’s a certain community feeling of buying stuff at Mrs. Smith’s shop (though I’ve never been that sentimental about the shopping experience, which for me and many people has been more impersonal wandering of malls and superstores than sharing a moment with the neighborhood store clerk). If social bonding with acquaintances is what you’re looking for, there are alternatives, such as cafes, restaurants and YMCA classes – which you’d be better able to afford with the savings made possible through online shopping.

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For much of the last century, buying stuff has meant driving to a store, at least for most Americans most of the time. According to the federal government, “shopping and errands” accounted for 35.4% of all household vehicle travel in 1990 – more than double that of 1969. But the trend is reversing: in 2009, shopping and errands accounted for just 30.7% of household vehicle travel.

Other sources confirm that Americans are driving less to shop. The decline in leisure shopping is well-known. Less well-known is that Americans are taking fewer trips to the grocery store. Demographic change, revitalized urban centers and the “casualization of American life” all contribute to this trend. And then there’s the increasing popularity of online shopping.

Leaving aside a certain nostalgia for the in-person shopping experience, and the dilemma of what to do with all that empty real estate, and looking just at the net effect on CO2 emissions, I think the ascendancy of online shopping is a good thing.

With online shopping, vehicles, usually trucks, deliver purchases to many homes on a single route. On average, home delivery results in fewer emissions per item than get-it-yourself shopping.

The energy inefficiency of get-it-yourself shopping is partly offset when we buy a bunch of items in one trip. But it takes a whole lot of buying to neutralize the home delivery advantage: when customers buy fewer than 24 items per shopping trip, CO 2 emissions per item are still likely to be lower under home delivery.

Of course, some of us are able to walk, bike, or take public transportation to go shopping. But for most of us, and for most products, these are not reliable options. Plus, the larger stores have lower prices, and they tend to be in areas that favor cars, or at least would be time consuming and a big hassle to get to by other means. And that’s really important for people with limited time and budgets.

For instance, in one recent USDA study, the closest grocery store was an average of 2.0 miles away from low-income households, but the store primarily used for grocery shopping was, on average, 3.4 miles away. Value and not proximity predicted where these households shopped. A whopping 95% of those surveyed used a car to do grocery shopping.

Delivery trucks may also be more fuel-efficient than many cars, especially SUVs. UPS, for example, has invested millions of dollars in alternative fuel technologies, and its fleet includes thousands of low-emission, hydraulic, hydrogen fuel cell and electric vehicles. Fed Ex has a large hybrid fleet and is testing all-electric vehicles.

Delivery is only part of the emissions picture though. The environmental edge in home delivery may be lost, or at least minimized, by higher emissions at an earlier state of the product life cycle. For instance, e-commerce packaging practices – with all that shrink-wrapping, padding and boxing of individual items – is hardly a model of energy efficiency.

Next up we’ll zoom out and look at the entire product life cycle to better gauge the net emissions impact of online shopping.

The last post included ideas on reducing emissions in freight transport. This and the next few posts will be about reducing the carbon footprint of personal vehicle travel. How much CO2 do cars actually emit? Here’s one formula, provided by http://www.firmgreen.com/faq_calculate.htm:

Emissions = (number of miles driven per week * weeks in a year) / average vehicle fuel efficiency * pounds of CO2 emitted per gallon, which is about 20 pounds.

How might this translate to actual emissions in one’s own household? For an idea, let’s assume our vehicle gets an average of 35 miles a gallon:

15,000 miles/35 = 429 x 20 = 8580 pounds of CO2 a year
20,000 miles/35 = 571 x 20 = 11,420 pounds of CO2 a year

Plug in your own car mileage and annual miles and you get the picture. We’re talking about a lot of CO2. Next up: exploring ways to reduce that footprint, starting with shopping behavior.

Reducing emissions from transportation is mostly a matter of reducing demand for transported goods, improving fuel efficiency and improving transportation efficiency – that is, moving the same amount of cargo (e.g., people and things) with fewer trips and fewer vehicles.

We’re going to start with freight transportation. This includes shipping, rail, and road transport. Important parameters determining the exact value of the emission factor for each mode of transport include:

– The load factor (payload) i.e. CO2 emissions per transport unit.
– The energy efficiency of the vehicle, train or vessel.
– The carbon intensity of the energy source i.e. the amount of CO2 emitted per unit of energy consumed.

As a rule, transport by water is the most energy efficient mode of freight transport, followed by rail, then big rigs, then smaller vehicles.

Here are some recommendations to reduce CO2 emissions in freight transport:

1. Switch from road to rail transport when possible.
2. Switch from overland to water transport (e.g., ferries, barges and ships) when possible.
3. Manufacturers share deliveries to minimize transport distance to customers, e.g., manufacturers near each other share deliveries to customers near each other. The idea here is to minimize empty cargo space and maximize load factors.
4. Maximize direct deliveries from manufacturer to end user, minimizing transport to and from intermediaries in the supply chain.
5. Minimize empty running (trucks with no load) by better efficiency/logistics and shared use of fleets. You don’t want trucks going hundreds or thousands of miles and then making return trips with nothing.
6. Increase vehicle payloads. The more units of cargo a truck transports, the less CO2 emissions per unit.

That last recommendation means bigger trucks emit less CO2 per unit than smaller ones, other stuff being relatively equal. Sure, big trucks are less fuel efficient per mile – but that’s much less important than fuel efficiency per unit transported. This also means that local is not always better if local means more small trucks and more deliveries per truck (with smaller and smaller loads)and  a lot of empty running on the way home.