Monday, October 4th, 2010
The NY Times is running a story, Military Orders Less Dependence on Fossil Fuels, that evaluates the American military’s role in green energy innovation:
Even as Congress has struggled unsuccessfully to pass an energy bill and many states have put renewable energy on hold because of the recession, the military this year has pushed rapidly forward. After a decade of waging wars in remote corners of the globe where fuel is not readily available, senior commanders have come to see overdependence on fossil fuel as a big liability, and renewable technologies — which have become more reliable and less expensive over the past few years — as providing a potential answer. These new types of renewable energy now account for only a small percentage of the power used by the armed forces, but military leaders plan to rapidly expand their use over the next decade.
“There are a lot of profound reasons for doing this, but for us at the core it’s practical,” said Ray Mabus, the Navy secretary and a former ambassador to Saudi Arabia, who has said he wants 50 percent of the power for the Navy and Marines to come from renewable energy sources by 2020. That figure includes energy for bases as well as fuel for cars and ships.
While setting national energy policy requires Congressional debates, military leaders can simply order the adoption of renewable energy. And the military has the buying power to create products and markets. That, in turn, may make renewable energy more practical and affordable for everyday uses, experts say.
Last year, the Navy introduced its first hybrid vessel, a Wasp class amphibious assault ship called the U.S.S. Makin Island, which at speeds under 10 knots runs on electricity rather than on fossil fuel, a shift resulting in greater efficiency that saved 900,000 gallons of fuel on its maiden voyage from Mississippi to San Diego, compared with a conventional ship its size, the Navy said.
The Air Force will have its entire fleet certified to fly on biofuels by 2011 and has already flown test flights using a 50-50 mix of plant-based biofuel and jet fuel; the Navy took its first delivery of fuel made from algae this summer. Biofuels can in theory be produced wherever the raw materials, like plants, are available, and could ultimately be made near battlefields.
Photo credit: Shortbread1015DT
Friday, September 24th, 2010
Mike Berners-Lee and Duncan Clark at The Guardian have a recent post in the series examining the carbon footprints of daily life activities. Their post asks how much carbon emissions results from the direct and indirect activities of building a car.
The carbon footprint of making a car is immensely complex. Ores have to be dug out of the ground and the metals extracted. These have to be turned into parts. Other components have to be brought together: rubber tyres, plastic dashboards, paint, and so on. All of this involves transporting things around the world. The whole lot then has to be assembled, and every stage in the process requires energy. The companies that make cars have offices and other infrastructure with their own carbon footprints, which we need to somehow allocate proportionately to the cars that are made.
….The best we can do is use so-called input-output analysis to break up the known total emissions of the world or a country into different industries and sectors, in the process taking account of how each industry consumes the goods and services of all the others. If we do this, and then divide by the total emissions of the auto industry by the total amount of money spent on new cars, we reach a footprint of 720kg CO2e per £1000 spent.
This is only a guideline figure, of course, as some cars may be more efficiently produced than others of the same price. But it’s a reasonable ballpark estimate, and it suggests that cars have much bigger footprints than is traditionally believed. Producing a medium-sized new car costing £24,000 may generate more than 17 tonnes of CO2e – almost as much as three years’ worth of gas and electricity in the typical UK home.
17 (metric) tons is 17,000 kg or about 37,400 pounds. The U.S. EPA estimates that the average passenger vehicle in the U.S. emits 5-5.5 metric tons CO2e per year, assuming 12,000 miles driven.
If you do the math, this means the embodied CO2e emissions to make a car is about 3-3.5 years worth of tailpipe emissions from driving. Assuming that most people own their cars for longer than three years, this figure doesn’t jive with what the authors claim:
The upshot is that – despite common claims to contrary – the embodied emissions of a car typically rival the exhaust pipe emissions over its entire lifetime. Indeed, for each mile driven, the emissions from the manufacture of a top-of-the-range Land Rover Discovery that ends up being scrapped after 100,000 miles may be as much as four times higher than the tailpipe emissions of a Citroen C1.
If people held onto their cars for 10 years (assuming 120,000 miles), tailpipe emissions would equal 50 metric tons of CO2e, and embodied emissions would be about 34% of tailpipe emissions. If people drove their cars for 20 years (assuming 240,000 miles), the exhaust emissions would rise to 100 metric tons CO2e, with embodied emissions dropping to 17% of tailpipe emissions.
While most folks generally agree with the notion of driving their vehicle into the ground (as my recently dead 16-yr-old truck illustrates), you’d have to be driving a Toyota Prius to get a lifetime tailpipe emission that equals the embodied emissions of building it (assuming that a Prius achieves three times the mpg of a typical car, which would drop CO2e tailpipe emissions from 5 to 1.7 metric tons CO2e per year, making a 10-year total tailpipe emission of 17 metric tons reasonable).
Thus, if you drive an average car for 10 years, your lifetime tailpipe emissions (50 metric tons) will be a lot larger than the embodied emissions to build the car (17 metric tons) (for a total emission of 67 metric tons). If you drive a hyper-efficient vehicle for 10 years, tailpipe and embodied emissions may be comparable (17 metric tons each, 34 metric tons total). This means you could buy a new Prius every three years, and the embodied emissions from all of these purchases plus tailpipe emissions would roughly equal a normal car driven for 10 years.
This raises an important question: What matters here? If the goal is to reduce total emissions, the best thing is to buy a car with a very high fuel efficiency and drive it for its full life, as the above examples illustrate.
Photo credit: atomicshark
Sunday, September 5th, 2010
Mitigating climate warming is going to require a dramatic decrease in carbon emission from the transportation sector, through a combination of driving less, using public transportation, and, eventually, switching to electric cars powered by a renewable grid.
There are many urban centers with outstanding public transportation options, but let’s face it— It’s often more difficult to find alternatives to driving in smaller towns and suburbs.
Brunswick, Maine (home to Bowdoin College) is no different than most small towns (population 25,000). Transportation is one of the largest sources of carbon emissions, and the physical dislocation of residential areas, shopping centers, supermarkets, and hospitals makes it difficult to avoid automobile use. And roads around here are definitely not bike friendly!
This is starting to change as a result of collaborations across institutions from the local to federal levels.
The town just added a new program called Brunswick Explorer, with a fleet of hybrid electric buses that are wheelchair and bike accessible. The route takes the buses from major residential areas (especially those serving the elderly) to our local supermarkets, hospitals, and shopping malls.
With the extension of the Amtrak Downeaster from Portland to Brunswick in 2012, folks will also be able to travel to Portland and Boston easily by train, especially during rush hour and winter when travel by roads is either a hassle or dangerous.
The Explorer and Downeaster are certainly no silver bullets, but they accomplish a few important goals:
These are small steps, indeed, but they have the ingredients to be successful: alternatives to personal vehicle use that are both cheap and convenient, with substantial community buy in.
Photo courtesy of Bowdoin College
Monday, March 8th, 2010
It’s been easy for citizens of the developed, industrialized world to criticize China and India over their rapidly growing greenhouse gas emissions. This was one of the major reasons why the Kyoto Protocol was never ratified in the United States.
As many have pointed out, however, there are several flaws with this argument:
Until today, there haven’t been very good estimates of these kinds of shadow emissions.
In the Early Edition of the Proceedings of the National Academy of Sciences, Steven Davies and Ken Caldeira examine how much CO2 is embodied in the import and export of goods.1
Their results are interesting (excerpts below—If you can get a copy of the article, check out figures 1 and 2; they are terrific visuals for this information. Alas, copyrights don’t allow me to post them):
Consumption-based accounting reveals that substantial CO2 emissions are traded internationally and therefore not included in traditional production-based national emissions inventories. The net effect of trade is the export of emissions from China and other emerging markets to consumers in the United States, Japan, and Western Europe. In the large economies of Western Europe, net imported emissions are 20–50% of consumption emissions; the net imported emissions fall to 17.8% and 10.8% in Japan and the United States, respectively. In contrast, net exports represent 22.5% of emissions produced in China. Thus, to the extent that constraints on emissions in developing countries are the major impediment to effective international climate policy, allocating responsibility for some portion of these emissions to final consumers elsewhere may represent an opportunity for compromise.
1Steven J. Davis and Ken Caldeira (2010). Consumption-based accounting of CO2 emissions PNAS : 10.1073/pnas.0906974107
Tuesday, March 2nd, 2010
The issue of land use change is a complex, with many factors being important historically, such as
Their results were interesting (excerpts):
They provide a simplified snapshot of how development changes with history and geography (for a more-thorough yet readable treatment of land use in the U.S., check out Crabgrass Frontier by Kenneth Jackson):
The process of development plays out differently in cities with different socioeconomic histories. Moreover, cultural differences exist among and within many U.S. cities, leading to varying spatial patterns of development. However, a general historical pattern exists. In many U.S. cities, an urban core existed in the decades or centuries prior to the widespread use of the automobile, and these neighborhoods have high population density and small amounts of developed area per capita. The surrounding suburban and exurban areas, created predominately after WWII, contain residents living at lower population density and consume more land per capita. There are substantial economic links between these two zones, and in contemporary U.S. cities commuting occurs in both directions. Northeast U.S. cities that developed before the automobile typically follow this narrative. Many have a relatively dense urban core, but have adopted zoning policies that ensure contemporary suburban settlements occur at lower density. While they remain dense compared to other U.S. cities, they are getting less dense over time, as proportionally more of the population is in suburban areas. The declining manufacturing cities of the Rust Belt and the Southern Appalachians are an extreme example of this spreading out of population.
Southeastern U.S. cities, excluding Florida, are often newer and have less of a legacy of a dense urban core. They do not appear to be getting markedly denser, and the relatively fast population growth of these cities implies that their total impact on natural habitat in coming decades will be large. In contrast to the Southeast, Western cities appear to be getting denser, including those that do not have a historical legacy of a dense urban core such as Phoenix. These Western cities are often still growing quickly and consuming a great deal of land, but contemporary development is making these cities denser than they were previously. Many of these Western cities have a strong conservation culture, and the degree of conservation funding and reform-minded zoning correlates with how much denser they are getting. However, it should be noted that contemporary development in Western cities is still well below the densities found in the dense urban core of Northeastern U.S. cities, posing problems for designing effective public transit systems.
1McDonald, R., Forman, R., & Kareiva, P. (2010). Open Space Loss and Land Inequality in United States’ Cities, 1990–2000 PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009509
Monday, January 11th, 2010
Growing sustainability from the bottom-up in any community is challenging. Here’s one way that the Golden Gophers are working on it:
Getting 10,000 people at the University of Minnesota to agree on any one subject is difficult. But 10,000 students, faculty and staff do agree on one thing: saving energy on campus is important.
The U of M has just met its goal of collecting 10,000 energy conservation pledges from students, faculty and staff as part of the It All Adds Up campus energy conservation campaign. The 10,000 pledge marked was topped early Thursday after a flurry of pledges came in response to a university-wide e-mail from President Robert Bruininks asking the Twin Cities Campus to take the pledge.
The university rolled out It All Adds Up last spring in an effort to increase campus awareness about how each person at the U could play a part in saving energy. The energy conservation pledge asks individuals to take seemingly small actions – like turning off lights or powering down computers at the end of the day – with the understanding that if each member of the 80,000 person campus community did those small actions, it would all add up.
Here’s another bottom-up approach, and the FL Gators get a gold star for doing it with one of the hardest behavioral modifications—driving:
The second annual One Less Car challenge was a success, with nearly 1,000 people participating. More than 100 teams represented students, faculty, and staff from departments and units across campus. Together, One Less Car participants avoided over 260,000 miles of driving during the challenge. Through alternative transportation commutes, such as busing, biking, and walking, approximately 246,370 pounds of carbon dioxide were kept from entering the atmosphere.
The teams that used alternative transportation for the most miles were: The Office for Student Financial Affairs, The Florida Museum of Natural History, and The College of Dentistry. Final prizes were awarded to the teams with the highest average points per member: Extreme Backroads, Los Tamales Calientes, Radical Gainesville, Geography, and No glass on the bike lanes. Individuals also earned prizes for logging the most trips and avoiding the most miles of driving. Final prizes included: lunch from Satchel’s Pizza, bike tune-ups, Hippodrome Tickets, Gator Dining meal coupons, and tickets to the Butterfly exhibit at the Florida Museum of Natural History.
For more information: AASHE bulletin 1/1/10
Wednesday, December 9th, 2009
The NY Times is running an op-ed, Catch of the Freezer, by a few ecological economists who were interested in learning whether it’s more sustainable to eat fresh or frozen seafood.
Focusing on salmon as a case study, they suggest that it does matter. Eat frozen when you can to reduce carbon emissions:
When it comes to salmon, the questions of organic versus conventional and wild versus farmed matter less than whether the fish is frozen or fresh. In many cases, fresh salmon has about twice the environmental impact as frozen salmon.
The reason: Most salmon consumers live far from where the fish was caught or farmed, and the majority of salmon fillets they buy are fresh and shipped by air, which is the world’s most carbon-intensive form of travel. Flying fillets from Alaska, British Columbia, Norway, Scotland or Chile so that 24 hours later they can be served “fresh” in New York adds an enormous climate burden, one that swamps the potential benefits of organic farming or sustainable fishing.
There are a lot of other important questions about sustainable seafood, including harvest rates, the industrialization and carbon intensity of the fishing process, genetic modification of farmed species, and organic pollutant loads in wild vs. farmed fish. In terms of transportation and climate warming, this article offers a useful point of view, but I think their statement dismissing the importance of organic and wild vs. farmed is a bit parochial to a discussion of seafood sustainability writ large. It depends on what part of sustainability—warming, human health, fish stocks, genetic alteration—matters most to you.
Monday, November 9th, 2009
Let’s take a look at five innovative and exciting ideas from Stanford University, City College of New York, Western Michigan University, UC-Davis, and the University of Arizona…
Sunday, November 8th, 2009
Transportation is one of the largest parts of most people’s carbon footprint. Unfortunately, it’s also one of the hardest behaviors to change.
A new study1,2 by Daniel Feiler and Jack Soll in this week’s Online First edition of Climatic Change, “A blind spot in driving decisions: how neglecting costs puts us in overdrive” suggests that if we accounted for the costs of driving, this could be the incentive we need to reduce mileage (another example of framing climate change in terms of personal finance).
Our driving costs are surprisingly high…