Archive for the ‘technology’ Category
« Older Entries |The hidden global CO2 emissions of consumerism
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:
- The per-capita carbon emissions in China and India remain much lower (1/4 and 1/16, respectively) compared to the U.S..
- Perhaps more importantly, some of the carbon emission in these countries is caused by the production of export goods to fuel consumer demand in wealthy nations. Thus, we are responsible for “shadow carbon emissions” that get attributed to developing nations.
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):
- Approximately 6.2 gigatonnes (Gt) of CO2, 23% of all CO2 emissions from fossil-fuel burning, were emitted during the production of goods that were ultimately consumed in a different country.
- Emissions imported to the United States exceed those of any other country or region, primarily embodied in machinery (91 Mt), electronics (77 Mt), motor vehicles and parts (75 Mt), chemical, rubber, and plastic products (52 Mt), unclassified manufactured products (52 Mt), wearing apparel (42 Mt), and intermediate goods (654 Mt).
- These imports are offset by considerable US exports of transport services (49 Mt CO2), machinery (42 Mt), electronics (26 Mt), chemical, rubber, and plastics products (25 Mt), motor vehicles (22 Mt), and intermediate goods (263 Mt).
- [G]oods imported to Western Europe and Japan embody much more CO2 per US$ than do their exports, reflecting the import of energy-intensive products from elsewhere.
- The carbon intensity of imports to China, Russia, India, and the Middle East is consistently far less than that of their exports.
- China is by far the largest net exporter of emissions, followed by Russia, the Middle East, South Africa, Ukraine, and India and, to a lesser extent, Southeast Asia, Eastern Europe, and areas of South America.
- The primary net importers of emissions are the United States, Japan, the United Kingdom, Germany, France, and Italy. Although the overall mass of emissions is much less, the other countries of Western Europe are all net importers, as are New Zealand, Mexico, Singapore, and many areas of Africa and South America. Similarly, Canada, Australia, Indonesia, the Czech Republic, and Egypt are among the countries whose net exports of emissions are small.
- On a per-capita basis, net imports of emissions to the United States, Japan, and countries in Western Europe are disproportionately large, with each individual consumer associated with 2.4–10.3 tons of CO2 emitted elsewhere.
Their conclusion:
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
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Photo Credit: http://www.flickr.com/photos/deks/ / CC BY-NC 2.0
Tags: China, India
Posted in behavior, climate change science, climate economics, energy, nature and culture, technology, transportation | 1 Comment »
Cell phones and your health
Saturday, February 27th, 2010
Environmental Working Group (EWG) has updated their information on cell phone radiation and potential health risks.
As I alluded to in a previous post, conducting human health risk analyses for things like cell phone radiation exposure is difficult because it’s hard to determine how much exposure is too much, and it takes years to see what health effects might show up.
The research below suggests that links between cell phone radiation and health are now becoming evident.
And with more than 4 billion cell phone users worldwide (2/3 of the human population), we are unintentionally conducting one of the largest epidemiological studies of all time.
Learn more from EWG:
- Risks and research—executive summary
- Risks and research—full report (pdf)
- How much radiation does your cell phone emit?
- How to reduce radiation exposure
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Photo credit: http://www.flickr.com/photos/gibbons/ / CC BY-ND 2.0
Tags: consumer
Posted in health, risk analysis, technology | 1 Comment »
Energy breakthrough? Have fuel cells for the masses finally arrived?
Monday, February 22nd, 2010
Huff Post is running a story on a recent 60 Minutes piece about a new kind of fuel cell—the “Bloom Box” —that is already powering companies like Google, Fed Ex, and EBay (click on the link for video of this story).
It runs on natural gas, and two of these little boxes (about the size of a shoe box combined) could conceivably power your entire home.
Estimated cost: $3,000 for off-the-grid electricity.
It will be interesting to see if these are commercially viable and what else Silicon Valley has in store over the next five years. Along with electric cars, which roll into showrooms in a matter of months, we are on the cusp of some pretty big technology transformations.
Update: An educated guess from one of my colleagues, Andy Price, in the energy business:
I hope I am wrong, but the Bloom Box looks like it suffers from the same problem that all fuel cell companies are suffering from: their systems are really expensive per KW.
If Ebay paid $700,000 to $800,000 per unit for 5 units, as was suggested in the story, this would be $3.5 to $4 million. If they saved the stated $100,000 in 9 months this would be a 26 to 30 year payback – and with a fuel cell using natural gas you still need a natural gas pipe and have associated carbon emissions.
If Bloom can somehow deliver the dramatic cost reductions that they claim
this could start to look more attractive but until Bloom provides additional
details, it looks like more hype than substance. Many other well funded
companies including UTC, Honda and GE are working on similar technology and none have been able to deliver the big breakthrough. Yet.
Update 2: Wired comes to a similar conclusion–too pricey.
Tags: fuel cell
Posted in energy, solutions, sustainability, technology | No Comments »
Can we alter climate by installing white roofs?
Monday, January 11th, 2010
When reviewing the most popular words of 2009, I was surprised to see that “albedo” didn’t crack the top 5—Tweet, Obama, H1N1, Stimulus, and Vampire. I bet you were equally shocked.
Albedo is a simple concept—the reflectivity of a landscape—but it’s hugely important in understanding how the surface of the Earth impacts climate. As we saw in a recent post, things like thawing sea ice, northward advancing treeline, and asphalt paving all darken landscapes, causing more solar radiation to be absorbed and temperatures to climb—one of the reasons for the so-called urban heat island effect.
So what would happen if we were to install white roofs? In a forthcoming article1 in Geophysical Research Letters (subscription required), Keith Oleson and colleagues use biophysical models to address this.
Their answer: White roofs reflect more sunlight and cool buildings. Averaged over all urban areas in the world, the urban heat island effect declines by 33%, causing maximum and minimum daily temperatures to decrease by 0.6 and 0.3 degrees C, respectively.
At face value, this sounds great. But, there’s a potential hidden cost of cool buildings—heating. Interestingly, they found that white roofs caused space heating to increase more than air conditioner use declined, suggesting that energy use might actually increase with white roofs!
1Oleson, K. et al. (in press) The effects of white roofs on urban temperature in a global climate model. Geophysical Research Letters.
Related post: New ideas about how changing vegetation at high latitudes can cause climate warming to accelerate
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Photo credit: http://www.flickr.com/photos/calliope/ / CC BY 2.0
Tags: albedo
Posted in behavior, climate adaptation, climate change science, energy, solutions, sustainability, technology | No Comments »
The promise and perils of algae-based biofuels
Monday, December 28th, 2009
In a forthcoming article1 in Trends in Ecology and Evolution, Val Smith and colleagues describe why biofuels produced from algae have many benefits:
- The current production of biodiesel (~2 billion gallons in 2006) is far lower than annual consumption of diesel fuel (44 billion gallons per year). Simply put, biodiesel crops can’t keep pace with demand. We would have to grow significantly more biofuel crops, which would affect land use by reducing the acreage of food crops or natural habitats.
- Algae fats (lipids) can serve as the feedstocks for many types of fuels, including aviation fuel, which would be a major benefit because airline travel is a huge part of most people’s carbon footprints. Algae fuels are potentially carbon neutral. Making air travel carbon neutral would be a game changer.
- Algae grow extremely fast—much faster than terrestrial plants (which are made into biodiesel or ethanol). They lack anatomical parts like roots, flowers, and woody stems that don’t help plants photosynthesize (making them more productive than plants).
- One of the most amazing statistics in this paper is how much less land it would take to make algae based fuels compared to terrestrial plants because of the increased productivity of algae. To produce an amount of fuel equivalent to the global demand for oil, we would only need an area of land equivalent to 3-20% of current croplands. If we were to use biofuel plant crops instead, we would need about 2-8 times the amount of current global cropland. That’s so amazing I did a double take when I read it.
- Algae can be grown in tanks on lands that are marginally useful for crops so that we don’t have to sacrifice croplands.
- They can serve double-duty by removing excess nutrients from wastewater, thereby linking energy production and wastewater treatment.
- Algal production virtually eliminates the use of herbicides and insecticides and uses much less water than growing crops for fuels.
They also point out an interesting pitfall:
- Bioreactors containing algae are often unintentionally invaded by zooplankton that eat the algae. This can lead to predator-prey-type cycles in algae biomass, which is not good when you want to maximize algal biomass production.
- The solution? Add fish that eat the zooplankton. This would cause “top-down” pressure on the zooplankton, keeping their populations in check.
1Smith, V. et al (in press) The ecology of algal biodiesel production. Trends in Ecology and Evolution.
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Photo credit: http://www.flickr.com/photos/sandialabs/ / CC BY-NC-SA 2.0
Posted in biofuels, energy, solutions, sustainability, technology | 3 Comments »
If we switch to biofuels, how much do indirect greenhouse gas emissions matter?
Saturday, December 5th, 2009
In this week’s issue of Science, Jerry Melillo and colleagues investigate1 what kinds of impacts might arise from changing land use to grow more cellulosic biofuel crops. If you think about it, the switch to biofuels could have a big impact on greenhouse gas emissions—and not in a good way. For instance, clearing a forest or pastureland to grow a biofuel crop could cause a net release of carbon from the ecosystem, as plant growth changes, biomass is lost, and soil decomposition increases.
Using a model of the world economy coupled to a terrestrial ecosystem model, they considered two cases:
- Case 1: Natural lands (e.g., forests and pastures) are allowed to be converted to meet increasing biofuel demand.
- Case 2: Existing managed lands are managed even more intensely to generate biofuel demand.
What did they find?
Posted in biofuels, technology | No Comments »
In this week’s issue of Nature: What do radar, nuclear power, the Internet, and DNA have in common with technological innovation to decarbonize the economy?
Wednesday, December 2nd, 2009
Most of the focus these days is on how we can mitigate climate warming by achieving specific reductions targets like 20% by 2020 and 80% by 2050. Economists from McGill University, Isabel Galiana and Christopher Greene, are going to stir up debate in their latest paper1 in Nature by arguing that the current way of thinking about mitigating warming needs to be turned on its head.
Focusing on rapid emissions reductions, they say, may not be the best way to rapidly stabilize climate as cheaply as possible. They even go as far as to say that climate can be stabilized at a 2 degree C warming even if most of the carbon reductions don’t happen until after 2050.
What’s the basis for their argument? Technology-led approaches. Let’s see what this means…
Posted in climate economics, energy, sustainable development, technology | No Comments »
What are green energy investors waiting for?
Tuesday, November 17th, 2009
If Al Gore and others are correct that we already have available the kinds of renewable energy technology needed to decarbonize the economy, why is it taking so long? As we saw in an earlier post, part of the answer is carbon lock in resulting from our modern political economy.
Another way to examine this problem is to ask what motivates the investment community, particularly venture capitalists. What kinds of policies will entice these folks to plow $ billions into clean energy, and which ones will keep them on the sidelines?
In the current issue1,2 of Energy Policy, Mary Jean Buerer and Rolf Wuestenhagen examine this question by interviewing 60 senior fund managers around the world. They distinguished between policies that incentivized (1) “technology push”—forces like government funded research and development to increase the supply of renewable energy technology and (2) “technology pull”—things that increase the demand for green energy and the ability for businesses to provide it.
What did they find?
Posted in climate economics, energy, solutions, sustainability, technology | No Comments »
Are nanoparticles in consumer products increasing your cancer risk?
Tuesday, November 17th, 2009
The field of nanotechnology is exploding, and many materials, such as titanium (Ti), are being shrunk and used in consumer products like sun tan lotions, cosmetics, and toothpaste.
It has been traditionally thought that inert materials like Ti won’t cause health issues because they don’t react with molecules in our cells. New research from UCLA’s Jonsson Comprehensive Cancer Center published in Cancer Research suggests that this conventional wisdom may be flawed.
Ti appears to migrate throughout the body, causing DNA/chromosome breakage and inflammation (both of which are linked to cancer) and oxidative stress causing cell death. Rather than chemically reacting with molecules in cells, the high surface area of the tiny particles appears to cause cell molecules to change.
The manufacture of TiO2 nanoparticles is a huge industry, Schiestl said, with production at about two million tons per year. In addition to paint, cosmetics, sunscreen and vitamins, the nanoparticles can be found in toothpaste, food colorants, nutritional supplements and hundreds of other personal care products.
Once in the system, the TiO2 nanoparticles accumulate in different organs because the body has no way to eliminate them. And because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms.
Photo credit: http://www.flickr.com/photos/29487767@N02/ / CC BY-NC-SA 2.0
Posted in pollutants, risk analysis, technology, toxics | No Comments »
This week’s good ideas in campus sustainability: 11/9/09
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…
Posted in campus sustainability, environmental literacy, environmental science, higher education, sustainability, sustainable development, technology, transportation, urban | 1 Comment »
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