Archive for the ‘technology’ Category
« Older Entries | Newer Entries »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 »
Energy savings by peer pressure
Sunday, November 8th, 2009
Several interesting articles describe a new approach to saving energy—let people know how much they use relative to their neighbors:
- Keeping Up With The Joneses to Save Energy
- Utilities Turn Their Customers Green, With Envy
- Put Your Money Where Your B-Tush Is
- Nothing Like Some Friendly Neighborly Competition
When people see they are consuming way more energy than everyone else, there’s motivation to reduce.
Google’s PowerMeter (website, review, image below) is a great idea for helping visualize daily energy use so that folks who want to reduce electricity consumption have a better idea where to start. See also The Energy Detective for devices that work with Google’s PowerMeter.
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photo credit: http://www.flickr.com/photos/urbanjacksonville/ / CC BY-NC-SA 2.0
Posted in behavior, sustainability, technology | No Comments »
Why don’t people engage climate change? Problem 4: Political-economic context
Saturday, November 7th, 2009
Prerequisite posts:
- Why don’t people engage climate change? Overview
- Why don’t people engage climate change? Problem 1: Environmental Literacy
- Why don’t people engage climate change? Problem 2: Communication
- Why don’t people engage climate change? Problem 3: Personal perceptions, values, and behaviors.
People often disengage from environmental issues because of a sense of disenfranchisement: “What kind of difference can I make? Not much, so why bother? We need big changes and soon. The power to do this is controlled by politicians, who are influenced (financially and otherwise) by Big Business often intent on blocking change.”
In a series of provocative articles in Energy Policy1, Gregory Unruh posed two questions to help us unravel forces at the root of this problem:
- If [renewable energy] technologies exist, are cost effective, and help minimize climate-forcing emissions, why aren’t they diffusing more rapidly?
- Furthermore, why aren’t government policies to promote them, about which there is substantial scientific and social consensus, more aggressive or effective?
The answer he suggests is carbon lock in. What is it? How has it become major inertia to change by reinforcing power structures in society, business, and politics?
Tags: carbon lock in
Posted in behavior, climate economics, policy, social science, technology, transportation | 6 Comments »
“Can Biotech Food Cure World Hunger?”
Friday, October 30th, 2009
A full-throated debate at the NY Times today.
As I’ve alluded to before, my main criticism is that the technology advocates need to get out of their bubble and consider the social implications of these technologies as well as social forces that cause famines in the first place—namely, poverty and poor food distribution. You can increase yields as much as you want, but if people can’t afford or gain access to food, they will starve.
Related post: Food and population defy simplistic portrayals
photo credit: http://www.flickr.com/photos/sarniebill/ / CC BY 2.0
Posted in food and agriculture, technology | No Comments »
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