Archive for November, 2009
« Older Entries | Newer Entries »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 »
Earth’s oldest organisms reacting to climate warming
Monday, November 16th, 2009
Imagine being a tree growing incredibly slowly for the last 4,600 years and then suddenly experiencing a significant growth spurt in the last half century.
In this week’s early edition of the Proceedings of National Academy of Sciences (open access), Matthew Salzer and colleagues report that several stands of bristlecone pines growing at treeline in California have experienced such a jump.
The growth of trees at high elevation is often limited by temperature. There has been debate among plant physiological ecologists as to why this is the case. It appears that tissue formation is limited in this species by very cold conditions. By warming up climate, trees are able to create wider growth rings. The result is faster growth and a great paleothermometer to help us further document the significance of modern climate warming.
The researchers also factored out possible effects of precipitation and CO2 fertilization, indicating that the growth increase, unprecedented over the past several millennia, is likely caused by temperature.
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Photo credit: http://www.flickr.com/photos/mariozama/ / CC BY-NC-ND 2.0
Posted in climate change science | No Comments »
This week’s good ideas in campus sustainability: 11/16/09
Monday, November 16th, 2009
This week’s showcase includes Furman University and Emory University…
Posted in campus sustainability, higher education | No Comments »
How do women respond to household chemical exposure?
Sunday, November 15th, 2009
Every day, we are exposed to a cocktail of synthetic chemicals from consumer products. How harmful are these? In an earlier post, I described how risk analysis is an important scientific process for determining exposure, effects, and overall risk of these chemicals.
One thing missing from these analyses is how people respond to information about their chemical exposure. In a recent issue1 of the Journal of Health and Social Behavior, Rebecca Altman and colleagues addressed this by analyzing what they call the “exposure experience” of women in Cape Cod, MA—an area with elevated breast cancer rates.
What did they find?
Posted in gender, pollutants, risk analysis, toxics | 2 Comments »
In this week’s issue of Science: Climate communication —Has ‘climate fatigue’ set in?
Saturday, November 14th, 2009
Richard Kerr asks this question1 amid new polls by Pew and Gallup suggesting that fewer Americans (from 2007 to 2009) think warming is happening (71% to 51%) and that the seriousness of warming is being exaggerated (30% to 41%).
Scientists and politicians have been doing their part to convey the seriousness of our situation:
- Chris Field (Stanford ecologist): We are basically looking now at a future climate that is beyond anything that we’ve considered seriously.
- Ban Ki-moon (UN Secretary General): The [2007 IPCC] report is a wake-up call. The time for hesitation is over.
- Stephen Schneider (Stanford climate change scientist): Things are looking much worse than was thought in the 1970s and ’80s.
But Roger Pielke, Jr. suggests that climate scientists may have boxed themselves into a corner after such a strong consensus statement in the 2007 IPCC report: “Where do you go after ‘unequivocal’?”
One direction, which some scientists have turned to, has been to ramp up the sense of urgency by emphasizing how changes in the Arctic are happening faster than expected, as we saw in the last post on accelerating Greenland ice thaw. As someone who studies climate impacts in boreal and Arctic ecosystems, I can attest that this approach is not exaggeration.
However, this may not be working. Matt Nisbet suggests there is still a messaging and communication problem:
“[I]t’s very difficult for any single [climate] event to break through competing issues and information.” For Americans, those issues now include two wars, a lurching economy, and health care reform. “Given the complexity of climate change,” Nisbet says, “any one event will be downplayed [by partisan critics]. I think the real long-term challenge is public education, to prepare people. What does it mean to be an American in an era of climate change?” Climate scientists need to refocus their message, he says, from the broad sweep of global warming to small regions such as New England and the Southwest and to immediate issues such as personal health. At the same time, new conduits to individuals need to be created to replace crumbling traditional media. A tall order (underlining mine).
That’s part of the purpose of this blog, and it needs to become part of the mission of higher education.
Update: Nisbet also wrote this week about the reach of scientific claims at his blog, Framing Science.
Related 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
- Why don’t people engage climate change? Problem 4: Political-economic context
- Why don’t people engage climate change? Problem 5: A perfect storm of climate change denial
1Kerr, R. (2009) Amid worrisome signs of warming, ‘climate fatigue’ sets in. Science 326:926.
Posted in communication and framing, environmental literacy, higher education | 1 Comment »
In this week’s issue of Science: Greenland ice loss is accelerating, and now we know why
Saturday, November 14th, 2009
Greenland and Antarctica are two places that climate scientists are studying intensely because of the potential for significant sea level rise were they to melt. Over the past 20 years, scientists have used a variety of methods to track ice loss, and they have found that Greenland has been losing ice more rapidly over the past decade than it had in the 1990s. In fact, since 2004, ice loss has accelerated to such a high level that Greenland is now losing about 270 billion tons of ice per year. Greenland’s contribution to sea level rise has been about 0.13-0.74 mm/yr, or about 4-23% of global sea level rise observed from 1993-2005.
In this week’s issue1,2 of Science (subscription required), Michiel van den Broeke and colleagues used a couple of methods to confirm that this acceleration of ice loss is real and to understand why it’s happening.
The extent of ice in a glacier is like a bank account, but instead of money, we’re keeping track of ice. When inflows (precipitation = snow) exceed outflows (mostly due to melting and runoff), the ice sheet gets bigger, just like a bank account grows when deposits exceed withdrawals. We say that there is a positive surface mass balance. When outflows exceed inflows, then the ice sheet shrinks, and we say there is a negative surface mass balance.
They found that before 1996, Greenland’s ice sheet had a positive mass balance (getting bigger) because precipitation exceeded runoff. Between 1996-2004, precipitation and runoff both increased, and since these roughly cancel out one another, the ice sheet didn’t change much. However, after 2004, precipitation stopped increasing while runoff continued to rise exponentially. Mass balance has been negative for about five years now, with a cumulative mass loss of almost one trillion tons of ice in that span. Amazing.
The next big question, therefore, is what’s causing precipitation to change? Will it go back up, thereby reversing the ice loss, or will it remain the same or decrease, causing loss to continue accelerating? Nobody knows at this point.
1van den Broeke (2009) Partitioning recent Greenland mass loss. Science 326:984
2Bowdoin people can access the article here.
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Photo credit: http://www.flickr.com/photos/chrissy575/ / CC BY-NC 2.0
Tags: Greenland
Posted in climate change science, polar ice, sea level rise | 2 Comments »
A big accomplishment in green design
Saturday, November 14th, 2009
When I taught at Carleton College (Northfield, Minnesota), I watched from across the river as St. Olaf College constructed a new science center. It is not just another college building; it’s the largest academic facility in the U.S. to receive LEED’s highest rating of platinum.
This past summer, I was back in Minnesota and toured it firsthand. It’s a great building—very functional but visually stunning. Congratulations, Oles. You deserve a lot of credit for setting the bar high.
The real value of this building, in my opinion, is whether St. Olaf can use it as proof of concept for all future construction rather than it becoming the token green building on campus. That’s when green design becomes a game changer in campus sustainability.
Excerpts:
St. Olaf College’s Regents Hall of Natural and Mathematical Sciences has earned platinum certification — the highest rating attainable — from the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) rating system. The nearly 200,000-square-foot, $63 million building is the largest and most complex academic facility in the nation to earn the prestigious platinum rating.
“Actions speak louder than words,” says St. Olaf President David R. Anderson ’74. “The LEED Platinum designation for Regents Hall demonstrates, once again, St. Olaf’s leadership among American colleges and universities in sustainability practices.”
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Photo credit: Photo courtesy of St. Olaf College
Posted in campus sustainability, higher education, sustainability | No Comments »
Climate Literacy—A new blog
Friday, November 13th, 2009
Here’s a new blog to keep an eye on. It’s called Climate Literacy by Mark McCaffrey in the Cooperative Institute for Research in Environmental Sciences at the University of Colorado.
It’s aims:
Because climate science is inherently interdisciplinary, it can fall through the cracks in traditional science education. Students sometimes graduate from high school or even college without learning climate basics. Climate literacy is aimed at helping address these gaps.
Related 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
- Why don’t people engage climate change? Problem 4: Political-economic context
- Why don’t people engage climate change? Problem 5: A perfect storm of climate change denial
Posted in climate change science, environmental literacy | 1 Comment »
Solutions
Friday, November 13th, 2009
There’s a new website/journal called Solutions, edited by Bob Costanza, David Orr, Paul Hawken, and John Todd that’s worth looking taking a look at.
Posted in solutions, sustainability, sustainable development | No Comments »
What should every citizen know about ecology?
Friday, November 13th, 2009
That’s the title of a new paper1 by a team of ecologists in the current issue of Frontiers in Ecology (subscription required). They offer several suggestions for the ongoing conversation on environmental literacy.
Here’s their framework for ecological literacy (in a nutshell, excerpts and paraphrases)…
Posted in environmental literacy, higher education, nature and culture | No Comments »
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