Noelle Swan

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Invasive Plant Finds Fertile Ground in Allston-Brighton

In Uncategorized on October 4, 2011 at 12:33 pm
This article was first printed in The Allston-Brighton TAB on September 23, 2011 and online on October 4, 2011.

The plant first appeared in Massachusetts in the late 19th century when it escaped from a Cambridge garden. In recent years, it has staged a hostile take over of the state’s parks, yards, meadows, and woodlands. This year, many towns have begun to take aggressive action to control it.

Boston — There’s a new creep in town.

It has been weaving itself through fences and hedges in Allston-Brighton all summer long, plaguing homeowners, gardeners, and landscaper. It goes by the name black swallow-wort.

The plant first appeared in Massachusetts in the late 19th century when it escaped from a Cambridge garden. In recent years, it has staged a hostile take over of the state’s parks, yards, meadows, and woodlands. This year, many towns have begun to take aggressive action to control it.

In many areas of Massachusetts, black swallow-wort threatens the local ecosystem. By sending out runners, or long underground stems, the vine is able to spread over large areas and can quickly overtake a yard or meadow. It produces a crop of green pods that, when mature, turn brown and burst open to release several little brown seeds with white tufts of fuzz that catch the breeze, spreading the plant over long distances. In areas with intact ecosystems, the infestation can be a real problem, upsetting the balance of plants, insects, and even birds.

This summer, in Cambridge, there has been an active campaign to eradicate the plant. Resident volunteers of the “Pod Patrol” scour the city collecting bright green seedpods to either burn or dispose of in a landfill. In Belmont, the Massachusetts Audubon Society’s Habitat Wildlife Sanctuary acquired a meadow completely overrun with black swallow-wort and other invasive plants. The sanctuary attempted to eradicate the weeds by bringing in hungry sheep and goats. Unfortunately, even the animals found the plant distasteful.

In Allston-Brighton the plant poses more of an aesthetic concern than an ecological threat.

“I’m not sure that you can say that there are any native ecosystems in Allston. I wouldn’t know where to look for them,” says Peter Del Tredici, senior research scientist at the Arnold Arboretum and an expert on wild, urban plants.

Del Tredici notes that the major green spaces in Allston and Brighton are planned parks designed to bring nature into the city. “Have you walked along the Charles River?” Del Tredici asks. “There’s nothing native about the vegetation… There are a few native species, but a lot of that was planted. It’s totally a managed landscape.”

For Allston-Brighton, perspectives of the plant as a problem varies widely. “We’re not talking displacing native species here, we’re talking about chain link fences,” Del Tredici says. But he doesn’t hesitate to add that he hates black swallow-wort and aggressively tears it up in his own yard. The best time to pull it is in the spring, he explains. Once it becomes established, it can be difficult to remove. Yanking mature vines does little to affect the overall plant. Individual limbs easily break off the runner, which responds by producing more shoots. Removing the plant this time of year requires some exploratory digging with a trowel or shovel to uncover the entire root system.

Not everyone is interested in evicting the black swallow-wort, though.

“I think it’s kind of pretty,” says Melissa Copeland. The vine has woven a tapestry all over a chain link fence in the backyard of her ranch-style duplex in Brighton’s Aberdeen neighborhood. She says she originally left the vine alone because she thought it could be poisonous and induce a rash, but has since grown to like it.

Will the Buffalo Roam?

In Uncategorized on September 8, 2011 at 4:50 pm

The Kansas State song, and anthem of the American West, “Home on the Range,” brought the longing for “a home where the buffalo roam” to the hearts and lips of nearly every cowboy to sit in a saddle and settler to drive a wagon. Unfortunately, by the time the American settlement of the Plains was complete, and all those cowboys and settlers found their home the American buffalo–or more accurately, bison–was nearly wiped out.

But, recent efforts just might bring the buffalo back to the plains of Montana.

Montana Fish, Wildlife, and Parks has proposed establishing herds of bison in several areas around the state. The creation of herds of 40 to 50 animals would permit managed hunting. Ranchers are skeptical of the state’s assurances that these bison would be disease-free. They fear that wild bison living so close to their homes would pose a threat to their cattle herds. Bison are potential carriers of brucellosis, a disease that can lead to miscarriages.

Today, protected herds of bison already thrive in Yellowstone National Park and on Native American reservations. Yellowstone officials maintain that brucellosis has been effectively managed and controlled within the park.

Bison migrating north of Yellowstone have created a sustained appetite for bison hunts in the area. The area surrounding the towns of West Yellowstone and Gardiner make up some 720 square miles of wildlife habitat. In 2005, the Montana legislature ended a  15-year moratorium on bison hunting with 50 hunting permits. Since, the number of permits issued has increased to 140. The hunts are just as controversial as the current proposal to establish additional herds in other areas of the state, predominantly for the same brucellosis concerns.

Bison and limited bison hunts regularly occur in Utah, Arizona, South Dakota, Alaska, and Wyoming and the Montana officials are quick to point out that such controversy has not arisen in those states.

Yet attitudes toward introducing bison in Montana remain negative. Bison that have migrated away from the protected realm of Yellowstone  often hazed–driven back into the park–or outright slaughtered. As opposed to hunting within a restricted quota and using the meat and skins in a sustainable way, carcasses are left lying on the plains, a scenario reminiscent of the original American settlers’ nearly catastrophic hunting. This persistent problem has resulted in a significant drop in the park’s bison population.

A new iPhone app, Buffalo Haze was released last month, is designed to foster empathy for the modern-day wooly mammoths. The app is a video game in which players “haze” wayward buffalo until they return to Yellowstone. Before playing the game, players are given a brief history of bison and their current plight. Critics say the game makes light of a serious issue and reinforces the notion that the bison belong within the confines of the park.

In the end, it remains to be seen if the buffalo will be free to roam.

Fireworks Blamed for Arkansas Blackbird Deaths, Cause of Fish Kill Still Unknown

In Uncategorized on January 27, 2011 at 4:59 pm

New Year's Eve fireworks are thought to have spooked thousands of red-winged blackbirds, sending them to fly blind into the dark night.

Nearly a month after Arkansas residents found thousands of dead red-winged blackbirds and tens of thousands of dead drum fish, half the mystery remains unsolved.

The 4,000-5,000 red-winged blackbirds that fell from the sky this New Year’s died as a result of blunt trauma, according to tests conducted by several state and federal agencies, announced the Arkansas Game and Fish Commission on Wednesday. Weather radar confirmed the theory that dense swarms of the birds took off together during New Year’s Eve fireworks celebrations. Unaccustomed to flying at night, the birds have poor night vision and are thought to have crashed into buildings, trees, and other stationary objects.

The bizarre event occurred less than 24 hours after 80,000 drum fish washed up on the banks of the Arkansas River. The Game and Fish Commission has conducted similar tests on the fish, but has been unable to find any conclusive cause.

Tests of the river water revealed normal minerals, nutrients, and metals and did not find any toxins. Infections and parasites have been ruled out as well. AGFC Chief of Fisheries, Chris Racey is quick to reassure consumers that fish caught in the river are still safe to eat.

Coupled with the blackbird event, the riverbanks strewn with fish have drawn a lot of national media attention, but fish kills are not uncommon. While pollution and other human interference can occasionally lead to fish kill, in many areas of the nation, these events are simply a natural phenomenon. In Massachusetts, MassWildlife receives so many calls from residents disturbed by riverbanks dotted with dead fish, that they have a web page devoted to reassuring the public that fish kill is often a natural process. This is a seasonal occurrence and can be triggered by many different factors, from diseases to oxygen levels in the water.

Arkansas rarely sees fish kill of this size, but it does experience this type of event annually. “Unfortunately, we probably will never know exactly what killed these fish,” conceded Racey.

Toxic compounds come of age in nation’s schools

In Uncategorized on October 15, 2010 at 10:28 am

Professor Robert Herrick of the Harvard School of Public Health (HSPH) is worried.

“This could be bigger than asbestos and lead issues combined,” he explains. He’s talking about toxic PCBs, which were a major component of building and electrical materials in more than a third of the public buildings, including schools, built between 1950 and 1979, when they were banned by the Environmental Protection Agency.

Today, those materials are nearing the end of their use-life at a time when school budgets are shrinking. The window caulking and lighting fixtures that have sealed in PCBs for 30+ years are breaking down and releasing the toxic compounds into the air where they settle on ceiling tiles, cinderblock walls, even furniture.

Herrick first published evidence of PCBs in public buildings back in 2006 during a preliminary survey of Boston masonry. This year, his suspicions are becoming a reality. Estabrook Elementary School in Lexington, Massachusetts briefly closed its doors to incoming students early this September in order to heavily ventilate the building and bring PCB concentrations in the air back down to a safe level. Just weeks later, Murphy Elementary School in Dorchester, Massachusetts, closed a wing of the school and brought in workers dressed in full-body protective suits to remove caulk with high levels of PCBs.

A pilot program testing for PCBs in New York City schools found unhealthy levels in at least three of the five schools tested. The city is waiting for the results of two more schools that participated in the pilot test before expanding testing citywide. Parents and politicians in Manhattan are demanding that city officials have all 740 New York City schools tested, but according to the EPA and the Toxic Substance Control Act (TSCA), they don’t have to.

While any PCBs found above a certain concentration must be removed, testing is optional. The New York City Construction Authority has worked to reduce the levels of PCBs in those three schools that have already been tested. So far, follow up tests indicate that these efforts were successful in two out of the three schools. Yet, tests at Public School 199 in Manhattan still reveal concentrations above the maximum set by the EPA.

Professor Charles Weschler saw this happen just last year in Copenhagen, Denmark. Window caulking had been identified as the major source of PCBs in the school. Once the caulk was removed, further testing showed that those PCBs had migrated all over the school. He says that this is a problem around the industrialized world. In fact, Finland, Sweden, and Germany have reported PCBs in their schools.

No one knows for sure how many American schools contain PCBs. Yet, experts from universities across the country believe the conditions that are emerging in the northeast are indicative of a national problem. Without mandatory testing, it is difficult to quantify the scope of the issue. Testing requirements are among several PCB issues currently being considered by the EPA as part of its revision of the TSCA. Herrick and his colleagues have submitted comment to the EPA challenging the federal organization to sponsor mandatory testing and work with states on developing plans to respond to the test results. Others are concerned that this would add undue financial burden to the already stressed national budget.

What are PCBs?

The acronym PCBs stands for polychlorinated biphenyls and represents many different chemicals that share a similar molecular structure. Once considered highly valuable compounds, their number of uses rivaled plastic. They were found in electrical equipment, paints, joint compounds and even carbonless copy paper.

In 1979, the Environmental Protection Agency banned the manufacture of any PCBs, citing them as known carcinogens that disrupt immune, reproductive, neurological, and endocrine systems. PCB contamination is not only a problem indoors, but in rivers, soil, and even outdoor air.

Air fresheners may double breast cancer risk

In Uncategorized on September 6, 2010 at 7:11 pm

Photo Credit: Jim Mills

A new study in the medical journal Environmental Health suggests that major breast cancer risks could be coming home in grocery bags. Researchers from the Silent Spring Institute found little correlation between the use of pesticides, but instead discovered that women using air fresheners and scented cleaning products may be doubling their risk of breast cancer through exposure to mammary gland carcinogens and endocrine disruptors.

“Fragrance so often comes with compounds that are endocrine disruptors, chemicals that effect hormones like estrogen which we know increases your risk factor,” warns Dr. Julia Brody, Silent Spring Institute Director and the study’s corresponding author.

She explains that once in the home, these chemicals enter the body in several ways. “They can come in through skin contact, so you have your hands in the bucket or you’re touching the chemicals. You can breath them so if you are using the product and some of it is in the air you are breathing it. In the case of air fresheners, they are always in the air. And you can also ingest them in dust. So they’re in the air but then they attach to dust particles so you accidentally ingest them.”

This comes as unwelcome news to the busy women of the 21st century who have embraced bottled mountain breezes and lavender fields as sources of comfort and household pride. Air fresheners have become so commonplace that they are no longer found solely in spray bottles but plug into the wall and pervade laundry detergents, fabric softeners, hand soaps and body washes. Dr. Brody suggests choosing simpler cleaning products, such as soap and water or vinegar and baking soda and avoiding fragrances. She hopes that this research helps “to really drive a green chemistry movement in a direction towards safer alternatives.”

Investing in America’s Scientific Future

In Uncategorized on August 31, 2010 at 9:21 am

Brett Collins of Chicago, Illinois is exploring the possibilities of superconducting magnetic coils at the University of Berkeley. Katherine Gabet of Columbus, Ohio studies turbulent combustion at Ohio State University. Andrew Hilmer of Oshkosh, Wisconsin studies nanotechnology at Massachusetts Institute of Technology.

And they’re doing it on the national dime.

These students are among the first 150 recipients of the nation’s Office of Science Graduate Fellowship. Office of Science Director Dr. William F. Brinkman is betting they aren’t the last.

In 2009, Congress passed President Barack Obama’s American Recovery and Revitalization Act, designed to spur economic development. The Act was sold as a jobs bill, but it’s bolder and broader than that. It is an energy revolution.

Through it, fellowship awardees receive tuition support, a stipend for living expenses, and research funding for three years.

Transforming the nation’s energy infrastructure takes more than manual labor. It takes inventors, engineers, scientists, and all forms of tinkerers. That’s where the Office of Science Fellowship comes in to play. These students aren’t ready to shatter any boundaries yet, but the Office of Science is willing to bet that someday some of them will. “We are trying to train future scientists for our National Laboratories,” Dr. Brinkman explains. Congress isn’t so sure.

Some Republicans feel that President Obama has used the economic crisis to drive his personal agendas. Others are looking to jobs and unemployment rates as the only indicators of success of the original plan. All Dr. Brinkman and his colleagues at the Office of Science can do is wait. Their students aren’t going to make any huge discoveries in time for congressional appropriations committee meetings, but that is where the fate of the program is being decided.

President Obama has requested that funding for the Office of Science increase from $4.904 billion in 2010 to $5.121 billion for 2011. In late July, the Senate approved a median figure of $5.012 billion, that’s $109 million shy of the Presidents request, but still $108 million more than last year’s budget. Either would be good news for the fellowship.

Representative Ed Pastor (D) of Arizona introduced the House appropriation recommendations with an impassioned speech citing the BP gulf spill as a wake up call that we need to be forging ahead with our energy revolution. Yet the bill Rep. Pastor has presented to the House of Representatives does not come close to Obama’s or the Senate’s requests for the Office of Science. Instead, the House appropriation bill offers up $4 million dollars less than was allotted in 2010. That could be devastating for the fellowship.

Newton Residents Find that Rainwater Collection Brings More than Financial Savings

In Uncategorized on May 24, 2010 at 12:46 pm
First published in the Newton TAB on May 24, 2010.
Newton —Newton resident Ellen Meyers loves her rain barrel. She doesn’t know for sure how much money it has saved her. That’s not why she purchased it.

“I just felt so good about using less water,” she said.

Many Massachusetts residents are supplementing their water supply with rainwater collected in barrels. Bypassing the tap means bypassing the need for tanker trucks, processing plants, and treatment chemicals. These processes are vital to filter and deliver water for drinking, cooking, and bathing. But water has many other uses.

Maria Rose, an environmental engineer for the city of Newton, said that residents in dry states like Nevada and New Mexico have long considered rainwater collection a critical aspect of daily life. However, the Northeast typically gets 45 inches of rain a year. Rose sees in this figure, an enormous potential for rainwater harvesting.

From just one inch of rainfall, Rose said, a 1000 square foot roof can capture 623 gallons of water– that’s 15 bathtubs full of water falling on a three-car garage. The larger the roof, the more rain can be collected. The soon-to-be-opened Newton North High School will rely on harvested rainwater to maintain the school’s extensive grounds.

Large-scale rainwater collection systems cannot only irrigate large plots of land, but can be brought indoors. Rainwater running off of the roof can be funneled into underground tanks. Water in these tanks can be pumped into the building where it can supply water for flushing toilets and washing laundry.

While such systems are likely to become cost effective over time, they are expensive to install and can require extensive renovations.

Water conservation need not be so high tech, Rose said. Simple solutions can help to save water, no matter where it comes from. Residents can use soaker hoses with lots of little holes allowing water to bubble out slowly instead of sprinklers and that they make sure they aren’t watering sidewalks, driveways, or the side of the house.

Rainwater collection can also be low tech. The industrious homeowner can craft a rain barrel using a couple of power tools, a handful of parts from the hardware store and a large, plastic barrel.

The city of Newton encourages residents to invest in rain barrels and co-sponsors a group-purchasing program each spring with New England Rain Barrel Company of
Peabody, Massachusetts. The barrel itself, a repurposed food storage container, is a blue, 55-gallon, plastic drum with a top and bottom spigot. The bottom spigot attaches to a garden hose and the top spigot remains open releasing overflow. The system is entirely powered by gravity as rainwater rides down the gutter, into the drum, and flows out the hose.
For homeowners who prefer something to match their patio décor, online options range in price from $75 to $300 and range in style from the unapologetic, plastic drum to the Canadian, spruce cabinet.

Any of these systems requires a certain level of maintenance. Screens and lids keep out some debris and insects. Because it is a tank of standing water, the barrel is an ideal habitat for mosquitoes and bacteria. The New England Rain Barrel Company recommends shading the barrel from direct sunlight and rinsing it out when the water gets low to help reduce algae growth. Application of oil or commercially available “mosquito dunks” can keep the surface waters from turning into a mosquito nursery.

David Gordon of Newton Centre has found that this occasional maintenance is minimal and worth the effort. Water conservation is an important issue to him, both personally and professionally in his organic lawn care business. He says the switch from the tap to rain barrels felt like a reasonable step in the right direction.

“It’s not like I thought it would save the world or anything. It just seemed like the right thing to do,” he said.

EEA takes Massachusetts pulse on climate policy

In Uncategorized on May 16, 2010 at 9:37 am

Over the past few years, Massachusetts has taken the national lead in developing a “clean energy economy” and tackling climate change. Governor Deval Patrick signed the Global Warming Solutions Act (GWSA) in August of 2008. This act represents a long-term commitment to slash GHG emission to just 80% of the level that has remained steady since 1990. A short-term goal has been established to reduce emissions by 10-25% by 2020. Secretary Ian Bowles of the Executive Office of Energy and Environmental Affairs (EEA) is charged with setting a specific goal within this range by January 1, 2011.

The EEA’s Draft Climate Implementation Plan identifies existing and potential measures that could be taken by the transportation, building, and energy sectors. Existing and anticipated policies include adoption and implementation of various international, federal, and regional standards and regulations. Projection models indicate that these measures alone are likely to result in a 19% GHG emission reduction by 2020. While this is well within the range of 10-25% set by the Global Warming Solutions Act, the EEA has identified several other areas holding potential for emissions reduction.

The question is, how much of a commitment are the people of Massachusetts willing to make?

The EEA will take the pulse of Massachusetts’s residents on this very issue at a series of public hearings scheduled to take place throughout the state next month. Individuals, businesses, landlords, and large companies alike are all invited to weigh-in at one of these hearings or through written comments.

EEA Assistant Secretary for Policy, David Cash described these upcoming public hearings as “hugely important.” His office is casting a wide net amongst potential stakeholders, reaching out to environmental groups, business groups and local municipal groups. Still, he says it’s hard to gauge who will show up.

The EEA is specifically looking for public comment on 5 questions outlined in the Draft Climate Implementation Plan.

1. Where between 18 and 25 percent below 1990 levels should the emissions limit of 2020 be set and why?

2. What role can Massachusetts state government play in catalyzing the clean energy economy? What policies could inspire entrepreneurship and create markets for clean energy products and services?

3. Over what number of years should cost effectiveness of strategies be evaluated in pursuit of the goals of the Commonwealth for 2020 and 2050? How should future costs be compared to present costs?

4. How should the Commonwealth evaluate and prioritize strategies to achieve 2020 and 2050 goals?

5. How should green house gas reduction strategies be valued or prioritized?

Individual hearings will be held in Boston, Pittsfield, Worcester, Lowell, Lakeville, Springfield, and Woods Hole between June 1 and June 22. Additional comments can be submitted via email at climate.strategies@state.ma.us.

Is Fracking Just a Dirty Word?

In Uncategorized on February 4, 2010 at 12:00 pm

With cap and trade initiatives temporarily sidelined in Washington, the dialogue has changed from emissions reduction to energy independence and job creation. Without missing a beat, the Chairman and CEO, Rex Tillerson, of Exxon Mobil appeared before the House Subcommittee on Energy and Environment on January 20, 2001, presenting hydraulic fracturing as the key to both.

Hydraulic fracturing, or fracking, is a process for extracting oil and natural gas from beneath shale by injecting fracking fluid, (water mixed with small amounts of chemicals), at very high pressures into the ground, forcing out fuel. The technology has been around for a century and has been used in Exxon Mobil oil wells for 60 years. Today, 90% of the nation’s oil and natural gas wells already employ this technology.

Why then, is Tillerson campaigning for an already thriving technology?

Tillerson is trying to paint an image of fracking as a technology that helps us achieve energy independence while creating jobs, ensuring fossil fuels keep the lead role in America’s evolving energy paradigm.

This image is more important today than it ever has been in it’s 100 year history.

For the past year, fracking has been under attack.

NPR reported last May that Texas, Ohio and Colorado residents claim that fracking has polluted their wells. These accusations have yet to be confirmed. It is difficult to analyze any link between contamination of well water and fracking fluid because the chemical compounds utilized are carefully guarded industry secrets.

In 2005, fracking was granted an exemption from the Safe Drinking Water Act taking regulation out of the hands of the Environmental Protection Agency. Vice Chair of the Committee on Energy and Commerce, and Colorado Representative Diana DeGette has introduced a bill in the House that would repeal this exemption. Senator Bob Casey of Pennsylvania has introduced a comparable bill in the Senate.

While the passage of DeGette and Casey’s bills would be a victory for the Obama administration’s expressed desire to reverse the policies of the Bush-era EPA, it may not be crucial to the fracking fluid disclosure cause. In the absence of federal regulation, individual states have begun to request disclosure of fracking fluid contents.

Gas executives from Chesapeake Energy and Range Resources have joined the call for disclosure. This stance is an interesting power play. In addition to continuing the heavy role of fossil fuels in America’s future energy paradigm, this also places reform out of the hands and budgets of energy suppliers.

Fracking is performed by independent contractors, including ther firm Americans love to hate, Halliburton. It is these contractors that hold the recipes to fracking fluid. Aubrey McClendon of Chesapeake Energy can publicly declare, “we need to disclose the chemicals that we are using and search for alternatives,” because it is not his company that will bear the cost of such endeavors.

Environmentalists, worry that any disclosure initiated by the industry might be insufficient and hold out hope that Congress will move to bring the process back under federal regulation.

Sources:

http://degette.house.gov/index.php?option=com_content&view=article&id=852:gas-execs-call-for-disclosure-of-chemicals-used-in-hydraulic-fracturing&catid=66:in-the-news&Itemid=195

http://www.newsweek.com/id/154394

http://www.npr.org/templates/story/story.php?storyId=104565793

http://www.ordons.com/201001242478/exxon-mobils-tillerson-advocates-for-fracking.html

Taking the Guilt Out of Air Travel

In Uncategorized on January 28, 2010 at 5:29 pm

Americans work hard for their vacations. U.S. businesses are notoriously stingy with vacation time and their employees like to make the most of what time they can get.

While a trip to a foreign country for Europeans can be a quick drive over a border or two, Americans travel farther and rely more heavily on air travel. Those flights that carry us across oceans and language barriers leave behind a wake of carbon dioxide in the stratosphere.

I will not be boarding a plane for spring break this year, so rather than stew in jealousy, I thought I would take a peek at my friends itineraries to get an idea of the impact of various spring breaker destinations.

The UC Berkeley Environment and Sustainability Portal estimates that an escape from snowy Boston to sunny Jamaica deposits 1.23 tonnes of CO2 in the atmosphere over the course of the 5000 mile round trip. Berkeley further suggests that a modest donation of $13.39 each to the UC Berekeley Climate Action Fund will sufficiently offset the emissions of their trip. CO2 Balance suggests a $22.04 donation to send energy efficient stoves to the developing world.

A trip from Boston to Cancun, Mexico yields similar CO2 emissions as the Boston to Jamaica trip. A vacation to Hawaii, the most distant sun seeker destination, results in more than twice the CO2 emission at 3.2 tonnes per seat and surpasses even transatlantic flights.

Whether or not these calculators are accurate is debatable and much discussion board space has been devoted to their critique. Their principle, however, is highly intriguing. Environmentally conscious businesses have been purchasing offsets to their travel for several years now. These web based calculators and small scale offsets have brought an easy and affordable way for the individual travelers to compensate in a small way for the massive fossil fuel use included in their ticket price.

Sources:
“Air Travel Calculator.” UC Berkeley Environment and Sustainability Portal.
http://enviro.berkeley.edu/aircalculator. Last accessed January 21, 2010.

“Air Travel Carbon Dioxide Emission Calculator.” CO2balance.com.
http://www.co2balance.com/us/co2calculators/air-travel. Last accessed January 21, 2010.