Greenhouse Gases or Green Homes?

March 21, 2007

American writer Charles Warner famously quipped, "Everybody talks about the weather, but nobody does anything about it."

As it turns out, we are doing something about the weather. And it isn’t pretty. Most climate scientists agree we are changing if not the day-to-day weather, then at least the global, decade-to-decade climate. Until recently, this climate modification has gone on without our knowledge or conscious control.

Rich MacMath, an architect for Austin Energy's Green Building Program, believes now that we know there's a problem, we can do something positive about it.

“My talk tonight will be in two parts: the bad news and the good news,” he said as he began his February 9th lecture at the University of Texas at Austin. The invited talk was part of the Hot Science-Cool Talk series sponsored by the Environmental Science Institute and the Jackson School of Geosciences. He focused on ways that humans are harming the planet and how we can reverse these negative trends through the decisions we make in our own homes and businesses.

“I’m a good news guy,” he said, “so I’m going to go through the bad news fast.”

The Bad News

- The “human footprint,” or part of Earth’s land surface we influence, is 83 percent. That influence comes from direct settlement, agriculture, roads, railways, and light pollution, among other things. The audience was audibly surprised to hear that the place on the planet with the greatest human influence is Brownsville, Texas.

- Humans have caused carbon dioxide levels in the atmosphere to rise sharply in the past century, mainly through burning fossil fuels. This in turn has been linked to global warming.

-Ninety percent of what we make is discarded in less than a year. “In 2007, our problem is abundance,” said MacMath. “We are using so much so fast that the planet can’t take it.”

- The “ecological footprint,” or amount of land and sea it takes to support an average person with food, water, housing, energy and other needs, in the U.S. is 24 acres. If the world were evenly divided up, each person on the planet (6 billion and rising) would get just 5 acres.

- Fossil fuels, our dominant source of energy, have a large footprint. They require about 1600 acres per megawatt of power, compared to just a few acres for solar cells, thermal solar collectors and wind turbines.

University of Texas at Austin students explain to the public how their solar car works. Before each Hot Science-Cool Talk, teachers, students and members of the public get to watch demonstrations such as this, as well as get classroom materials and snacks.

The Good News

“We can reduce our impact on the planet by 75 percent and not sacrifice comfort at all,” said MacMath.

He said the technology and know-how already exist. The answer is green building—using energy efficient designs, materials and appliances, disposing of construction waste in an eco-friendly way, using recycled materials where possible, and generating energy on-site with solar panels or wind turbines.

Green building reduces the human footprint. It also reduces greenhouse gas emissions that drive climate change.

“Global warming is not inevitable,” added MacMath. “We have a choice of whether it happens or not.”

Easy Being Green

Austin Energy is the community owned utility company providing power to Austin, Texas and surrounding areas. The utility sells more renewable energy (primarily from wind turbines in west Texas) than any other electric utility in the country.

There is now a waiting list for customers who want to switch to “green energy.” As an incentive, the cost of green energy is locked in for ten years, so those who have participated since its introduction in the late 1990s now pay less for their electricity than those who subscribe to conventional energy.

In 1991, the Austin utility started the country’s first sustainable or green building program. Dozens more have sprouted around the country since then.

The Green Building Program, recently featured on the PBS program This Old House, offers rebates, loans and other incentives for people who buy Energy Star appliances, install solar panels and build or remodel using green building principles. Rich MacMath is one of several employees in the program who help businesses, contractors and homeowners incorporate those principles into new construction and remodeling projects.

“My job every day is to make Austin the best place to live,” said MacMath.

He also pointed to solar panels as a way that individuals could directly help lower greenhouse gas emissions.

“We have the technology down,” he said. “We have distribution and manufacturing down. The only barrier now is cost.”

In Austin at least, that barrier is shrinking. After an Austin Energy rebate and federal tax credits, a $20,000 solar system would cost the homeowner just $4,500.

How to Light Up a Crowd

MacMath, an animated speaker, handed out compact fluorescent light bulbs throughout the talk to audience members who could correctly answer questions such as: “Why do levels of carbon dioxide in the atmosphere go up and down throughout the year?” or “How much of the energy stored in coal is used up in the process of digging it up, transporting it across the country and burning it?” (The answer to which garnered me one of the highly prized bulbs.)

Compact fluorescent light bulbs use much less energy and last much longer than traditional incandescent bulbs. The cost of running a fluorescent bulb for 10 years is about $150, while the cost of an incandescent bulb is about $600.

“Changing your light bulbs are the best investment you can make,” he said, “unless maybe you invested in Google a few years ago.”

He also put in a plug for plug-in hybrid cars as a way to reduce harmful greenhouse gas emissions.

Coal Debate

There is a debate going on in Texas right now over a proposal to build several new coal fired power plants. The proposal has been controversial because of concerns over increased air pollution that affects human health and greenhouse gas emissions that affect climate.

MacMath would prefer to see improvements in energy efficiency that reduce our need for power. He said it’s cheaper to reduce energy use by a certain amount than it is to generate that same amount of energy.

He introduced the term “negawatts” – a measure of energy savings. If, for example, you made gains in efficiency such that you needed a megawatt less of energy, then in a sense, you’ve actually created a negawatt.

“Negawatts are cheaper than megawatts,” said MacMath. “If you have enough negawatts, that’s a power plant you don’t have to build.”

As a bonus, if reductions come about because you hire a local company to remodel your home or you purchase energy efficient appliances from a local retailer, you are keeping more money in your own town. More coal plants, he said, mean more money for coal companies elsewhere.

MacMath said if you ask the same old questions, you’ll get the same old answers.

“If the question is asked, ‘How are we going to get more power for a growing population?,’ you’ll get the answer: ‘Build more power plants,’” he said. “If the question is, ‘How do I reduce demand?,’ then you open up new possibilities.”

Two homes rated as "Five Star" by Austin Energy's Green Building Program (in blue and green) use much less electricity (and are responsible for far fewer greenhouse gas emissions) than an average home (in red).

And the possibilities do seem wide open.

MacMath noted several positive trends. He quoted a September 2006 study by the National Association of Home Builders: “Green building will reach its ‘tipping point’ by 2007 using conservative estimates. This is profound. As any industry crosses from being ‘less involved’ to ‘more involved’ it means the rest of the industry will be forced to follow and the green homes of today will become the standard homes of tomorrow.”

Public awareness on climate change is also shifting.

“More people are aware of climate change than are not,” said MacMath. “We are at the crest of a wave.”

The City of Austin recently proposed a plan to become the leading city in the nation in the fight against greenhouse gas-induced global warming. According to an Austin Energy brochure, “The plan seeks to eliminate carbon dioxide emissions from virtually all municipal activities by 2020 and establish carbon-neutral standards for new construction in Austin as well as efficiency upgrade standards for current structures.”

In the realm of green building, Austin’s proposed plan would: require all new single-family homes to be “zero net-energy capable” by 2015; increase energy efficiency in all other new construction by 75 percent by 2015; require energy efficiency improvements in existing homes and buildings at the point of sale; enhance incentives and requirements for the city’s Green Building Program; and develop a “carbon neutral” certification program.

“Austin is going to lead the country in reducing greenhouse gas emissions,” predicted MacMath.

by Marc Airhart

For more information about the Jackson School contact J.B. Bird at jbird@jsg.utexas.edu, 512-232-9623.