Climate change is here, but we can fight back
 ecause carbon-based fuels permeate so much of our economy—our electricity sector, our transportation sector, industrial processes, home heating—and cut across so many fuel types like coal, natural gas, oil, as well as some less common sources like shale, it’s hard to wrap your mind around what would it mean to be moving away from these types of fuels,” says Tracey Holloway.
An associate professor of civil and environmental engineering, atmospheric and oceanic sciences, and environmental studies, Holloway uses computer models of the atmosphere to assess how energy choices affect the environment.
“We all know that burning of carbon-based fuels releases carbon dioxide,” she says. “If you’re filling up the gas tank in your car, and drive it 100 miles and the gas tank’s empty, where did the gas go? It went into the atmosphere, mostly as carbon dioxide.”
Alongside traditional air pollutants, carbon dioxide continues to play a key role in changing atmospheric behavior, or climate change.
While carbon dioxide is a naturally occurring atmospheric constituent, global land use changes— deforestation, for example—and fossil fuel use over time have contributed to greatly increased environmental carbon dioxide levels, says Holloway, who directs the Center for Sustainability and the Global Environment (SAGE) in the UW-Madison Nelson Institute for Environmental Studies.
Natural, pre-industrial levels of carbon dioxide were about 280 parts per million–so, within every million parts of air, 280 are carbon dioxide. “Just this natural blanket—the 280 parts per million of carbon dioxide—has made the earth warm enough to be habitable,” says Holloway. “But the totally non-disputed, fundamental physics is that if you add more carbon dioxide, the first order effect you’d anticipate seeing is a warming of the planet.”
In the past 200 years, atmospheric carbon dioxide levels have risen to about 370 parts per million. Based on ice core records, that 370 parts per million is the highest concentration in the last 400,000 years, says Holloway.
Yet, the planet isn’t warming uniformly because global climate systems aren’t uniform. Clouds reflect incoming solar radiation, water vapor amplifies warming, oceans transfer heat, ice caps build up under cold climates and melt under warm climates. In addition, locales near the equator receive more direct sunlight, while the poles receive less. “And all of these processes mean that the impact of these global atmospheric changes is going to be felt differently in different places,” says Holloway.
In other words, sea levels and global average temperatures will continue to rise and ice caps in the northern hemisphere will continue to melt. Yet, there are exceptions to the rule. “In some areas, ice caps are actually growing, but not because global warming isn’t happening,” she says.
For example, in the Upper Midwest of the United States, the “warming” part of global warming means there’s more water vapor in the air that can turn to snow or rain. There, increasingly extreme precipitation events will likely lead to more snow, greater rainfall and increased flood risk.
The good news is that even though the climate trajectory seems headed toward catastrophe, many developing energy technologies use fossil fuels more efficiently, or not at all. Wind, solar, nuclear, geothermal, hydropower, and a few other energy-generation technologies are “zero-carbon” energy options, while biofuels, for example, make use of carbon stored in plants. When they burn, they emit carbon dioxide—but new plants take up carbon as they grow. “In theory, it’s a closed cycle,” says Holloway. “If you’re always burning wood and then that wood is re-growing, you haven’t added to the burden of carbon dioxide in the atmosphere—you’ve just kept it steady.”
In addition, people can make individual changes that will pay off in both the short term and in the long run. “And one that is usually viewed as sort of the lowest-hanging fruit is energy conservation,” says Holloway. “That is win-win-win. It often pays itself back, you’re not wasting fuel, and you’re reducing carbon dioxide per amount of energy you consume.”
People can reduce their carbon footprint by reducing their heating and cooling needs, driving less or driving fuel-efficient vehicles, purchasing energy-efficient appliances, supporting “green” energy-generation efforts, and buying organic, locally grown food. Even eating vegetarian, or eating plant-based meals more often, can make a difference because meat production is a carbon-intensive process.
These individual choices, says Holloway, can have a broader impact by stimulating the market for energy-efficient technologies, communicating public values to policy-makers, and potentially setting an example for others. “There’s no one right answer, but understanding the options available and the impacts of different personal choices allows individuals to make informed decisions,” she says. “And if this is something that someone wants to dedicate time and energy to, they could really have a huge impact.”
Working through SAGE with partners 1000 Friends of Wisconsin and Madison Gas & Electric, UW-Madison graduate student Ann Shudy Palmer developed a website (www.co2gether.org) that enables MG&E customers to track their carbon dioxide footprint over time, as well as participate in discussion groups, research carbon offset options, learn about climate change, and more. “Each individual action is part of the whole,” says Holloway.
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