ACUMEN Spring2023

16 ACUMEN • SPRING 2023 Is it human-caused? Yes, again. “Greenhouse gas emissions, primarily CO2 from fossil fuel burning, are responsible for warming the atmosphere to levels unprecedented in human history.” Is it bad? Another yes. “History has shown that any change in the environment of stable civilizations will be disruptive to those civilizations. Alterations in areas in which crops can be grown, changes in growing seasons, shifting storm tracks and rising sea level could have devastating economic, social and political consequences to modern societies.” Can we do anything about it? “Fortunately, yes,” he says. “Cessation of fossil fuel emissions could stabilize the climate. Until they are overwhelmed, there are natural carbon sinks in the ocean and terrestrial ecosystems that can absorb previously emitted carbon and return global climate to a stable state.” Is it worth doing anything about? “Absolutely, yes,” he says. “It is much cheaper to prevent it than to cope with it later. It’s only going to get worse if we don’t.” So, the real question is this: What do we do about it? “The choice is between mitigation or adaptation,” he says. Climate mitigation would entail trying to slow down or stop climate change, he explains. This would need to happen primarily through reducing the use of fossil fuels and cutting back on deforestation, which both contribute to the amount variability over time. This process allows him to assess how things like vegetation, fire, climate and moisture have changed over the course of thousands of years. And, he’s seeing the same thing over and over again. “Long-term records suggest that in many areas, we’re moving into unprecedented kinds of temperature and precipitation combinations,” he says. “Records of the past can inform our understanding of natural variability and the potential impacts of current changes; however, the hard evidence of ongoing and recent climate change is shocking.” So Now What? The Debate Between Adaptation and Mitigation Dork Sahagian is a professor of Earth and environmental sciences and also likes to turn to science to discuss the existence of climate change and the importance of action. A member of Lehigh’s Environmental Initiative, Sahagian studies the environmental impact of human activities. He has crafted a series of questions to set the stage for what is happening with the climate and how to address it. Is the climate changing? “Yes,” he says. “There are undeniable instrumental data that temperatures are rising, precipitation patterns are changing, and ocean and atmospheric circulation systems are changing. Arctic ice and boreal snow cover is decreasing, storm tracks are changing, and disease vectors are emerging.” Bob Booth (right) studies how climate change has impacted ecosystems over time. Dork Sahagian (far right) addresses the impact of human activity on the climate. CHRISTINE KRESCHOLLEK

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