Earth and environmental sciences seek to understand the planet on which we live and our relationship to it. During its 4.5 billion years of existence, Earth has undergone enormous physical changes. Our planet has been bombarded by asteroids, meteorites, and solar storms. Remnants of such externals forces are still visible, such as the crater of an asteroid collision off the coast of Mexico’s Yucatan Peninsula, which may have led to the demise of dinosaurs 65 million years ago. However, not all of the great changes to our planet have come from space; the evolution of life on Earth itself has played a fundamental role. For example, the emergence of bacteria in the ocean more than a billion years ago transformed the makeup of our atmosphere by producing oxygen as a byproduct of photosynthesis, thus making new kinds of life possible. On land, microbes and lichens broke down rocks and created soil in which plants and burrowing animals could thrive.
The earth sciences explore the three primary regions of our planet—land, sea, and air. Plate tectonics—the theory that both the continents and the oceans move slowly but continuously over long spans of time—guides our understanding of how these regions function and interact. Mountain ranges emerge and earthquakes occur when these plates shift. Volcanic eruptions create chains of islands and expand the ocean floor. These powerful and sometimes terrifying events have natural causes that researchers can investigate and lead to predictions of where future dangers lie.
Large scale planetary changes take place not only on the land and sea, but also in our atmosphere, which contains primarily nitrogen and oxygen. Our atmosphere protects us from harmful ultra-violet radiation and regulates temperature, rainfall patterns, and winds. However, shifts in the atmosphere’s composition have the potential to bring about ice ages as well as dramatic global warming. How should we respond to such environmental changes? To what extent should the state of the environment dictate the way we live our lives?
Scientists have become increasingly curious about how humans impact our environment as our cities expand, technology develops and the world population grows. Environmental problems such as climate change, ocean acidification, overfishing, rainforest destruction, species extinction, dwindling natural resources, and air & water pollution have become increasing concerns over recent decades. As a result, scientists have employed numerous interdisciplinary and synthetic approaches to combat them, to varying degrees of success. Such changes in the global climate and environment raise challenging questions about our relationship to this one and only planet we live on. Is there a moral or theological imperative to protect the environment? When values such as social justice and economic growth conflict, what priorities should drive solutions to population regulation, resource distribution and sustainability? Would it be possible for humans to migrate to another planet or moon?
Dealing with consequences of our activities is an increasingly challenging economic and geopolitical problem, but growing international cooperation both within the scientific community and among the public at large, gives hope that creative and effective strategies will emerge.
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