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Frontiers in Earth Science Study Guide (page 3)

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Updated on Sep 26, 2011

Can We Predict Hurricanes?

Similarly, predictions for hurricanes are improving. Now, using temperatures of the surface of the Atlantic Ocean during the Northern Hemisphere's late summer and early autumn, climatologists often can say, in general, whether the hurricane season will be mild or severe. But the details of predicting hurricane formation and pathways are exceedingly difficult. The dynamics of Earth's atmosphere are complex. Think how often during the autumn we sit in front of a television, with a hurricane just a couple days away from the coast of Florida or North Carolina, without absolute predictions about the hurricane's specific path.

How Will the Increased Loads on the Biosphere of the Nutrients Phosphorus and Nitrogen Change Ecosystems?

Humans are adding enormous amounts of phosphorus and nitrogen to the biosphere, mainly to fertilize crops. How will these increased amounts alter the chemistry of environments, of the soils, lakes, and coastal ocean? How will the altered chemistry change the types of species in those ecosystems? Finally, can more precision farming techniques keep the benefits of fertilizers but reduce the amounts used? Can organic farming substantially reduce the amount of fertilizer while keeping up the productivity of soils, in a sustainable world?

Are There Other Surprises in Store for the Dynamics of Planet Earth?

The discovery of the ozone hole above Antarctica during the Southern Hemisphere springtime was cause for concern to people living near the hole—that is, in Australia and New Zealand. The ozone hole was a surprise. Scientists did not predict it. The hole is a stunning example of the complexity of the earth's surface system. As noted previously in the discussion of feedbacks, the biosphere is complex, with many feedbacks. How many more surprises await us in the future?

How Did Life Originate? Did That Require Special Conditions on the Earth 4 Billion Years Ago?

Conditions on the early earth were quite different. It was almost certainly warmer, because of an atmosphere with a high greenhouse effect. Also, the air had no oxygen. Continents were tiny. The ocean's chemistry of that time is unknown. Could life have originated only in very special chemical conditions on this early earth? How did simple organic molecules assemble themselves into complexly coordinated, self-replicating living cells? This is a question that brings together the earth scientists as well as the biologists, because we want to know what the geological conditions were back then.

Is There Life Elsewhere?

To return to the cosmic perspective with which we began this book, note that astronomers have now discovered more than 100 planets around stars other than our sun. They find these planets by measuring tiny wobbles in stars, caused by the planets' orbits around their star. Just recently, a couple of new planets have actually been visualized as well.

The planets found so far are all huge, bigger than Jupiter. That's because the huge planets are the ones that cause large enough wobbles in their stars for us to observe. But also astronomical instruments are becoming more and more refined. Is there life else where? If so, it is intelligent? The first question might even be answered positively as we explore our neighboring planet Mars in more detail. The second question will have to await not only better instruments but better ideas of how to search and what to search for. Perhaps you will have some answers.

Practice problems of this concept can be found at: Frontiers in Earth Science Practice Questions

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