Life and death on planet earth summary

Solo disponible en BuenasTareas
  • Páginas : 5 (1001 palabras )
  • Descarga(s) : 0
  • Publicado : 24 de agosto de 2010
Leer documento completo
Vista previa del texto
“The Life and Death of Planet Earth: How the New Science of Astrobiology Charts the Ultimate Fate of Our World,” written by Peter D.Ward a professor of geological science and zoology at the University of Washington, and Donald Brownlee a professor of astronomy at the University of Washington, coauthors of Rare Earth a bestselling book, question the reader about how the world will end, if it willend in fire or ice, claiming that one-day the Earth will be just like Mars, a desert wasteland.
In the book, both authors mention that our planet is middle aged, is in decline, and we are experiencing a turbulent period in human history. In the first chapter, Warn and Brownlee start prophesying Earth’s distant future explaining briefly different Earth eras such as the Cenozoic, Mesozoic, and thePaleozoic. In addition, they state their reasons to write this book, stating that they can write it because they are scientists, and because they are curious. Furthermore, they mention that predictions of how our planet can or will change for the worst should illustrate the risks of our present course, and that the depressing future they present in this book, suggests that if our own species isto survive, we must either take steps to sustain the habitability of our own world or find another at a younger condition of planetary life.
On the next chapter, both authors maintain that reverence of life had only been increased by scientific understanding of how marvelous the human body is. They mention that human body is made of more cells than there are stars in the Milky Way galaxy, andthat each cell is a mini city with its own highways, factories, waste-processing plants and a package of DNA recording the genetic instructions necessary to make a copy of ourselves. Warn and Brownlee cite that our home planet is similarly complex, and similarly marvelous, agreeing that to understand how Earth will die we must first understand how it lives. They define Earth as a “terrestrialplanet”, which is mostly made of rock and metal. In addition, they mention the deep effect of Moon in Earth history, and how it has stabilized the tilt of the Earth’s axis, letting our planet’s climate, seasons, and ocean circulation to stabilize. Afterwards, they describe the creation, and development of Earth, mentioning that the mix of land, and ocean in our planet is unique in the solar system, andit is a vital property that has allowed the Earth to be relatively stable, and habitable for as long as it has. In addition, they describe how humans have not only created new ways of producing animals, and plants through severe unnatural selection, but also manipulated the most potent force of evolutionary mass extinction. Finally, they state that humanity has even created a new mass extinctionthat is different from any that had ever affected the planet.
On chapter three, Warn and Brownlee talk about the End of Mother Earth, and maintain that to understand why Earth works so well today we must understand plate tectonics, which maintain a constant planetary temperature by removing some elements and introducing others. They describe that carbon combined with oxygen form carbondioxide, a “greenhouse gas” that warms our planet’s surface by retaining the Sun’s radiant heat. Besides, both authors mention that Earth’s temperature is controlled by plate tectonics, and animals, and plants generate an acid necessary to convert calcium into limestone, which creation removes carbon from the atmosphere, and helps in the temperature regulation process.
Warn and Brownlee, on theirfourth chapter maintain that a first stop in the future is not millions of years from now, but only thousands. They maintain that Sun will be no brighter, that the amount of carbon will be quite similar, as well as the rate and nature of tectonic recycling systems. In addition, they maintain that Earth will catch a cold, and then we will be facing a glaciation that will reduce the amount of life on...
tracking img