Book contents
- Frontmatter
- Contents
- Preface
- Part I The astronomical planet: Earth's place in the cosmos
- Part II The measurable planet: tools to discern the history of Earth and the planets
- Part III The historical planet: Earth and solar system through time
- Part IV The once and future planet
- 21 Climate change over the past few hundred thousand years
- 22 Human-induced global warming
- 23 Limited resources: the human dilemma
- 24 Coda: the once and future Earth
- Index
- Plate section
24 - Coda: the once and future Earth
from Part IV - The once and future planet
Published online by Cambridge University Press: 05 June 2013
- Frontmatter
- Contents
- Preface
- Part I The astronomical planet: Earth's place in the cosmos
- Part II The measurable planet: tools to discern the history of Earth and the planets
- Part III The historical planet: Earth and solar system through time
- Part IV The once and future planet
- 21 Climate change over the past few hundred thousand years
- 22 Human-induced global warming
- 23 Limited resources: the human dilemma
- 24 Coda: the once and future Earth
- Index
- Plate section
Summary
The origin and evolution of Earth involved physical processes that operate on all matter and energy in the universe. The formation of stars is a common phenomenon in galaxies, and the formation of planetary systems is a common result of star formation. Planets are extremely common throughout the universe, and the technology to detect and characterize them continues to improve. Almost 900 planets had been discovered as of the end of 2012, with even more candidates awaiting confirmation. Both the sizes and masses are becoming known for an increasing number of planets, allowing a preliminary division into rocky, icy, and gaseous classes.
In our solar system, three rocky planets had the potential early on for supporting life. Venus, Earth, and Mars were all endowed with carbon dioxide atmospheres, and at least Earth and Mars received large influxes of organic materials and water. The presence of a watery ocean was a key early step toward regulating and retaining the atmosphere. The absence or early demise of an ocean on Venus is causal to its present state: with no sink for carbon dioxide in the form of carbonates, all of the carbon dioxide remained as a massive atmosphere supporting a super-greenhouse warming: perpetually too hot to ever permit liquid water to exist.
- Type
- Chapter
- Information
- EarthEvolution of a Habitable World, pp. 299 - 300Publisher: Cambridge University PressPrint publication year: 2013