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Biology LibreTexts

9: Climate

  • Page ID
    32527
    • 9.1: Climate and Weather
    • 9.2: Atmosphere and Climate Regulation
      About 3.5 billion years ago, early life forms (principally cyanobacteria) helped create an oxygenated atmosphere through photosynthesis, taking up carbon dioxide from the atmosphere and releasing oxygen. Over time, these organisms altered the composition of the atmosphere, increasing oxygen levels, and paved the way for organisms that use oxygen as an energy source (aerobic respiration), forming an atmosphere similar to that existing today.
    • 9.3: Causes of Global Climate Change
    • 9.4: Evidence of Global Climate Change
    • 9.5: Anthropogenic Causes of Climate Change
      As shown in the previous section, prehistoric changes in climate have been very slow. Climate changes typically occur slowly over many millions of years. The climate changes observed today are rapid and largely human-caused. Evidence shows that climate is changing, but what is causing that change? Scientists have suspected since the late 1800s that human-produced (anthropogenic) changes in atmospheric greenhouse gases would likely cause climate change.
    • 9.6: Past and Present Effects of Climate Change
    • 9.7: Implications of Climate Change
    • 9.8: Climate Change
      Earth’s temperature depends on the balance between energy entering and leaving the planet. When incoming energy from the sun is absorbed, Earth warms. When the sun’s energy is reflected back into space, Earth avoids warming. When energy is released from Earth into space, the planet cools. Many factors, both natural and human, can cause changes in Earth’s energy balance.
    • 9.9: Climate and the Effects of Global Climate Change
      All biomes are universally affected by global conditions, such as climate, that ultimately shape each biome’s environment. Scientists who study climate have noted a series of marked changes that have gradually become increasingly evident during the last sixty years. Global climate change is the term used to describe altered global weather patterns, including a worldwide increase in temperature, due largely to rising levels of atmospheric carbon dioxide.