Climate Change Notes

Climate Change

  • Climate change is a long-term shift in Earth's climate, typically over decades, leading to weather changes.
  • Global warming is the increase in Earth's average surface temperature due to greenhouse gases.
  • Temperatures have risen globally by approximately 0.8°C0.8°C over the last 100 years, with Europe warming faster (by 1.3°C1.3°C in the twentieth century).
  • Rising global temperatures can be dangerous to the balance of nature.

Surface Reflectivity

  • Lighter-colored objects (e.g., snow, ice, clouds) reflect more heat energy back into space, helping Earth remain cool.
  • Darker-colored objects (e.g., oceans, forests, soil) absorb more heat from the Sun, warming up Earth.
  • Earth usually absorbs around 70% of sunlight and reflects 30%; melting ice and snow due to global warming can disrupt this balance.

Global Dimming

  • Burning fossil fuels releases particles (soot, ash) into the air, which allows water vapor to gather and create larger clouds.
  • Polluted clouds contain more water and act like mirrors, reflecting more sunlight back into space (global dimming).
  • Global dimming can lead to colder water temperatures and decreased rainfall, potentially causing drought.

Oceans and Climate

  • Oceans trap heat energy from the Sun and distribute it around Earth via currents, maintaining heat transfer.
  • Oceans absorb approximately 40% of the carbon dioxide released into the atmosphere.
  • CO₂ is an acidic gas; when dissolved in water, it makes the water more acidic, affecting marine life.
  • Oceans are also absorbing 90% of the excess heat generated by increased greenhouse gases.
  • Warmer water absorbs less CO₂, which can cause more heat to stay in the atmosphere and further warm the planet.
  • There are sections of the North Atlantic that are currently unable to absorb as much CO₂ as they used to.

Carbon Dioxide

  • There has been a 40% increase in the level of carbon dioxide concentration in the atmosphere since the Industrial Revolution in the late 1700s, according to NASA scientists.
  • Excess carbon dioxide is causing the worldwide climate to change.

Factors of Climate Change

  • Oceans: Absorb heat/CO2, distribute heat via currents.
  • Surface Reflectivity: Reflection of sunlight by surfaces.
  • Global Dimming: Reflection of sunlight by polluted clouds.

Greenhouse Effect

  • The greenhouse effect occurs when gases in Earth's atmosphere prevent some of the heat from escaping into space.
  • Greenhouse gases trap heat in the atmosphere, making Earth warmer.
  • Main greenhouse gases: Carbon dioxide CO<em>2CO<em>2, methane CH</em>4CH</em>4, nitrous oxide N<em>2ON<em>2O, and water vapor H</em>2OH</em>2O.
  • Increased burning of fossil fuels has disrupted the balance of carbon dioxide, resulting in global warming and climate changes.