Sts g7

• Climate change refers to the long-term shifts in temperature and weather patterns as the result of nature or human activity
• Climate change

  Long-term shifts in temperature and weather patterns
• Global warming

  The upward trend of the Earth's temperature since the 20th century
• The Earth's temperature is the highest it has ever been compared to the past 100,000 years
• Consequences of climate change

  • Severe drought
  • Water scarcity
  • Rising sea levels
  • Heavy flooding
  • Catastrophic natural disasters
  • Declining biodiversity
• It is crucial we understand the causes of climate change and how we can lessen its effects
• NATURAL FACTORS contributing to climate change

  • Solar radiation and orbital variations
  • Volcanic eruptions and natural greenhouse gas emissions
• Solar radiation

  Energy produced by the Sun, some of which reaches the Earth
• The Sun is the source of energy that drives Earth’s climate system
• Solar radiation warms the atmosphere and produces global wind patterns
• Orbital variations


  • Seasonal distribution of sunlight
  • Global dispersion influenced by Earth's motion
• The beginning and end of ice ages are examples of climate changes brought on by oscillations and shifts in the Earth's orbit
• Types of kinematic changes

  • Variations in Earth's eccentricity
  • Changes in the angle of Earth's axis of rotation
  • Precession of Earth's axis
• Milankovitch's cycles


  Periodic changes in the orbital characteristics of a planet that control how much sunlight it receives
• Ways the Earth's orbit around the Sun changes

  • Eccentricity
  • Obliquity (axial tilt)
  • Precession
• Eccentricity


  Difference in shape between ellipse and a perfect circle
• With periods between 90,000 and 100,000 years, the Earth's orbit can be nearly circular, elliptical, or eccentric
• Obliquity

  Angle Earth’s axis of rotation is tilted as it travels around the Sun
• Obliquity causes one pole to be directed more toward the Sun on one side of the orbit and the other pole on the other side
• Changes in the tilt of the Earth can lead to small but climatically important changes in the strength of the seasons
• Precession


  A gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis
• Precession changes perihelion and aphelion dates, increasing or decreasing seasonal contrast in one hemisphere
• The current Earth's warming is not being caused by volcanoes
• Volcanic eruptions


  Release greenhouse gases such as carbon dioxide (CO2)
• Emissions from volcanoes since 1750 are thought to be at least 100 times smaller than those from fossil fuel burning
• Cooling effect of volcanic eruptions

  • Release of greenhouse gases
  • Sulphur dioxide can produce a cooling effect
• Explosivity

  Volcanic eruptions are rated from zero to eight on a scale of explosivity
• The characteristics of the ash cloud largely determine whether a volcanic eruption influences the climate or not
• Volcanic eruptions that reach the stratosphere can cause aerosol particles to remain in the atmosphere for years
• Volcanic eruptions may have an impact on the location of the Intertropical Convergence Zone (ITCZ)
• Greenhouse gas

  Absorbs the sun’s heat that radiates from the Earth’s surface
• The greenhouse effect keeps the Earth’s temperature warmer than it would otherwise be
• Human activity plays a role in the production of greenhouse gases
• Types of greenhouse gases

  • Fluorinated greenhouse gases
  • Carbon Dioxide
  • Methane
  • Nitrogen
• Fluorinated greenhouse gases (F-gases)

  Man-made gases with high global warming potential
• Methane


  A colorless gas primarily produced from various sources including livestock and agricultural practices
• Nitrogen


  Produced through soil microbial action and various human activities
• 3.6 billion tons of CO2 equivalent were produced by EU economic activity in 2021
• Methane accounted for almost 12% of all greenhouse gas emissions in the EU in 2021
• CO2 made up nearly 80% of the total greenhouse gas emissions in the EU