Climate & the Natural Greenhouse Effect (Cambridge International IGCSE Environmental Management)

What is climate?

• Climate refers to the average weather conditions in a specific area over a long period of time, typically 30 years or more

  • It includes patterns of temperature, humidity, and precipitation

• The climate is influenced by various factors, such as:

  • Solar radiation
  • Atmospheric circulation patterns
  • Ocean currents
  • Land features
  • Greenhouse gas concentrations

• The global climate conditions of the Earth have changed over time, leading to colder and warmer periods

• The last 2.6 million years are the Quaternary period, when there have been 60 cold periods and warmer interglacial periods

• The last ice age ended approximately 25,000 years ago

What is the natural greenhouse effect?

• The greenhouse effect is a naturally occurring phenomenon where solar radiation passes through the atmosphere to the Earth's surface

• Some of this energy is absorbed by the land and oceans, heating the Earth

• Some solar energy is reflected back into space

• The remaining solar energy is absorbed by the greenhouse gases and clouds and then re-emitted in all directions back to Earth, causing the temperature of the surface to rise

• This process is important to ensure that Earth is warm enough for life

• Without the greenhouse effect, the average temperature would be much colder, making the planet uninhabitable

  • For example, the average surface temperature of Earth is about 15 °C
  • Without the greenhouse effect, it would be about -18 °C

Natural greenhouse effect

Exam Hint Remember that weather is what you get on a day-to-day basis; climate is the conditions you expect a place to have. You expect the UK to be fairly cool and wet, Singapore to be warm and humid, and Egypt to be hot and dry.