Causes and Impacts of Climate Change

Causes of Climate Change

Climate change is driven by a mix of natural and human influences on the Earth’s climate system. These influences can be separated into two broad categories:

  • Natural factors
  • Human factors

Natural factors

Natural factorExplanation
Orbital changesNatural variations in the Earth’s orbit and tilt, known as Milankovitch cycles, can lead to long-term climate variations over thousands of years.
Volcanic activityVolcanic eruptions release greenhouse gases, including CO₂ and aerosols, into the atmosphere.

This process can influence short-term climate fluctuations.
Solar outputThe Sun’s energy output naturally fluctuates, influencing Earth’s temperature and climate patterns.

Human factors

Human factorExplanation
Use of fossil fuelsThe combustion of fossil fuels (coal, oil and natural gas) releases large amounts of CO₂ into the atmosphere.

This contributes to the greenhouse effect and global warming.
DeforestationClearing forests for agriculture or other purposes reduces Earth’s capacity to absorb CO₂ through photosynthesis.

This leads to higher levels of CO₂ in the atmosphere and increased global warming.
Farming practicesAgricultural activities, such as livestock farming, result in the release of methane (a potent greenhouse gas) through enteric fermentation and manure management.

Also, the use of fertilisers in farming can lead to the release of nitrous oxide (N₂O), another greenhouse gas.

Impacts of Climate Change

Climate change has far-reaching effects on both people and the environment. These impacts can be categorised as social, economic and environmental.

Social Impacts

  • Health – Increased temperatures and altered precipitation patterns can encourage the spread of diseases such as malaria and water-borne diseases, intensify heat waves, and degrade air quality, affecting people with respiratory and cardiopulmonary diseases.
  • Nutrition – Climate-related food shortages can lead to malnutrition and even famines. Also, changing agricultural conditions can impact the availability and diversity of crops.
  • Employment – Job losses due to climate change can lead to societal problems like increased rates of poverty or social unrest.
  • Displacement: Rising sea levels and more frequent severe storms can lead to coastal flooding and the displacement of communities.

Economic Impacts

  • Agriculture – Farmers may need to adapt to changing climate conditions, which can affect crop yields and agricultural productivity. For example, altered rainfall patterns could limit water availability, therefore affecting irrigation and reducing overall agricultural productivity.
  • Employment – Changes in climate can impact job opportunities in various sectors, including tourism, fishing and farming. This can have broader impacts on national or regional economies, such as reduced GDP or increased economic inequality.
  • Settlements – Low-lying areas at a higher risk of flooding may need to invest in costly measures such as improved flood defences or relocation.

Environmental Impacts

  • Sea Level Rise – Warmer temperatures cause seawater to expand and ice to melt, which contributes to rising sea levels. This can cause coastal erosion and threaten coastal ecosystems and communities.
  • Natural Hazards – Changes in climate patterns can increase the frequency and severity of storms, droughts and wildfires, leading to higher risks of flooding and property damage.
  • Ecosystem Change – As climate conditions change, the locations of different types of ecosystems (known as ‘biomes’) can shift. These shifts can threaten fragile ecosystems and biodiversity, including coral reefs, mangrove swamps and polar regions.