Industrialisation and the climate

• Increasing temperatures

  Rising temperatures as a trend over the past 135 years;

  Anomalies occurred between 1880 and 2014;

  2014 was the 38th consecutive year that annual global temperature rise was above average;

  Steep rise in temperatures in the 21st century; land temperature 1 degree above average and ocean temperatures 0.57 degrees above average.
• Rising sea level

  Since 1900 the average sea level rise has been 1.0 to 2.5 mm a year;

  Recent satellite data suggest a more rapid rate of 3 mm per year;

  Thermal expansion of the oceans and melting of land-based ice sheets and glaciers account for the rise.
• Increasing atmospheric water vapour


  Traps energy radiated from the Earth’s surface and creates the greenhouse effect;

  Water vapour is affected by temperature (warm air holds more) and rates of evaporation (Higher evaporation results in more atmospheric water vapour);

  Increasing temperatures lead to more atmospheric water vapour;

  For every 1 degree in temperature, rising levels of water vapour will double the warming.
• Shrinking valley glaciers and ice sheets

  Warming of the atmosphere melts ice;

  In the Alps valley glaciers may shrink by 80 to 96% by the end of the century;

  Ocean warming accelerates melting of ice sheets in coastal areas e.g. Larsen B ice shelf in Antarctica;

  Present-day melting of polar ice sheets adds approximately 1 mm to sea level every year.
• Increasing atmospheric water vapour
’s positive feedback effect.


  More water vapour; increased greenhouse effects; increased evaporation; increased levels of water vapour; more warming/increased greenhouse effect; more evaporation
• Decreasing snow cover and sea ice


  Measurements reveal a decline in spring snow cover of 2% per decade since 1966 in the Northern Hemisphere;

  Snow has an albedo effect, as it reflects 70 to 80% of incoming solar radiation;

  less snow cover means an increase in the absorption of solar radiation;

  as snow cover diminishes, the ground is warmed and air temperatures rise, which forms a positive feedback loop;
• How has anthropogenic greenhouse gas emissions increased?

  Continuing high dependency on fossil fuels;

  A steep rise in demand for electricity due to industrialisation and technological advances;

  Global population growth from 1 billion in 1800 to 7.4 billion in 2015;

  Land use change e.g. deforestation, drainage of wetlands and urbanisation.
• Change in anthropogenic emissions (1)

  Between 1850 and 1960, most GHG emissions came from the industrialised economies of North America and Europe.
• Change in anthropogenic emissions (2)

  Since the 1960s, emissions from Asia (particularly China) have increased significantly.

  Those of North America and Europe have stabilised and in some countries they have fallen e.g. Germany and the UK.
• Change in anthropogenic emissions (3)

  Global emissions are now uneven but heavily concentrated with the top ten countries accounting for almost 80% of emissions.

  The USA, Australia, Germany and the UK still account for the highest carbon dioxide emissions.
• Change in anthropogenic emissions (4)


  When emission of methane from land-use change is added as a GHG, Brazil and Indonesia enter the ranking in third and fourth place after China and the USA.
• Human influence the global mean energy balance. 1

  Atmosphere is the closed system; the system is stable when inputs of solar radiation equal outputs of terrestrial radiation.

  45% of incoming solar radiation reaches and warms the Earth’s surface (1/3 is reflected from clouds, 1/5 absorbed by water droplets, ozone, carbon dioxide and dust into the atmosphere, and a small amount is reflect from surfaces such as snow).
• Human influence the global mean energy balance 2

  Of the outgoing radiation, 2/3 are lost in space and the rest is absorbed by GHGs;

  GHGs play a crucial role in stabilising global temperatures.
• Human influence the global mean energy balance 3

  Human activity in the past 200 years has caused the global energy balance to be uneven;

  increasing amounts of GHGs absorb more terrestrial radiation; global temperatures have risen; rising temperatures increase evaporation and the amount of water vapour in the atmosphere; rising temperatures also melt snow and ice, reducing the reflection of incoming solar radiation.