Close this search box.
Close this search box.
Living Lightly column

Occam’s Razor

By Bruce Key, Wodonga Albury Towards Climate Health (WATCH)

Consider what’s happening in the northern hemisphere:

  • A few months ago, a town in Oman went for 51 hours without the temperature getting below 42.6 degrees Celsius, even at night.
  • The Arctic summer sea ice has reduced in volume by 70% since satellite monitoring began in 1979.
  • In most of southern and central Sweden, it was the warmest summer since records began, including in Uppsala (records began 1722), Stockholm (1756), Lund (1859) and Gothenburg (1860). In addition, there were serious wildfires which are rare in Sweden.
  • In Glacier National Park in the USA there are 25 glaciers today. In 1850 there were 150.  A similar decline is evident throughout the world.

Consider what’s happening in Australia:

  • In Victoria, the fire danger rating system was modified following ‘Black Saturday’ by introducing a new rating of ‘catastrophic’.
  • The inflows into Perth’s reservoirs averaged 338 gigalitres from 1911 until 1974, 177GL from 1975 to 2000 and about 80GL from 2001 to 2012. In 2016 the inflow was 12 GL.

And consider this:

  • If the average world temperature for each month in the 20th century is taken as the norm, then no-one younger than 33 has ever experienced even one month of below average temperatures.
  • Munich Re, the world’s largest insurer, has produced information which shows that the number of weather-related disasters has increased by 325% in 34 years. There has been no increase in the number of disasters caused by geophysical factors such as volcanos, earthquakes and tsunamis.

If we join these dot points, it seems that the climate is changing throughout the world. This is accepted by most people, but some don’t agree that the increase is caused by human activities.  This is where Occam’s Razor comes in. Occam’s razor is the problem-solving principle which states that the simplest solution tends to be the correct one.

John Tyndall showed experimentally in 1856 that carbon dioxide is a greenhouse gas that traps heat.  The amount of carbon dioxide in the atmosphere has increased by 43% in the past 100 years due to burning fossil fuels.  This appears to be the simplest explanation for the increasing temperatures, and in fact is the only explanation that scientists can find. If fossil fuels are changing the world, are we living lightly?