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Pre-industrial reference period

Human-induced, global warming is calculated by comparing pre-industrial with today's temperature measurements. In order to assess temperature evolution in Switzerland in the context of global warming the definition of a pre-industrial reference period for Switzerland is necessary.

In the Paris Agreement on climate change from 2015 the international community has set itself the goal of limiting human-induced, global warming to well below 2°C compared to pre-industrial levels. This measure allows to advert the worst consequences of climate change. Global temperature records show that global warming has reached +0.8°C (as at 2018) compared to pre-industrial levels. However, different regions of the world have warmed to different degrees. What about Switzerland?

In the following video you can see how temperature change in Switzerland can be compared to the global evolution and where Switzerland stands today in this comparison. Let us explain how future temperature development might look like and how our decisions affect future climate in Switzerland.

The most important points at a glance

The Paris Agreement on climate change

  • Agreement of the international community on the reduction of global greenhouse gas emissions with the goal to limit global warming to well below 2°C compared to pre-industrial levels.
  • In the global context pre-industrial temperature conditions are described using the mean temperature of the period 1850 to 1900. Human-induced warming cannot be seen yet during that time and the mean temperature of the period was not abnormally influenced by natural factors such as solar activity or volcanic eruptions.

Pre-industrial reference period for Switzerland

  • For Switzerland the period 1871 to 1900 is used as pre-industrial reference period because comprehensive measurement data are only available from 1864 onwards.
  • The temperature difference between 1871-1900 and the globally used period 1850-1900 is very small in Switzerland and has no effect on the measured warming.
  • Compared to the mean temperature of pre-industrial levels Switzerland has warmed by almost 2°C until today. This is more than twice the average global warming of 0.8°C (as of 2018).

Combining the past and future

  • The CH2018 climate change scenarios show how temperature in Switzerland will change in the 21st century compared to the reference period 1981-2010 as a function of future global greenhouse gas emissions.
  • By introducing a pre-industrial reference period for Switzerland, these future scenarios can be combined with the past.
  • Without climate change mitigation, the average annual temperature of Switzerland will rise around 6°C by the end of the 21st century compared to pre-industrial levels. Concerted climate change mitigation measures can limit warming in Switzerland to around 2.5°C.