Context
The challenge
By signing the Paris Agreement, 195 States committed to taking measures to limit the global temperature increase to “as close to 1.5 degrees as possible”. Because according to climate models, the risk of entire systems – such as the Gulf Stream – reaching the tipping point increases significantly with greater warming of the Earth. However, the measures adopted to date will fall far short of this target.
Global greenhouse gas emissions and warming scenarios
Each pathway is subject to uncertainties, which are characterized by the range of low to high emissions in each scenario. Warming refers to the expected global temperature increase by 2100, relative to pre-industrial temperatures. Data source: CAT Climate Action Tracker, status 2019.
The main driver of global warming is the emission of greenhouse gases such as carbon dioxide (CO2), nitrogen dioxide (N2O) and methane (CH4), which change the temperature balance of the Earth. To halt the increase, we must not produce more greenhouse gases than nature can absorb (net zero). Currently, we are moving further and further away from this objective. Estimates show that humanity can emit a total of about 285 gigatonnes of CO2 and still meet the 1.5° target. At current emission levels, this budget will be used up in less than 7 years. This means that greenhouse gas emissions must now decrease very quickly and reach net zero as soon as possible.
Consequences of global warming
The consequences of increasing global warming are extremely far-reaching and affect all ecosystems and the whole of human civilization. The average temperature has already risen by 1° compared to 1850-1900 worldwide and by as much as 2° in Switzerland. The last few years were the warmest since weather records began. Warming is already causing an increase in droughts, large-scale fires and flooding worldwide. Models show that irreversible tipping points will be imminent if warming exceeds 1.5°.
Dangerous tipping points in the Earth’s climate
-
Melting of the polar ice caps:
Sea level rise threatens coastal region -
Greenland ice sheet melting:
Accelerating ice loss -
Loss of permafrost:
Landslides, destruction of infrastructures, methane emissions -
Dry zones, desertification:
Forest fires, agricultural yields reduced, migration -
Ocean currents weaken:
Gulf Stream could collapse -
Drying up of the Amazon:
Loss of CO2 sink, rain in South America fails to materialise -
Acidification of the oceans:
Die-off of corals, shells and fishes -
Antarctic ice melts:
Collapse of Antarctic habitat
Global vs. Swiss per capita emissions
Where greenhouse gases are produced in the world is irrelevant for the climate. However, emissions are anything but fairly distributed: per capita greenhouse gas emissions in India, for example, amount to about 1.6 tonnes per year, while in the USA the figure is almost 15 tonnes. Thus it is the wealthy, highly-industrialized countries that cause the lion’s share of emissions. Switzerland is also one of them. Although Switzerland’s domestic emissions are significantly lower than in other industrialized countries, if the emissions of all imported goods are added in, we end up with the same orders of magnitude. The poorest countries, which have no resources for adaptation measures, suffer most from the impacts of climate change.
Drivers of greenhouse gas emissions
Globally, we as humankind emit around 58 gigatonnes (Gt) of CO2 equivalents of greenhouse gases into the atmosphere per year. 42 Gt of these are CO2, the remaining 16 Gt are accounted for by other greenhouse gases. The most important emissions drivers are the burning of fossil fuels for heat and electricity, agriculture and forestry, industry and transport.
Drivers of global greenhouse gas emissions
Data source: IPCC, 2014: Climate change 2014: Synthesis report
In Switzerland, the distribution looks somewhat different, as electricity generation is relatively low in CO2 thanks to hydroelectric and nuclear power, the industrial sector is comparatively small and mobility is very high.
Greenhouse gas emissions in Switzerland
Data Source: Bundesamt fĂĽr Umwelt, Klima: Das Wichtigste in KĂĽrze
In Switzerland, the distribution looks somewhat different, as electricity generation is relatively low in CO2 thanks to hydroelectric and nuclear power, the industrial sector is comparatively small and mobility is very high.
It should be noted that these numbers only take into account the greenhouse gases that are emitted in Switzerland. Switzerland, as a small, economically highly-integrated country, imports a very large number of goods. As a result, more than half of the greenhouse gas emissions caused by our activities are not generated in Switzerland, but abroad. The official greenhouse gas emissions therefore reveal only half of the whole picture.