Long Night of Open Museums Zurich 2017
This year the long night of open museums at focusTerra, the museum of the Earth science department at ETH Zurich, was devoted to polar research and climate change.
The current special exhibition at the museum shows first insights of a newly launched expedition to Antarctica in 2016/2017. Although the expedition is organized by the Swiss Polar Institute it focuses on international and interdisciplinary collaborations wherefore scientists from all over the world are asked to take part in it. Because the polar ecosystems are very sensitive to climate change scientists have conducted lots of research on permafrost, glaciers and ocean chemistry to understand better how the polar regions are affected by global warming and climate change. They also try to understand which role these regions could play in the future for the Earth’s climate.
Therefore, the theme of this years workshops and experiments performed during the long night of open museums in Zurich, was all about bringing arctic research to the visitors.
The experiments I supervised were called “Flaschengeist” (genie in the bottle) because it looks as if ghosts want to escape the bottle. It was all about explaining how CO2 and other greenhouse gases like methane can escape when permafrost soil starts melting. To emphasize how easily CO2 is produced and that it is possible to capture it the children could do a hand-on experiment where they mixed baking powder with vinegar inside a bottle and then quickly covered its opening with a balloon. The reaction of baking powder or natron (NaHCO3) with an acid (in our case vinegar) leads to free CO2:
NaHCO3 + C2H4O2 —> CH3COONa + 2H2O + CO2
Starting from these artificial sources of CO2 I explained that in a similar way CO2 is released when permafrost starts thawing.
For that I had to start in the very beginning and asked the children what they know about climate change and if they knew about the greenhouse effect. Most kids had at least heard about it and others could even explain what the greenhouse effect is. One can image the Earth as a gigantic greenhouse which warms because of the radiation coming from the sun. Some incoming radiation is directly reflected by the atmosphere, clouds (water vapor) and the Earth’s surface. The rest is absorbed by the Earth’s ground and converted into heat. This causes the emission of longer wavelength (infrared) radiation. Some of this outgoing infrared radiation directly passes through the atmosphere to outer space, some heat remains in the ground and some of the longer wavelength radiation is reflected back by the so-called greenhouse gases (e.g. CO2 and methane CH4). Although most of the greenhouse effect is cause by water vapor, the additional back-reflection due to these gases which especially reflec
t the long wavelength radiation leads to an additional warming of the Earth which causes the human-made climate warming. I asked the kids what everybody can do to reduce their own carbon footprint. Together we thought of solutions: taking the bike, try to recycle as much as possible and eat locally produced food.
Then I went on and explained what Permafrost is: ground (soil, rock including ice) which has been frozen for at least two years in a row. It is usually overlain by an active layer, which thaws during summer and freezes once the temperature drops to 0° C and below. The thickness of the Permafrost can extend as far down as 1400m until the soil and rock is warmer than 0°C because of the heat of the Earth which increases with depth4,5. Permafrost mainly occurs in the North of the Northern hemisphere for example in Siberia, in the North of Norway, Finland and Sweden. There is also permafrost in lower latitudes but at higher altitudes, for example in the Alps. Researchers have estimated that Permafrost contains about 50% of the global soil carbon1.Thus, once it thaws it can release a great amount of this carbon in form of methane or CO2 2,3 which leads to a positive climate feedback. Recently, the role of microbes living in Permafrost has been again emphasized6. Certain microbes that are very prominent in some regions of Permafrost use the existing carbon and CO2 to live and outgas methane, a greenhouse gas that is much worse than CO2 itself. So, the more it warms, the more Permafrost thaws, the more greenhouse gases are emitted which leads to even more warming (and this is only one effect of global warming and resulting positive feedback loop).
Therefore, it is very important to be aware of climate warming, try to live a sustainable life style and spread the word!
If you are interested check out this video on youtube:
https://www.youtube.com/watch?v=lxixy1u8GjY
1 Tarnocai, C. et al. Soil organic carbon pools in the northern circumpolar permafrost region. Glob. Biogeochem. Cycles 23, GB2023 (2009)
2 Schuur, E. A. G. et al. Expert assessment of vulnerability of permafrost carbon to climate change. Clim. Change 119, 359–374 (2013)
3 Ciais, P. et al. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge University Press, 2013)
4 https://ipa.arcticportal.org/publications/occasional-publications/what-is-permafrost
5 https://en.wikipedia.org/wiki/Permafrost
6 McCalley, Carmody K., et al. “Methane dynamics regulated by microbial community response to permafrost thaw.” Nature 514.7523 (2014): 478-481.
Written by Jana Schierjott
