Climate change

Exercise 1

In terms of the climate’s history the last Ice Age began 2.6 million years ago and continues to this day. An Ice Age is divided into cold and warm periods, and currently we are in an interglacial period. The average temperature is 15 degrees Celsius. The Earth's temperature rose from 1906 to 2005 by 0.74 degrees Celsius and is as warm as been at any point in the last 1000 years. However, the temperature increase is not the same everywhere, so the continents are heating up faster than the oceans, for example, and the warming affects the polar regions most drastically.

"The CO2 emissions caused by man have quadrupled in the last 50 years. The ten warmest years in this period all fall in the last 15 years.“ Schwarzenbach, René/ Müller, Lars/ Rentsch, Christian/ Lanz, Klaus [HrsgIn] (2011): Mensch Klima! Wer bestimmt das Klima? Baden (CH): Lars Müller Publishers

NASA researchers have recently shown that the temperature rise in the air near the ground has halted for 15 years. Scientists had not predicted this development and so they cannot clearly explain it. Possible causes are the warming of the oceans, a dry expectant stratosphere, sulphur-containing gases and cold water flooding into the Pacific (La Niña). However, the influence of solar radiation and the influence of particles from industry, heating and car exhausts, oceans, volcanoes and the ground on the clouds and the water cycle are not well understood. These possible causes are thus only guesses and the uncertainties of climate forecasts are large. It will be interesting to see how the coming 2013/2014 fifth Assessment Report of the IPCC will address this pause in heating.

However, it is clear that with industrialization the concentration of greenhouse gases in the atmosphere has increased. There are about 30 greenhouse gases and the natural greenhouse effect has been increasing due to the greenhouse gases released by humans. For example, the CO2 level has increased in the last 160 years by 40% and the methane concentration more than doubled. But which greenhouse gases play an important role in the climate debate?

Task

Try to allocate the different gases to the pie chart.

It is also interesting that the different gases trap heat energy with different efficiencies, for example, methane contributes to global warming about 20 times and nitrous oxide approximately 300 times more potently than CO2. Moreover, the different gases remain in the atmosphere for long. But how long exactly?

Try to match the different lifetimes to the gases:

Now it remains to be clarified, which activities release the man-made greenhouse gases. Match the different sources of emissions of greenhouse gases to the pie chart: once all the terms are in the right place, you will see the exact percentage contributions.

Note

Peat is organic sediment that occurs in bogs and in its dried state it is flammable. Peat fires are therefore underground fires. Usually, these happen where the groundwater is artificially lowered and no rain or forest fires occur. The chance of peat fires starting is increased by high air temperatures, low humidity and wind.

Sources

www.ipcc.ch
www.spiegel.de
www.unep.org
www.epa.gov
www.wikipedia.org
Schüppel, Katrin (2007): Klimawandel und Klimaschutz. Informationen, Hintergründe, Diskussionsanregungen. Mülheim/Ruhr: Verl. an der Ruhr
Dow, Kirstin/ Downing, Thomas E. (2007): Weltatlas des Klimawandels. Karten und Fakten zur globalen Erwärmung. Hamburg: Europäische Verlagsanstalt