Introduction to greenhouse gases, industry and climate change

Now, you’ll be shown case studies about greenhouse gases, industry and climate change.

Note: Remember that if this is one of the topics you want to focus on, you should be working in more depth, and perhaps even doing some further reading or research into this topic in your own local area. If this isn’t a topic you are focusing on, make sure you spend a little less time on each case study. Once you are familiar with the case study, and the main idea of what they are doing, you can mark the step as complete, and continue.

A brief introduction to climate change

A ‘greenhouse gas’ is a gaseous compound with the ability to trap heat (or longwave radiation) in the Earth’s atmosphere.

On a very simple level, the ‘greenhouse gas effect’ is the name for the process where certain gases trap heat in Earth’s atmosphere and contribute to the warming of the planet as a whole.

Diagram of how greenhouse gases affect the Earth's atmosphere

As you can see from the diagram, the sun’s rays (electromagnetic radiation with varying wavelengths) travel from the sun and pass through the Earth’s atmosphere. The Earth then absorbs the radiation with short wavelengths, causing it to warm up. Some of the radiation that would have left Earth’s atmosphere is instead absorbed by greenhouse gases, causing the atmosphere to warm up even further. In short, the presence of greenhouse gases means more radiation is trapped in the atmosphere, making the Earth warmer than if they were not present, and thus contributing to global warming.

If asked to name a greenhouse gas, many of us would say ‘carbon dioxide’, ‘methane’ or ‘nitrous oxide’. Although these three are the most abundant in our atmosphere, the lesser known tetrafluoromethane (CF4) is harming our atmosphere and increasing global warming 7,360 times more than CO2! (See, for example, Mühle et al., 2010, or Montzka, et al., 2011.) In fact, CF4 is among the most potent greenhouse gases (GHGs) currently regulated under the Kyoto Protocol of the United Nations Framework Convention of Climate Change (UNFCCC).

Semiconductor chip

A Semiconductor Chip

CF4 is emitted into the atmosphere by three main industries:

  • the aluminium industry;
  • the semiconductor industry;
  • rare earth smelting.

CF4 has a half-life of 50,000 years, so even 50,000 years from now, all we can hope for is that only half of it will be in the air, as there is nothing at all that can suck it out of the atmosphere.

Over the period of 1990 to 2017, aluminium production has risen from 20,000 Ktonnes to approximately 60,000 Ktonnes. This could be due to economic growth, global and local financial crises or political instability. Rare earth smelting has also been on the rise and although the semiconductor industry is fairly new, only having been created in 1947, it has seen a huge growth in sales in the 1990s onwards, driven by the boom in personal electronic devices. Although the rise in productivity is positive in economic terms, the effect of extra CF4 being emitted into the environment could be very harmful.

So what’s being done?

The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on Climate Change (UNFCC). Countries that have agreed to the protocol are tied to internationally binding targets towards reducing the levels of greenhouse gases in the atmosphere. Due to the high levels of GHG emissions being mainly a result of more than 150 years of industrial activity, it is recognised that developed countries should be held more responsible and so should be under more pressure to reduce emissions. At the moment, each country creates an estimate of their emissions and submits that to the UNFCC. However, it’s thought that previous estimates haven’t been the most reliable, and haven’t taken into account the shift in the aluminium and semiconductor industries, nor the rise of rare earth smelting.

So what else is being done?

During the next few steps, you’ll hear from experts in the field of greenhouse gases, industry and climate change. Afterwards, you’ll have the chance to get involved with a discussion around the roles each person has taken in reducing the effects industry has on the environment around us.

Montzka, S., Dlugokencky, E., and Butler, J. (2011). ‘Non-CO2 greenhouse gases and climate change’, Nature Vol 476, Issue 7358, 43–50
Mühle, J., Ganesan, A. L., Miller, B. R., Salameh, P. K., Harth, C. M., Greally, B. R., Rigby, M., Porter, L. W., Steele, L. P., Trudinger, C. M., Krummel, P. B., O’Doherty, S., Fraser, P. J., Simmonds, P. G., Prinn, R. G., and Weiss, R. F. (2010). ‘Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane’, Atmospheric Chemistry and Physics, Volume 10, 5145–5164. Full text available open access.
United Nations Framework Convention on Climate Change (UNFCC). (1992). ‘United Nations Framework Convention on Climate Change: Consolidated text including amendments’

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This article is from the free online course:

Unleash Your Potential: Sustainable Futures

University of Bristol