UNDERSTANDING CLIMATE CHANGE FROM A CHEMICAL POINT OF VIEW
Shrinking glaciers, thawing permafrost, increasing ocean temperature and rising sea levels. The term climate change is widespread. News reports are full of the effects of the rising global temperature and we hear about it in many public discussions. The movement Fridays for Future has raised awareness among the youth all over Europe about this complicated and polarizing topic. Thousands of students protested every Friday to get heard by the politicians, and it worked! Every political party (at least in Germany) has an opinion or a plan on how to deal with climate change. In other countries the topic is still discussed as it is not a fact but a question of faith. But what exactly is climate change and what do we have to do with it?
Little disclosure: I am not a scientist and this is just a very basic explanation. If you want to find out more, you can check this website: https://www.metoffice.gov.uk/weather/climate-change/what-is-climate-change
Putting the greenhouse effect in a nutshell
Our atmosphere is full of gas. Most of it is nitrogen and oxygen, but there are also the so-called trace gases like carbon dioxide, methane, ozone, chlorofluorocarbons and water vapour.
As is well-known, methane, water vapor and CO2 are the most important greenhouse gases. But what does that mean? The sun releases tons of energy through nuclear fusion in its core every second. Part of this energy hits the earth in the form of light. The earth absorbs this energy and reflects parts of it back into space in the form of heat, i.e. infrared radiation. For this to happen, however, it must first pass through our atmosphere.
To understand why this doesn’t happen completely, we need to look at the structure of, for example, CO2. CO2 is a planar molecule. Two double bonds connect the two oxygen atoms to the carbon atom. When infrared radiation strikes this molecule, certain wavelengths succeed in vibrating the bonds between the carbon and the oxygen molecules (this phenomenon is also used in IR spectroscopy).
To put it in physical terms: thermal energy is converted into kinetic energy. However, this condition does not last forever. At some point the molecule stops vibrating and converts the kinetic energy back into thermal energy. But this released heat is emitted in all directions and not just on the side facing away from the earth. This is how part of the heat returns to the earth.
In itself, the greenhouse effect is not a bad thing. Without it, the temperature on earth would be below freezing and we need carbon dioxide in the atmosphere so that plants can photosynthesise and water vapour so that it can rain. It becomes problematic the moment humans release more greenhouse gases. The more greenhouse gases there are in the atmosphere, the more heat radiation is reflected back onto the earth. So the temperature rises the more greenhouse gases we release. As a result, we shift an infinite number of equilibrium reactions in our atmosphere, which we cannot keep track of, and sooner or later make the planet uninhabitable for us humans.
Climate protection in chemistry, or why you should study chemistry
Climate change concerns and affects all of us. However, it doesn’t help our planet much if we only complain and demonstrate about politics. We need to act and find other options and ways to ensure the world’s energy supply. Proposed solutions are needed! It is irrational to think that all people suddenly stop driving cars or flying planes, lignite is no longer mined and people altogether refrain from using electricity. We need to be one step ahead in our development and not step back. And there are many ways to work as a chemist on climate protection.
On the one hand, you can get involved in saving resources and avoiding waste. New insulation materials are required; light-emitting diodes, such as OLEDs have to be developed further; new quantum materials can make electronics less glossy; large environmental processes such as aluminum production have to be converted, and batteries for hybrid and electric vehicles have to be developed. More effective detergents would save water and electricity.
On the other hand, new energy sources have to be developed. Research areas still open or in need of improvement would be:
- catalysts for the production of bio-fuels
- fuel cells
- photo-chemical water splitting with sunlight
- photovoltaic systems
As you can see there are many areas in chemistry that could be improved with your help. It is always better to take active action against dangers than just to fear it or to negate it generally, so if you are interested in the continued existence of the earth as a habitat and you are interested in chemistry, study this subject. Study chemistry and solve one problem at a time, ultimately eliminating the danger of climate change altogether.