What is global warming? Chemistry Calendar, March: Climate & Energy


Sweden. A country with a climate consisting of four distinct seasons. And winter as we know it has always been pretty cold. But during our travels around the world we have experienced many different climates. Polar regions are cold, and near the equator it is warm. Rainforests are hot and humid, and deserts are hot and dry. But you have probably heard it all before, right? Climates around the world are changing, and global temperatures are going up. Even though a morning like this Global Warming feels a little hard to believe. Well, did you know that there are questions in almost every step of the Global Warming discussion, that could be answered through chemistry? No? Alright, let’s show you some examples. Earth’s atmosphere can be compared to a greenhouse. And the reason our planet has a climate we can live in is due to gases in the atmosphere called greenhouse gases. Does the name ring a bell? When we hear about them in the news it is sometimes in a negative way, but without them we wouldn’t survive.

Let me explain. The air in the atmosphere is composed mostly of two gases: nitrogen and oxygen. And together they make up more than 99% of the atmosphere. Out of the small percentage remaining, there are a few gases referred to as greenhouse gases. For example, carbon dioxide, methane and the most abundant one being water vapor. And together these gases are responsible for The Greenhouse Effect, a warming effect discovered by our first Swedish Nobel Laureate, Svante Arrhenius. But, to understand it more, we went to see Johan Boman, at the University of Gothenburg. Greenhouse gases, due to their molecular structure they absorb incoming radiation and to get rid of this extra energy they emit it as heat. Johan Boman tells us that the gases referred to as greenhouse gases all have more than two atoms in the molecules and when struck by certain radiation the molecules absorb the energy, starts to vibrate, and then emits that energy as heat in all directions. Some of it then goes back to Earth resulting in the warming Greenhouse Effect.

He also explains that since life on Earth is based on water, much of that water would freeze if it wasn’t for the Greenhouse Effect, and life as we know it wouldn’t exist. So we need the Greenhouse Effect. So whatever we do, don’t fight the Greenhouse Effect, but Global Warming, that’s may be something that we could try to mitigate and reduce. Well, scientists have discovered that Earth’s global temperature is increasing now to more than it has been for a long long time. But how can they know that? Alright, we’re on this frozen lake here in Sweden and we are going to take a closer look at the ice. Check this out. It doesn’t look exactly the same all the way through. And that is because the environmental conditions weren’t exactly the same when the different layers of the ice froze.  So what does this have to do with chemistry? Well, cores from glaciers are somewhat similar.

They are just much much bigger. You see, glacial ice doesn’t melt the way our lake eventually will. So by doing chemical analyses of samples of the ice at various depths we can track environmental conditions at different stages in history because the chemicals locked in the ice gives us a snapshot of what the environment was like at the time when that ice froze. One thing scientists have been able to tell from this is that global temperatures have gone up. Plus, by analyzing the gases in the ice scientists have also found that the amount of some greenhouse gases, like CO2 and methane have also increased. And this made them start to think that the two could be linked. Alright, so with Chemistry we’ve been able to track the history of greenhouse gases, but can chemistry also help us in the future, by limiting the amount of greenhouse gases we produce? Well, of course it can. Chemistry is also extremely important in diversifying our energy sources beyond only fossil fuels. And here’s an example.

You’ve seen solar panels before. But a lot of work is now looking at ways to more efficiently harvest the energy directly from the Sun. Just imagine if we could make these many times more efficient! Researchers are also trying to artificially mimic the way plants capture light, called photosynthesis. And, they’re also researching new ways to use plants and algae directly to produce biofuels. So we have seen even if it is hard to believe on cold days like this, that global temperatures are changing, but we may not always feel it. And we’ve also learned that greenhouse gases are important giving our Earth a nice warm climate, but they may now also play a part in changing the climate. So chemistry plays a role in pretty much every step of the global warming process, from explaining its source to finding new improved solutions for the future. Take care of our planet, and remember, even if you can’t always see it, Chemistry is all around You! .