What are greenhouse gases?

Ruairi

You might have heard that climate change is caused by greenhouse gases, but what exactly are greenhouse gases?

Greenhouse gases refers to a number of chemicals in the earth’s atmosphere, carbon dioxide, methane, nitrous oxide, and industrial ones like fluorinated or F-gases.

If they’re allowed to build up too much, we see changes in the Earth’s average temperature, known as climate change.

Greenhouse gases come from lots of different sources. Carbon dioxide is released from burning fossil fuels. Methane is ‘released’ from farm animals…moving on! And nitrous oxide is released from fertilizers and cow manure.

Fluorinated gases are manufactured and used in refrigeration and air conditioning.

Over millions of years, the earth’s atmosphere has been able to trap “just” the right amount of heat for life on Earth to thrive. But too many of these Greenhouse gases are being added to the earth’s atmosphere, and because they absorb more heat from the sun they are making the earth hotter, like a greenhouse.

The more greenhouse gases there are in the atmosphere, the hotter the Earth gets leading to things like – changes in weather patterns, higher sea levels, drought, fires and floods.

Carbon dioxide has caused the most global warming because there is more of it and it hangs around for a very long time.

However, per tonne Methane has a stronger warming effect nearly 30 times stronger than carbon dioxide. Nitrous oxide is over 250 times stronger than carbon dioxide and F-gases are over 1000 times stronger!

Since the industrial revolution, huge amounts of these gases have been released into the atmosphere, warming our planet by 1.1°C. I know that doesn’t seem like much, but it has already caused irreversible damage to people and nature.

We now have the highest level of global greenhouse gases in our atmosphere, more than any other time in human history.

Scientists warn that we must urgently reduce the production of greenhouse gases to limit more global temperature rises. To do this we need to be less reliant on fossil fuels and switch to renewable energy sources for electricity and transport.

We can also consider the choices we make surrounding food, like eating more plant-based meals, looking at how far our food has travelled and introducing more sustainable farming methods.

Globally, laws can be made to protect the Earth’s natural defences or ‘Carbon Sinks’ like forests, peatlands, soils and waterways which can absorb the most harmful greenhouse gases out of the earth’s atmosphere.

Out of all the greenhouse gases, carbon dioxide will cause the most warming if we don’t reduce levels now. However, the power of the other greenhouse gases means that any reductions of these will give us a huge boost towards reducing global warming.