Comparing the Impact of Man-Made and Natural Green House Gas Emissions

I have grown up hearing about climate change and greenhouse gases (GHGs) and how they have a negative impact on our environment and planet.

I have also learnt that the planet itself produces these same gases.

So I pose the question, if the planet, for millions of years, produced carbon dioxide, methane etc, and managed to maintain an environmental equilibrium, then is it bad if humans produce the same gases?

The answer is yes.

Natural GHG production

An example of a natural GHG source is volcanoes.

Volcanoes are known to erupt and spew all kinds of material into the environment such as lava and gases. These natural environmental phenomena have been occurring almost as long as the Earth has existed.

In modern society, due to their destructive behaviour, we have deemed volcanic eruptions to be dangerous and hazardous to the environment. In the short term, yes, the eruptions do cause negative change to the surrounding environment but nature has always bounced back, with plants and wildlife always regrowing and reforming in the affected areas.

Man-made GHG sources

Now onto man-made GHG sources. Roughly from the birth of the industrial revolution, humans have been producing excess carbon dioxide and other environmentally harmful gases and releasing them into the atmosphere and environment.

How bad can man-made GHG contributions be, if natural GHG sources are not detrimental to the environment?

According to a paper published in Advances in Climate Change Research, man-made emissions account for approximately 55.46% of the total global GHGs emissions (2016 value), i.e. man-made emissions are equal to roughly 125% of natural emissions (humans produce more GHGs than nature).

As long as the Earth is able to still absorb this extra amount of emissions then the global system would still be in equilibrium, right?

Well, it was also found that the amount of GHG emissions that the Earth can absorb is roughly the same amount that is naturally produced. Therefore the GHG emissions generated by human activity put extra pressure on what is otherwise a self-balancing Earth[1].

To summarise, the Earth is being put under pressure due to man-made GHGs. Therefore, it is essential that we aim to reduce our own GHG emissions to help lighten the burden on our planet.

References:

[1] - Xi-Liu YUE, Qing-Xian GAO, Contributions of natural systems and human activity to greenhouse gas emissions, Advances in Climate Change Research, Volume 9, Issue 4, 2018, Pages 243-252