We have been talking about greenhouse gases for decades but did we really understand their role in climate change?
What is it?
A greenhouse gas, is a gas in the atmosphere that absorbs and emits radiation. The primary greenhouse gases in earth´s atmosphere are: water vapour, carbon dioxide, methane, nitrous oxide and ozone.
Without these gases we would freeze all year round.
Nope, no beaches, no summer holidays, no good food. The world would be quite different, do not you think?
So, well, greenhouse gases naturally occur in our planet.
Thank god they do, otherwise we would live in permanent Siberian winter. And actually I like the way our lovely planet work now, I like the seasons, water and the possibility of finding and growing food, that so far I know is still quite relevant for our survival. Isn´t it?
But as we already know, most greenhouse gases have both natural and human-caused sources. During the pre-industrial Holocene, concentrations of existing gases were roughly constant. In the industrial era, human activities have added greenhouse gases to the atmosphere, mainly through the burning of fossil fuels and deforestation practices.
Since the beginning of the Industrial Revolution, the concentrations of most of the greenhouse gases have increased.
it is definitely not because you did a BBQ two years ago.
But please avoid having a BBQ national day, that would be a catastrophe.
Our economy is based on fossil fuel, whatever we want to extract, produce and deliver.
We keep producing mass products which most of them are not even really useful for humanity and the environment.
We clear forests for livestock farming, for cutting wood, convert them into parking spots maybe, building cities which are not ecologically planned and for mass agricultural production purposes. We increase the need and farms of ruminants especially cows which consistently contribute to methane emissions with their digestive process. And we use fertilizers, that lead to higher nitrous oxide (N 2O) concentrations.
But why do we do that?
Carbon dioxide in Earth’s atmosphere
if half of global-warming emissions are not absorbed.
(NASA simulation; 9 November 2015)
It looks like people from the northern hemisphere might be accountable.
Nitrogen dioxide 2014 – global air quality levels
(released 14 December 2015).
I probably need to move up to the mountains or somewhere on an island.
This increment in emissions significantly contribute to the greenhouse gas effect and therefore to Climate change.
But why does it?
Now that we know what greenhouse gas means and where do we find it in nature we understand that since the advent of agriculture but especially since the industrial revolution we interfered with the natural and delicate cycle of carbon cycling through the atmosphere , the ocean, plants, land and carbon sequestration.
It is a delicate cycle which took quite some time to get stable, most probably thanks to the advent of plants which sequestered CO2 fostering life diversity and surprise surprise, us.
Some solar radiation is reflected by earth and the atmosphere but some radiations is absorbed by earth´s surface and trapped by greenhouse gases keeping the earth warm.
So why is something changing in this cycle?
Because we burn fossil fuels (as well as incrementing water vapour emissions) at an unprecedented speed rate and we cut down forests (which sequester CO2) for exploiting natural resources or for livestock farming.
The sun´s ultra -violet energy (heat) pass through the upper atmosphere. This UV energy is reflected from the ground as infrared energy which is then trapped by the CO2 inducing the planet to heat up.
Watch this video to better understand the Greenhouse effect.