The earth is a comfortable place for living things because of the greenhouse effect.
It maintains the right temperatures for humans, plants and animals to survive.
How does this greenhouse effect occur?
Similar to a greenhouse with glass walls and a glass roof used to house plants.
The clear glass allows sunlight to shine into the greenhouse, while also trapping the Sun's heat inside.
This is how a greenhouse keeps plants warm, even at night and in the winter.
The greenhouse effect keeps Earth warm in pretty much the same way.
Instead of glass, the earth is surrounded by gasses called the atmosphere.
In the daytime, the Sun shines through the atmosphere warming Earth's surface.
After the Sun goes down, Earth's surface cools.
This releases heat back into the air.
But, some of that heat is trapped by the gases in the atmosphere.
These heat-trapping gases are called greenhouse gases.
Carbon dioxide (CO2), water vapor and methane are all examples of greenhouse gases.
Earth needs a balance of greenhouse gases to maintain just the right temperature for living things.
But, some human activities are changing Earth's natural greenhouse effect.
For example, burning fossil fuels – like coal and oil – releases more carbon dioxide into our atmosphere.
Even farming practises of replacing forests with pastures and methane producing beef cattle.
These extra greenhouse gases can cause the atmosphere to trap more and more heat, leading to a warmer Earth.
How much CO2 is in the atmosphere?
A recent episode of ABC Lab Notes titled Why CO2 peaks at this time of year explained the amount of CO2 in the atmosphere-:
Pre-Industrial times 280 ppm now (2025) 420 ppm.
What is a Carbon Footprint?
A Carbon Footprint is the total amount of greenhouse gases (including carbon dioxide and methane) that are generated by our actions.
The average Carbon Footprint for a person in the United States is 14 tons, one of the highest rates in the world.
(Australia 15 tons - India 1.9 tons - UK 5 tons)
Globally, the average carbon footprint is closer to 4 tons.
To have the best chance of avoiding a 2º Celsius rise in global temperatures, the average global carbon footprint per year needs to drop to under 2 tons by 2050.
The average American or Australian produces the same amount of emissions in under two days as the average person in Mali or Niger does in an entire year.
No threat to farm land: just 1,200 square kilometres can fulfil Australia's solar and wind energy needs...
The area devoted to agriculture is about 3,500 times larger at 4.2 million square kilometres.
iceds.anu.edu.au
Getting to Net Zero
"Net zero by 2050" is a global goal under the Paris Agreement, aiming to balance greenhouse gas emissions produced and removed from the atmosphere, to limit global warming to 1.5°C–2°C.
There is a growing movement in several countries to challenge, delay, or dilute commitments to net zero emissions by 2050. This is not a unified global movement. It is mainly driven by political, economic, and ideological factors.
References and Sources
https://www.youtube.com/watch?v=SN5-DnOHQmE NASA
www.nature.org
https://www.worldometers.info/co2-emissions/
