Heat in, heat trapped
The sun heats the Earth. The Earth sends that heat back toward space. Some gases in the air absorb part of that outgoing heat and hold it close, like a wrapper holding warmth around suya. That trapping is the greenhouse effect.
The effect itself is not the problem. Without it, the planet would be frozen. The problem is the dose. Burning coal, oil and gas adds carbon dioxide to the air far faster than nature removes it. More gas, more trapped heat.
How we know this is real
This is not a theory fighting for attention. Scientists measured the heat-trapping power of carbon dioxide in the 1800s, before Nigeria was even one country. Since 1958, a station in Hawaii has recorded CO2 rising year after year. Ice cores let us check the air from hundreds of thousands of years ago.
Before factories, the air held about 280 CO2 molecules per million. Today it holds over 425. You can check every one of these numbers yourself. That is the standard this course holds: nothing you can't verify.
Why one degree matters
The planet has warmed by roughly 1.3 degrees Celsius on average since the late 1800s. One degree sounds small. It is not. It is an average over the whole planet, oceans included, all year round.
A small shift in the average means a big shift in the extremes. Hot days come more often and hit harder. Rain arrives in heavier bursts. For a coastal city like Lagos, the extremes are the story. The average is just the engine behind them.
Hold on to these
- Greenhouse gases trap outgoing heat. More gas means more trapped heat.
- CO2 has risen from about 280 to over 425 parts per million since industrialization.
- A small change in the average drives a large change in extremes.
Check yourself
No grades here. If you can answer these out loud, you own the lesson.
- 1.Explain the greenhouse effect to a younger sibling in three sentences, in any language you like.
- 2.Where does the extra CO2 come from, and since roughly when?
- 3.Why can one degree of average warming produce many more dangerously hot days?