Today, I’d like to start by taking you on a little trip. We will take a rocket and leave the planet earth.
We will pass a thin layer, made of lots of gases called ozone. This is called the ozone layer. The ozone layer is there to protect the planet. First, it allows heat from the sun to come through to the earth to warm it up. It acts a little like a lid to keep the heat in, so it doesn’t get too cold. It also reflects a lot of heat from the sun into space, so that the earth doesn’t get too hot. It also filters out ultraviolet light (UV), from the sun. Some UV is good for us, but too much can be harmful to our skin.
Below the ozone layer, there are also lots of gases which have a similar job as the ozone layer. It acts like a greenhouse - letting in sunlight and trapping the heat to keep the earth at the right temperature. These are known as the greenhouse gases. There are 6 main ones: water vapour, carbon dioxide, methane, ozone, nitrous oxide, and chlorofluorocarbons (CFCs).
Do some of these look familiar? Some of these gases are very similar to the ones we learnt about yesterday that cause air pollution. If they’re similar, why is that a problem?
This is because when there are too many greenhouse gases, it becomes like a thick blanket. It traps too much heat, so that the earth gets too hot. This is called ‘global warming’. The planet gets warmer and also changes our weather patterns - so we have more storms and rains, as well as hotter and drier weather, which makes it difficult for plants and our food to grow and can cause wildfires in the forests. This is called ‘climate change’. But because our weather is getting more unstable and extreme, we now call this the ‘climate crisis’.
The other problem is that some of the chemicals we produce are bad for the ozone layer. There are more than a hundred gases which eat away at the ozone layer, but the main one is called chlorofluorocarbons (CFCs). We used CFCs in fridges and air conditioners to keep us cool, and in aerosol cans.
In 1985 scientists noticed that there was a gigantic hole in the ozone layer over the Antarctic. This now lets in too much heat from the sun, which makes the planet warmer, and also a dangerous level of UV light which burnt our skin and caused skin cancer.
What happened next was incredible. The world came together and promised they would all work together. Scientists listed out more than a hundred gases which are harmful to the ozone layer and everyone agreed that nobody would use them anymore. This was called the Montreal Protocol. It was signed in 1987 by 197 countries - pretty much all the countries in the world.
Scientists around the world kept a close eye on the hole in the ozone layer. And guess what? The hole slowly started to close and got smaller and smaller and smaller. It worked! Now more than 30 years after the Montreal Protocol, the hole in the ozone layer is at its smallest yet. Scientists calculated that the hole in the ozone layer would be completely repaired by 2050.
Now, as many countries around the world have locked down and stopped pumping so many harmful chemicals, this has given the ozone layer an extra helping hand.
So this story shows that, even though the problem may seem impossibly big, we can find a way to solve it, if we all come together and work as a team.
Now, it’s your turn!
Can you think of an example of how you have solved a problem by working as a team? Why don’t you write it down or draw it, so that you can remind yourself of your achievement? Is there a problem that’s troubling you at the moment? Who can you work together with to come up with a plan and you can solve it together?