You might think we know everything there is to know about climate change. We know that greenhouse gases, such as carbon dioxide and methane, are trapping heat. And we know that average temperatures are climbing worldwide. But there’s still lots for us to learn, and new discoveries are being made all the time. For example, did you know that arctic seabirds fight climate change? Well, it’s not the birds themselves. Actually, it’s their poo.
Huge colonies of sea birds often nest on rocky outcrops. And lots of nests means lots of bird poo! Technically known as guano, bird poo contains lots of ammonia, which is a chemical often found in the fertilisers that farmers use on plant crops. In fact, people used to mine bird poo to make fertiliser! If the poo is left out in the weather – and it always is, because birds aren’t very good at cleaning – some of that ammonia makes it into the air.
Up in the air, the bird-poo ammonia meets up with molecules of sulfuric acid. This corrosive chemical comes from creatures living in the ocean. When ammonia and sulfuric acid then meet up with water vapour, the three combine into tiny particles.
Over time, more water vapour joins the particles, and they grow into tiny droplets. If there are enough droplets, a cloud forms. The bright white cloud bounces sunlight straight back out into space, keeping Earth shady and cool.
A team of scientists from around the world has measured the ammonia coming from bird nesting sites, as well as the levels of cloud-forming particles. They added this information into computer climate simulations, and found that yes, seabird poo is actually helping to cool our planet.
So if you’re worried that scientists already know everything, don’t be. As this story shows, there’s still plenty that we don’t understand about our planet. And maybe one day you’ll be a scientist, discovering new things too.
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