Zero carbon means that we are not adding any extra carbon into the air. Carbon is a bad thing to have too much of in the air because it makes our planet warmer and can cause bad weather like storms and floods.
To understand this better, let's pretend you have a toy box full of toys. Now let’s say you have a toy that makes a big mess when you play with it, like sand or glitter. When you play with this toy, the sand or glitter gets all over your toys and makes them dirty. This is like carbon going into the air.
Now, if you want to keep your toy box clean, you need to make sure you don't play with that messy toy. This is like people trying to use things like wind and solar power instead of things like coal and oil. When we use these things, they don't create as much carbon, so they help us keep the air clean.
Zero carbon is really important because we want to make sure that our planet is healthy for us to live on. So just like you clean your toy box so your toys can stay safe and healthy, we want to make sure we are keeping our planet safe and healthy too.