I spent the summer in my parents spa gazing into the Southland sky. My mind wondered.

I remembered in science class we learned that nothing can be created or destroyed, it just changes its state.

If you heat a block of ice, it turns to water. If you continue to heat the water it turns to steam. 

The water has changed from a solid into a liquid and then into a gas. But the number of water molecules has not changed. 

Antoine Lavoisier discovered this back in 1789. It’s called the law of conservation of mass and it states that mass is neither created nor destroyed, but mass can change its state.

So we can’t create new water, nutrients or carbon for example. And we can’t destroy water, nutrients or carbon either. We can simply watch these things move from one state to another.

If I eat too many nutrients, my body stores them as fat. The only way to get rid of the fat is to eat less nutrients or make my body burn more nutrients. There’s no easy solution. It’s either more exercise or less food. 

It occurred to me that many of the debates we have, are about how we have too much of something or too little of something. 

The law of conservation of mass also means that the mass of an element at the beginning of a reaction will be the same at the end of the reaction.

That basically means you can’t get something for nothing. If you want an output you need to have an equal input.

Vegetables are good for us due to the fact they have lots of nutrients in them. But those nutrients can’t just be created, they have to come from somewhere. They come from the soil. 

We eat the vegetables and our bodies use these nutrients in order to function. Our bodies then expel these nutrients back into the environment in various forms such as methane, sweat or urine.

Farmers need to replace the nutrients which were taken up by the vegetables. They do this by applying fertiliser and usually they have to apply quite a lot of fertiliser because the vegetables have quite a lot of nutrients in them.

We see various food companies promoting how their products use a small amount of water or nutrients etc. That usually means the product itself is low in nutrients.

You can’t get something for nothing.

We have different views on how to replace these nutrients. Should those nutrients be replaced with organic matter like animal manure or should we use conventional fertilisers? 

Both fertilisers are examples of taking nutrients from one state and turning it into another state. With animal manure the animal has eaten the nutrients in the form of grass and then fermented it in their stomach and then extreated out nutrients in the form of dung.

Synthetic nitrogen fertiliser is created using the Haber Bosch process. Which takes nitrogen gas from the air and puts it through a chemical process whereby it becomes a solid. 

We can then put this solid nitrogen onto the soil to grow more vegetables. Food production skyrocketed with this invention and the price of food reduced greatly.

They estimate 40% of the world is fed because of the Haber Bosch process. So we don’t have too little food anymore.

But we do have another problem, that’s too much nutrient in places it shouldn’t be.

We have great debates about nitrogen being in the wrong places and we struggle to find a solution because many people in the chain have to either pay more money or make less money.

Then we have carbon. We dig it out of the ground and turn it into a liquid and put it into our engines and burn it. This turns the carbon into a gas. 

We’re taking carbon out of the ground and putting it into the atmosphere in exchange for forward momentum. Then we plant trees because they absorb carbon gas and store it in the timber. 

We hope this is a good solution, and it is. Until the tree burns down and the carbon returns to the atmosphere again.