One thing us human beings are pretty good at is solving problems. There's nothing like the challenge of a tricky situation to get our creative juices flowing. Admittedly, the problems are usually caused by us in the first place, but, you can't deny that when we find ourselves buried up to our necks, we can usually dig ourselves out.

Just look at the problem of dog poo. It's everywhere. There are yucky, stinky, stomach-turning, mouth-gagging lumps of shit left in every park in every city in the world.

In the dog-friendly city of San Francisco, dog poo counts for nearly 4% of residential waste.
That's an awful lot of mess to clear up.

But, those clever problem-solving San Francisco city officals have come up with the idea of turning dog poo into biofuel. In a pilot programme starting later this year, dog poo will be collected from one of the city's most popular dog parks and run through a methane digester in which bacteria break down the poo to create methane gas. This biofuel can then be piped to a cooker, a heater or anything else that uses natural gas. It can even be used to generate electricity.

It's not going to solve the world's energy crisis.
But with millions of dogs in the world you never know. The point is that even though we have lots
of problems, we should never give up hope.

Because without hope we'll never find the answers.

Illustration by Joby Barnard