I'm sure there is some complicated, scientific explanation of what biodiesel is, but that might confuse you. Honestly, it would confuse me. So, let's try to keep this as simple as possible.

Biodiesel is an alternative fuel source derived from natural oils. It is biodegrable, renewable, and non-toxic.

How is it good for the environment?

Say the biodiesel you use is made from corn. While that corn grows, it absorbs carbon dioxide from the environment. So, when you use this diesel, any carbon dioxide emissions are made up for by the absorption from growing the plant. It kind of balances out.

This cycle of absorption and emissions of carbon dioxide sounds pretty great, right? I agree. It is a fabulous alternative to other, more toxic, fuel sources (like oil).

Biodiesel is renewable. Renewable is defined as a resource that can be sustained or renewed, indefinitely.

Biodiesel is biodegradable. Biodegradable is defined as something that can rapidly decompose naturally (definitely not your Styrofoam cup sitting in a landfill for eternity).

Biodiesel is non-toxic. Non-toxic is defined as a substance that will not have harmful effects on living organisms (particularly human beings).

Biodiesel can create a ripple effect around the planet that cannot be measured. This ripple effect could manage to harm the environment. While biodiesel controls carbon dioxide emissions, its global footprint could be fairly damaging.

Crops, like corn and soybeans, are being used to make biodiesel. This means that these crops are in high demand, as a food source and a fuel source. To meet the growing demand of these crops, they are being grown in areas of the world where they weren't before. To keep up with the demand of the global food supply, and the growing demand for biodiesel fuel, more land is being converted for agricultural uses.

Prices for these food crops have already gone up, but will continue to rise as the the demand grows. As well, these crops require large amounts of water--something that could lead to water shortages in the areas where they are grown. The pesticides and fertilizers used to grow these crops can contaminate the local water supplies.

Another concern is for that land that is being converted for agricultural use (or the land that could potentially be converted). Forests could demolished and poorer people could be forced out of their land.

Is biodiesel good or bad?

I don't think anyone can really argue that biodiesel is worse for the environment than using fossil fuels is. The important thing to remember is that we need balance. There is not simply one answer for saving the world. Our planet--our environment--is complex, so we need a combination of solutions to make this a healthier, more sustainable place to live.

It comes down to each one of use making the decision to live green.