// one of Australia's best-known Science Communicators and Futurists

Everybody is talking about Climate Change, Global Warming, and the Greenhouse Effect. But what is the Greenhouse Effect? Well, I'm glad you asked!

Imagine that you are at a market garden, standing outside a tomato glasshouse or greenhouse on an autumn day with a thermometer in your hand. The temperature might be 17 degrees Celsius. Go inside the greenhouse and you could well find that the temperature is nearly 30 degrees Celsius. Light energy from the Sun passes through the clear glass or plastic walls and roof of the greenhouse and warms the air, soil and plants inside. Infrared heat energy radiated from the soil and plants cannot escape through the transparent walls and roof, so the temperature inside rises. And generally, plants grow better when they are warmer. This is the Greenhouse Effect and it's great for growing plants.

On a large scale, the Earth's atmosphere acts like a giant greenhouse - trapping heat near the Earth's surface. In a way, this is a good thing. Without the Greenhouse Effect, the Earth would be freezing cold all year round.

However, in recent times, we've been using up fossil fuels (coal, oil, and gas) at an alarming rate - putting extra carbon dioxide into the atmosphere and increasing the Greenhouse Effect. The climate is changing! The globe is warming! If we can decrease our dependency on fossil fuels, and increase our capacity to use renewable energy sources (such as solar, wind, waves, and geothermal energy) then we may be able to reduce the Greenhouse Effect and slow down Global Warning. That will be good news for Planet Earth.