 The main driver of climate change is the burning of fossil fuels. Fossil fuels come in three main types, coal, oil and gas. They're all carbon-based energy sources and when we use them to generate energy we burn them. And the byproduct of burning them is carbon dioxide. Now carbon dioxide is an innocuous gas as far as us humans are concerned directly. It's not poisonous, you can't smell it, you can't see it. But it has a very interesting property. It absorbs heat being radiated out from the earth's surface. And that's the so-called greenhouse effect. So why is it called greenhouse? Well you know how a greenhouse works. If you put plants in a greenhouse that glass traps heat, keeps it warmer and the plants grow better. Well CO2 acts as a giant greenhouse around planet earth. So the sun's radiation warms the earth's surface and to keep an energy balance so we don't burn up the earth has to emit energy back out to space. But it doesn't do this by light, it does it by heat. This heat is just the right wavelength for carbon dioxide to absorb a fair bit of it. That actually keeps the planet habitable so carbon dioxide is a natural part of the atmosphere. But the problem is we are burning so much coal, oil and gas so fast that the amount of carbon dioxide in the atmosphere is rising very rapidly. This is trapping more outgoing heat. This raises the earth's surface temperature and this is climate change because climate is what we feel as humans in the lower atmosphere. And so the bottom line here is quite clear. Burning fossil fuels raises the earth's temperature. Having a hotter atmosphere changes the climate system. Changes rainfall, changes extreme events, makes life more difficult for us and the rest of life on the surface of the earth.