We have been putting so much CO2 and other greenhouse gases into the air that scientists can measure it. Before 1800, the average amount of CO2 was 275 parts per million. Today, that number is 387 parts per million, an increase of 40 per cent. That is like putting an extra blanket on the Earth. Every year, it is increasing. Unless we can change how we build things, how we get around, how we heat our homes and how we eat, the amount of CO2 will reach double pre-industrial levels within 60 years.

All that extra greenhouse gas is already having an effect. I said earlier that the average temperature around the world is just less than 15 degrees. Before we started burning coal and oil, it was about 14 degrees, an increase of 0.7 degrees. That may not sound like a big change, but even a little warming can have a big impact on environments around the world. The past few years, more and more ice has been melting from the Arctic Ocean. At this rate, there will be no more ice at the North Pole in 20 or 30 years. Forests are burning faster, drought is becoming more common and some hurricanes are stronger. This is just the beginning of climate change.

Scientists are uncertain what could happen if we do not stop burning so much oil and coal. Somethink that it may increase temperatures by as much as 6 degrees by 2100. This would be the biggest, fastest change in temperature in many thousands of years. We do not know what will happen. Sea levels could rise, and many people that live near the water would lose their homes and their land. Water could dry up in many regions, making it impossible to grow food. Many of the species that make our planet so beautiful would go extinct.