A changing planet2017.05.08
RECENTLY, people have begun to realise that even space-age technology can cause problems for the planet, changing it in unexpected ways. Since the end of the 20th century, scientists have been studying these changes to find out what they might mean for all of us – and for the planet – in the future.
THERE are more people alive today than ever before. That means people need more food, water, space to grow food and build homes, factories to make things and power to run all our machines, homes and cars.
In recent years, the number of people on the planet has been growing faster than ever before.
ALL the land and water that people take leaves less for the wildlife. Many factories and cities spew out pollution – harmful substances that kill plants and animals. And now that people can travel anywhere they want, not even wild places are safe for wildlife. Many types of plants and animals are becoming extinct.
EVEN more worrying, scientists have discovered that electricity and petroleum oil are not any cleaner than coal. Electricity is clean once it has been made, but to make it, people often burn coal first. And burning both coal and petroleum releases masses of carbon dioxide, or CO2, into the atmosphere.
CO2 is what is known as a greenhouse gas. It builds up in the Earth’s atmosphere, forming a layer that traps the Sun’s heat, and this warms up the planet. It is not just burning fossil fuels that produces CO2 – natural things like volcanoes and lightning make it too. Some people are not sure whether it is CO2 from fossil fuels or from other things that is responsible for warming the planet.
EXPERTS agree that over the last 250 years, the amount of CO2 in the atmosphere has increased by one third. And during the last 100 years, Earth’s temperature has warmed up by around 0.5C.
In many parts of the world there is not enough clean water to go around. This will probably get worse, because of growing numbers of people and less predictable rainfall. Scientists are working on solutions, such as drinking straws with filters inside. These let people drink any water safely.
LOTS of experts around the world are working hard to find solutions to the problems of climate change. But it is not easy.
THERE are some power sources that do not produce CO2, including wind power and solar power from the Sun. Unfortunately, if the wind stops blowing, or the Sun is not shining, the power stops. But people still need to run their computers, lights and cars. So, until someone finds a clean power source that works all the time, we will still need to get some energy from sources that release CO2.
Fixing the problem
SCIENTISTS are starting to find ways of capturing CO2 released by fossil fuels, so it does not escape into the atmosphere and warm the planet. They are also working on all the things that use power – appliances, engines and so on – so that they work more efficiently and use less power.
Reduce, re-use, recycle
THERE are lots of small changes people can make to help save the planet, too. Less CO2 will be released from cars, planes, factories and power stations if we all reduce the amount of power we use and the amount of stuff we buy, and if we try to re-use what we can and recycle more.
What about the future?
WE now know that people have a huge impact on the story of Planet Earth. What happens in that story in the future depends partly on us. But it also depends on many other things we cannot control. Unexpected events have changed our world again and again, from Ice Ages to asteroid strikes to even the start of life itself. Only one thing is certain: as long as there is a Planet Earth, it will always go on changing.
(Excerpt from The Story of Planet Earth . There are many other stories in it about our home. Usborne titles are available in Bookazine, Commercial Press and Fun to Read Outlet.)