Over the last 200 years we have seen enormous change in the human population from around 1 billion in 1820 to more than 7 billion today, and the way people live is taking its toll on the planet.
Extreme weather, water shortages and polluted ecosystems are some of the problems caused by modern lifestyles.
The good news is that we can change this situation if each of us is willing to act and do our bit. Solutions will come if we all choose to learn and work together. If we don’t react then humanity will certainly face disaster.
Scientists say our planet is close to a tipping point, which could result in runaway changes that will be very difficult to control.
The Earth could absorb most of our impacts when there were fewer people but not anymore. Our ever-increasing population and consumer lifestyles place an unsustainable demand on natural resources.
According to the World Wildlife Fund (WWF), each year we are using resources 1.5 times faster than the Earth can supply. As an example, imagine you had R12 000 to spend on food for a whole year. It would make sense to spend just R1 000 a month. But if you decided to spend R1 500 a month (1.5 times your monthly budget), what would happen? You would run out of money after month eight and not survive after that.
One problem you may have heard of is climate change. Some people are sceptical about it, but 97% of the world’s expert climate scientist’s agree that it is happening and is caused by human activity.
A lot of the science focuses on modelling the effects of greenhouse gases in the atmosphere. Increasing levels of these gases cause surface and atmospheric temperatures to rise, changing weather patterns and causing violent storms, flooding and long periods of drought.
For humans a hotter Earth is generally not a good idea. Carbon dioxide (CO2) is just one of a number of greenhouse gases emitted by human activity such as producing electricity from coal-fired power stations and using transport driven by burning fossil fuels. For every litre of petrol burnt in a car engine, about 2.25kgs of CO2 ends up in the atmosphere.
Transport accounts for around 11% of our greenhouse gas emissions. Look out for the coming articles to find out how we can change this.
1. What was the population of the world in 1820?
2. True or False: The world’s population has doubled in the last 200 years.
3. What is a tipping point?
4. Name three impacts of increased human population on the Earth.
5. What does WWF stand for?
6. True or False: We are using resources 1.5 times faster than Earth can supply.
7. What happens when greenhouse gases increase in the atmosphere?
8. What is the chemical formula for carbon dioxide?
9. Name the two main energy activities in SA that rely on burning fossil fuels.
10. How much carbon dioxide equivalents is emitted for every litre of petrol used by a car?
See answers on page 10