What is climate change?
Climate change refers to a large-scale, long-term shift in the planet's weather patterns and average temperatures. Climate change is the long-term shift in average weather patterns across the world. Since the mid-1800s, humans have contributed to the release of carbon dioxide and other greenhouse gases into the air. This causes global temperatures to rise, resulting in long-term changes to the climate.
How are humans changing the climate?
In the 11,000 years before the Industrial Revolution, the average temperature across the world was stable at around 14°C. The Industrial Revolution began in the mid-1800s when we began to burn fossil fuels such as coal, oil, and gas for fuel.
Burning fossil fuels (coal, oil, gas) produces energy, but also releases greenhouse gases such as carbon dioxide and methane, into the air. Over time, large quantities of these gases have built up in the atmosphere.
For example, the level of carbon dioxide in the atmosphere rose by 40% during the 20th and 21st century and is now over 400ppm (parts per million). This level of carbon dioxide is higher than at any time in the past 800,000 years!
Once in the atmosphere, greenhouse gases such as carbon dioxide form a 'blanket' around the planet. This blanket traps the heat from the sun and causes the earth to heat up. This effect was noticed as far back as the 1980s. In 1988, the International Panel on Climate Change (IPCC) was set up to provide governments with information to tackle climate change. www.ipcc.ch
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Radio weather forecast
Listen to the weather forecast. Compare audio and television forecasts to identify similarities and differences in the language used.
What is a rainbow?
The rainbow is one of the most amazing colourful meteorological events. In simple terms it is formed by the properties and behaviour of light, and how it interacts with water droplets. It is an arc-shaped spectrum of light which is created by refraction and reflection.
Refraction is the bending of light as it passes from one transparent substance into another.
Reflection is the return of light or sound waves from a surface.
Humans have been fascinated with rainbows and their formations for centuries. The Greek philosopher Aristotle first started thinking about rainbows and their colours back in 350 BC. Fast forward to 1665 when Sir Isaac Newton the famous Mathematician and Scientist undertook an experiment whilst studying at Cambridge University by bending white light through a prism. He was interested in learning about light and colours.
A prism is a three-dimensional shape with identical ends, called bases, and flat sides called faces.
He concluded that clear white light was made up of a spectrum of colours by splitting light with a prism!
Red, orange, yellow, green, blue, indigo and violet. These are the colours of the spectrum and the colours of the rainbow!
Rainbows are formed when rays of light from the sun hit water droplets which reflects the light back towards the person. The water droplets are usually rain drops but could also be spray from a waterfall, a fountain or even fog. To see a rainbow, you must have the sun shining behind you.
The arc of the rainbow that is visible depends how high the Sun is in the sky. If the Sun is very high you may see a rainbow that just only appears above the horizon. If you saw a rainbow from a high mountain or an aeroplane it would be a whole circle!
Thunder and lightning
What causes lightning?
Lightning is an electric charge. Small pieces of ice strike each other in a cloud and create an electric charge, and wow! That's lightning!
Lightning is red hot – around 30,000°C (54,000°F), which is six tmes hotter than the sun!
What causes thunder?
The high temperature makes the air expand suddenly. The air then explodes and creates soundwaves. We hear these as thunder. As light moves 900,000 times faster than sound we see the lightning before hearing the thunder.
How far away is the storm?
You can see lightning about 100 miles away. Thunder is heard about 15 miles away in a quiet rural area and about 5 miles away in a noisy city.
You can tell how far away a thunder and lightning storm is by counting the seconds between the lightning and the thunder and dividing that by 5. If you count 10 seconds the storm is 2 miles away!
What should we do in a thunder and lightning storm?
• Getting close to trees is dangerous.
• If you are in a group of people it is a good idea to keep about 15 feet apart.
• Swimming or snorkelling is not safe because water is an excellent conductor of electricity.
• A small puddle of water is dangerous in a thunder and lightning storm.
• Clothes lines and fencing posts are dangerous because they are made of metal.
• Lightning can strike a phone wire, so using the house phone is dangerous.
Did you know that the thunder and lightning occur at the same time? We see the lighting before hearing the thunder. Do you know why?
Playing with nature
15 March 2021
It is true enough that the money comes from us, the privileged people of the West. But are we just easing our consciences? Is climate change our fault? If you don't think it is changing, ask Turaqulov, a farmer in
Tajikistan.
"I think the weather has warmed in the last four years and it's affecting our crops. We lose 30 per cent of them to different diseases."
Unlucky? Try unfair. Why? Because it’s the rich countries that produce the greenhouse gases that cause climate change and the poorest countries that suffer most.
When flooding occurs in Britain, help is readily available to us. It's very difficult for people in poor countries to make ends meet, so they don't have any savings to use in an emergency. Poor diet, lack of sewerage and lack of effective health care also spread diseases.
The situation is already dire but disaster is on the horizon. It’s a fact that levels of carbon dioxide and methane are higher today than they have been in the last 420 years.
Perhaps seeing what happens to the weather in Wales will persuade us to change our way of life.
In November 2021 the UN climate conference will be held in Scotland with 197 countries represented to discuss global warming issues.
