What is climate change? The definition, causes and effects

0
33


IS the Earth getting hotter or colder? Why should we care?

Here’s what we know and don’t know about our planet’s changing climate.

Climate change is being caused by a number of different reasons, some of which are man made
AP:Associated Press

What is climate change?

The planet’s climate has constantly been changing over time.

The Earth’s average temperature is about 15C, but some evidence suggests it has fluctuated between much higher and much lower in the past.

However, the current period of warming is occurring more rapidly than many past events.

Climate scientists are concerned that the natural fluctuation is being overtaken by a huge human-induced warming that has serious consequences for the stability of the planet’s climate.

One of the causes of rising temperatures are greenhouse gases
AP:Associated Press

What is causing climate change?

A natural function of the Earth’s atmosphere is to keep in some of the heat that is lost from the Earth. This is known as the greenhouse effect.

The atmosphere allows the heat from the Sun (short-wave radiation) to pass through to heat the Earth’s surface.

The Earth’s surface then gives off heat (long-wave radiation).

This heat is trapped by greenhouse gases (eg methane, carbon dioxide and nitrous oxide), which radiate the heat back towards Earth.

This process heats up the Earth.

Some human activities increase the greenhouse gases in the atmosphere:

  • Burning fossil fuels, eg coal, gas and oil – these release carbon dioxide into the atmosphere.
  • Deforestation – trees absorb carbon dioxide during photosynthesis. If they are cut down, there will be higher amounts of carbon dioxide in the atmosphere.
  • Dumping waste in landfill – when the waste decomposes it produces methane.
  • Agriculture – agricultural practices lead to the release of nitrogen oxides into the atmosphere.

What are the natural factors affecting climate change?

There are also natural factors which contribute to increased global warming:

  • Orbital changes – the Earth has natural warming and cooling periods caused by Milankovitch cycles or variations in the tilt and/or orbit of the Earth around the Sun (Wobble, roll and stretch theory).
  • Volcanic activity – during a volcanic eruption carbon dioxide is released into the atmosphere.
  • Solar output – there can be fluctuations in the amount of radiation from the sun. If there is high amount emitted there will be an increase in Earth’s temperatures.


What are the effects of climate change?

Global warming can have negative impacts on the world.

Negative impacts of global warming around the world include: sea levels rising that will affect 80 million people; tropical storms will increase in magnitude (strength); species in affected areas (eg Arctic) may become extinct; diseases such as malaria increase, an additional 280 million people may be affected.

But there might also be some positive impacts of a warmer climate around the world including: energy consumption may decrease due to a warmer climate; longer growing season for agriculture; frozen regions such as Canada may be able to grow crops.


We pay for your stories! Do you have a story for The Sun Online politics team? Email us at tips@the-sun.co.uk or call 0207 782 4368. We pay for videos too. Click here to upload yours.


 

LEAVE A REPLY

Please enter your comment!
Please enter your name here