Climate change basics





45 minutes


Learning Path

This course will give you all the basic information you need to understand climate change and the issues it causes, as well as an introduction to the ways you can help reduce global warming.

Start by watching this short video by National Geographic to get an idea of what climate change is all about. Then read on to learn in more detail exactly what causes it and what you can do.

When energy comes from the sun to the Earth, most of it is reflected from the earths surface back into space. This insures the Earth does not get too hot. However, some of the energy that reflects off the surface of the Earth hits the ozone layer (in the atmosphere), and is reflected back down to Earth. This process is natural and has always occurred on Earth. It is the reason the temperature on Earth is around 15 degrees and not -50 degrees. This is also the reason why the moon’s temperature at night is -173 degrees celsius and 127 degrees celsius during the day  because it has no atmosphere to reflect the energy coming from the sun or keep the energy on the planet.

However, when we release more greenhouse gases, such as carbon dioxide, the atmosphere gets thicker. This means that more energy is reflected back to Earth, and so the temperature on Earth rises. This is called the enhanced greenhouse effect because it is similar to the process which makes a garden greenhouse so hot.

Remember that there is a difference between the natural greenhouse effect and the enhanced greenhouse effect. The problem of climate change is caused by the temperature rise caused by the enhanced greenhouse effect.

Read our article on the greenhouse effect to find out more detail about how more greenhouse gases in the atmosphere lead to rising temperatures.


Our earth is constantly changing, with or without climate change. It goes through cycles of major warming and major cooling periods. Temperatures can go to as high as 40ºC during the interglacial period and as low as -89ºC during the major glacial period. These periods are caused by Earth’s orbits around the sun called Milankovitch cycles which can range between 10 000 – 100 000 years. So if our earth has been warmer before, why is it such a problem that it is warm now?

Right now we are supposed to be in a cooling period. However, anthroprogenic climate change is interrupting this cooling, and we are raising the temperatures all too quickly at the moment. Some of our highest temperatures recorded are very recent. On 16 August 2020 a temperature of 54.4°C was recorded in Furnace Creek, California. Humans are speeding up the warming process too soon and too quickly, which can seriously affect the eco-systems that are in place.

While this warming period may not be an emergency for some species adapted to hotter temperatures, humans will not be able to survive by themselves. This warming will lead to more resources being used to try and mitigate or adapt to global warming, resulting in even more environmental degradation. Ultimately, the increased warming exacerbates humans’ damage to the earth, and will eventually lead to the environment’s destruction.

As man made global warming warms the earth’s average surface temperature, there are two direct impacts on the earth:

  1. The sea levels rise
  2. There is more severe weather

These two changes to our environment have catastrophic impacts. Each of these needs to be understood to know what is at risk with our planet and why we need to do something about it.

Rising Sea Levels

As our planet’s average temperature increases, more glaciers and ice sheets melt, causing more water to be added to the sea and rising sea levels. As the temperature of the sea rises, thermal expansion occurs and sea levels rise more. Currently, the sea levels rise by about 3.6mm a year. This doesn’t seem at first glance to be all that bad. However, this rise is continuous and in a few decades, many coastal cities face a huge risk of flooding, including places like Miami, New York, Rio de Janeiro and Shanghai just to name a few of the many cities facing this threat. Millions of people will have to be displaced as their homes become flooded and billions of dollars will have to be spent on seawalls and other protective measures just to keep their cities safe. The rising sea levels also give rise to increased storm surges which leads onto the other significant problem.

Increases Severe Weather

The increase in average global temperature enhances the already problematic natural disasters, including storms, hurricanes and wildfires.

Hurricanes and Storms

As sea levels rise and the temperature of the sea increases, storms can gain more energy from the sea and air, making them larger and last for longer.  This has devastating effects on any place that experiences hurricanes as they are about to get far worse. Look at 2020 for example, a record number of hurricanes have hit the east coast of America with higher wind speeds and longer durations. This is a clear example of how global warming enhances the natural disaster.


With a rising average air temperature, the chances of a wildfire starting increases, leading to more fires and more land burned. In 2018, 8.8 million acres of land were burned compared to roughly 3.3 million acres in 1990. To put this into perspective, the area lost every year because of the increase in global warming is the same area as 3.1 million football pitches, which almost seems unreal. If all of that land was instead used for planting wheat to feed people, there would be another 1.5 x 1010 loaves of bread per year. This would probably be enough to solve world hunger. These figures really  put the problem of climate change into perspective. So many problems can be solved or helped by reducing man made global warming.

The best way to deal with climate change is understanding exactly what you can do to help reduce it and acting on that information.

Follow these next three steps to start doing something meaningful.

1. Inform yourself on how much of an impact you have right now

It is best to understand what you need to reduce before you start to reduce your carbon footprint. You can find out about your own carbon footprint and how to reduce it by taking the carbon footprint calculator. This will give you a rough idea of how much you contribute to global warming compared to the average UK citizen. You can compare the carbon footprint of any two actions using our comparison tool. A great book to read is called ‘How bad are bananas?’ by Mike Berners-Lee. This will give you an insight into the impact of many actions you do daily.

2. Change your actions so that you and your family contribute less to climate change

Once you have found out how much you contribute, hopefully you will start to realise what small actions can make a big difference. Turn off the light bulb; fly less; use public transport or walk; turn down your house heating; only buy local food from the supermarket. Even though these have been said before, they are still just as valid. We understand that it is hard to sacrifice things straight away like meat eating or travelling by plane. Yet every small action makes a difference so start with something small and keep changing your lifestyle slowly to make it better for the environment.

3. Raise awareness about climate change so that more people act to reduce their impact

By sharing what you have learned with friends and family you make sure more people understand climate change, how serious it is, and what they can do. To help the most, you can direct them to our website where they can learn exactly how to reduce their carbon footprint.

Complete this quiz to test your knowledge of this course:

Whats primary cause of climate change?
What has the biggest carbon footprint?
What fraction of greenhouse gas emissions are carbon dioxide?
What would the earths temperature be if there was no atmosphere?
How much does the sea level rise every year?


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