Read up on: climate change

In the previous video, you watched children engaging with the natural world by walking in a meadow. Children can observe the development of plants, animals, birds and insects through the seasonal cycle, and perhaps also keep their own records of weather conditions, such as temperature, using simple instruments. In order to link this type of activity with a wider understanding of climate change it’s important that children are able to put their observations into a context. Was Spring this year warmer or colder than normal? Is this observation of the flowering date of a particular flower earlier or later than normal, and if so, is that because of unusual weather conditions?

© University of Reading

There is no doubt that the Earth’s climate has changed significantly over the past century, and that this change is outside what would be expected through natural variations in the climate. Human activity, particularly the burning of fossil fuels, is responsible for much of the change. The UN Intergovernmental Panel on Climate Change was set up in the 1980s to study and report upon the state of the Earth’s climate. Their 6th report, published in 2021 has as its headline statement:

It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred.

Understanding the mechanisms that have caused changes in climate can be complex. There are many elements working within the climate system that determine the state of the climate at any given time with a number of feedbacks, both positive and negative, that lead to changes in global temperature and shifts in weather patterns around the world.

At its most basic, the Earth’s climate is controlled by the amount of energy from the Sun entering the earth’s atmosphere, and then by what happens to that energy within the Earth system. Most of the energy coming from the Sun gets through to the Earth’s surface which warms up as a result. The surface then loses energy through infra-red radiation and also through convection of heat and evaporation of water vapour. Most of the infra-red radiation from the Earth’s surface is absorbed by the greenhouse gases in the atmosphere – mostly carbon dioxide, methane and water vapour. These gases occur naturally in the atmosphere and as they absorb infra-red radiation so the atmosphere warms up. The atmosphere then itself radiates in the infra-red, some energy going out to space and some going back down to the Earth’s surface. The balance between incoming and outgoing radiation controls the Earth’s mean temperature and the natural presence of greenhouse gases keeps that temperature at a level which can support life – without them the average temperature of the Earth’s surface would be well below freezing.

Increasing the amounts of the greenhouse gases in the atmosphere shifts the balance and means that the Earth’s surface and atmosphere come into equilibrium at a higher temperature – the root cause of the global heating that has been observed over the past 150 years.

The world’s climate varies naturally and arriving at the conclusion that the planet is warming required measurements of mean temperatures over many years. There is a huge amount of climate change information available on the internet. Some of it is correct, some is unintentionally incorrect and some is deliberately misleading. In the next Step, you’ll discover some reliable and age-appropriate resources that will help you to explain to children why a colder-than-normal spring doesn’t disprove climate change and how they can take measurements themselves and contribute to the international effort to protect the planet.