Climate Change

What is Climate Change?

Climate change is a large-scale, long-term shift in the planet's weather patterns and average temperatures.


Global temperatures have risen significantly over the 20th and 21st centuries, driven primarily by an increase in atmospheric carbon dioxide caused by the burning of fossil fuels. Since the Industrial Revolution, atmospheric carbon dioxide levels have increased by over 40% to levels that are unprecedented in at least 800,000 years. This has caused a global warming effect which has changed global climate patterns.

What causes Climate Change?

The main cause of global warming is an increase in the level of greenhouse gases in the atmosphere. The main greenhouse gases are water vapour, carbon dioxide, methane, nitrous oxide and Chlorofluorocarbons (CFCs).


Of the greenhouse gases emitted by humans, carbon dioxide is by far the most important, simply because we produce far more carbon dioxide that any of the other gases. Carbon dioxide is produced naturally when animals breath, or when a volcano erupts or there is a forest fire.

However, the burning of fossil fuels over the last 150 years has dramatically increased the amount of carbon dioxide in the atmosphere from 280 parts per million (ppm) at the time of the Industrial Revolution, to 405ppm in 2017. Carbon dioxide naturally absorbs heat radiated from the earth's surface, and re-emits this heat back into the atmosphere, causing a warming effect. So much carbon dioxide has been emitted into the atmosphere over the last 150 years that global average temperatures are estimated to have increased by between 1 and 1.2 degrees Centigrade, a very significant increase which is still continuing.

What are the impacts of Climate Change?

Climate Change is already having consequences for our planet and the species that depend on it (i.e. us). Research indicates that the Earth's temperature will keep going up for the next 100+ years. This would cause more snow and ice to melt, resulting in higher sea levels. Some places would get hotter, though other places might have colder winters with more snow. Some places might get more rain whilst other places will get less rain. Increasing average temperatures will change long term weather patterns across the globe, though most
dramatically at the poles where effects are accentuated.

Climate Change is likely to cause:

  •  Mass extinctions of species which are unable to adapt to the changing climate

  • The submergence of coastal communities and small island states due to a rising sea level

  • Death and disease among  fish, algae, coral and other organisms in the sea due to the absorption of excessive atmospheric carbon dioxide, acidifying the oceans

  • An increase in extreme weather phenomenon such as droughts, heavy rainfall/snowfall (and associated flooding) and large storms. This will increase deaths, victims, refugees and material damage.

  • Mass human migration away from affected areas. Climate refugees are a reality; it is estimated their number could reach one billion by 2050. 

"There's one issue that will define the contours of this century more dramatically than any other, and that is the urgent threat of a changing climate."

Barack Obama, President of the United States

"On an increasingly crowded planet, humanity faces many threats - but none is greater than climate change. It magnifies every hazard and tension of our existence."

Prince Charles

"The clear and present danger of climate change means we cannot burn our way to prosperity. We already rely too heavily on fossil fuels. We need to find a new, sustainable path to the future we want. We need a clean industrial revolution."

Ban Ki-moon, Secretary General of the United Nations

“Preservation of the environment, promotion of sustainable development and particular attention to climate change are matters of grave concern for the entire human family”

Pope Benedict

You can make a difference

We have just a few years left to cut our global carbon emissions by 50%. The Earth needs climate heroes! With everyone's help we can do this.

Act now by following the action plan below to cut your carbon footprint.

Download the Action Plan.

Ready for more?

Take a look at the many other ways you can conserve energy and reduce emissions.

Please sign our Climate Emergency petition.



Here at St.Albans and District Friends of the Earth we’re keen to do what we can to improve our environment here and in the rest of the world. We’re a small, friendly group who meet once a month. 

© 2019 St. Albans Friends of the Earth