What causes climate change?

Earth is a very special planet – its orbits close enough to the sun to receive a lot of energy, but far enough away not to be scorched.

It is in what you might call the "goldilocks zone", where the conditions are just right for life as we know it.

To help keep these conditions constant, our planet is wrapped in a layer of greenhouse gases.

This layer acts like a blanket, keeping the earth warm and shielding it from the cold of universe. This is commonly referred to as the greenhouse effect.

Carbon dioxide (CO2), which, while not  the most potent greenhouse gas,  is nevertheless the main driver of the greenhouse effect.

When fossil fuels - coal, oil and natural gas - are burnt they  release CO2 into the atmosphere. 

Because of this the layer of greenhouse gas is getting thicker, which is in turn making the Earth warmer.

Thus the ongoing  unlimited burning of fossil fuels is the cause of climate change.

In order to satisfy our endless hunger for energy we are buring unlimited quantities of fossil fuels.

But, this does not have to be the case,  thanks to human ingenuity there are now smarter ways to make energy.

About Carbon Dioxide

CO2 can be harmless enough when dissolved in a drink – it adds sparkle to mineral water, soft drinks and champagne. However, when excess amounts are released into the atmosphere it can cause untold damage. How CO2 causes global warming.

Where does CO2 come from?

In terms of fuels, the main problem is coal. The other key reason is waste – inefficient use of energy.

And in terms of industries, the main culprit is electricity production – the power industry.
	© WWF Germany / Andrew Kerr
The average coal-fired power plant wastes twice as much energy heating up the planet as it converts to useful electricity.
© WWF Germany / Andrew Kerr

Culprit coal

The biggest climate polluter is the global power sector which generates around 40% of all global electricity from coal. We need electricity - but when you take into account the true cost of coal there are much better ways to get it!

According to the International Energy Agency the power sector is responsible for 37% of all man-made Carbon Dioxide (CO2) emissions. It creates about 23 billion tonnes of CO2 emissions per year – in excess of 700 tonnes a second.

In turn, this CO2 continues to heat up our planet which poses an unprecedented threat to us and the environment.

Generating electricity through the burning of fossil fuels, in particular carbon-heavy coal, has a greater impact on the atmosphere than any other single human activity.

Coal is the world's most widely available fossil fuel

Weaning humanity off coal will not be easy. There is an estimated 2 billion people with no access to domestic electricity, and recoverable reserves of coal exist in about 70 countries, according to the World Coal Institute, an industry lobby group (the largest reserves are in the United States, Russia and China). Coal is considered a cheap form of energy.

But coal is not cheap - if you have to pay for it all

The true cost of coal is not found on any balance sheet, but in the lives and health of people and ecosystems. If the global power sector could be made fully accountable for the true costs of pollution and climate change, it would probably turn away from fossil fuel overnight.

Too many governments still subsidize coal production which distorts the energy market. OECD countries support their coal industry with a whopping US$30 billion annually.

Much cleaner renewable energies are hampered in their ability to compete with a dirty fuel that is so heavily subsidized. Politicians have the power to remove fossil-fuel subsidies or, better still, transfer them to renewable energy.

When the true cost of coal is taken into account, renewable energy begins to look by far the best option for a healthy and sustainable future.

Why coal causes so much environmental damage

Coal is the sedimentary organic rock formed from vegetation that lived millions of years ago.

Coal is the most carbon-rich of all fossil fuels. Burning coal generates 70% more carbon dioxide (CO2) than natural gas for every unit of energy produced. Coal is the sedimentary organic rock formed from vegetation that lived millions of years ago.

The most mature coal variety, anthracite - hard, black and lustrous - is nearly pure carbon, and has historically been regarded as useful to humans because of its high energy content. But dirty brown coal, or lignite, produces most CO2 per unit of energy.

Above all, more than a third of all global electricity is generated from coal - it is the power sector's single biggest source of energy.


	© WWF
Browse the map of Europe's worst coal fired power stations.

Costs of coal

    • Asia-Pacific carbon emissions are predicted to increase by 85% in the next two decades. Already half of global mercury emissions come from Asian fossil-fuel power plants.
    • Mercury emissions from coal-fired power plants cause acid rain, which costs some US$90 billion every year in the Asia Pacific region alone.
    • Research shows that 1in 6 women of childbearing age in the USA may have blood mercury concentrations high enough to damage a developing foetus, according to the Earth Policy Institute (EPI).
    • In the United States, 23,600 deaths a year are attributed to air pollution from power plants. The burning of coal is also responsible for some 554,000 asthma attacks, 16,200 cases of chronic bronchitis, and 38,200 non-fatal heart attacks annually.
    • Each second 700 tonnes of CO2 are spewed into the atmosphere from coal fired power plants
    • To run a single 100-watt light bulb 24 hours a day for a year a coal fired power plant will produce around 840 kilograms (1852 pounds) of CO2.

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