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Unlock This CourseThe greenhouse effect is actually essential for life on Earth - without it, our planet would be too cold to support most living things. However, human activities have dramatically increased the amount of greenhouse gases in our atmosphere, creating what we call the "enhanced greenhouse effect". This is causing our planet to warm up faster than ever before, leading to climate change.
Key Definitions:
The natural greenhouse effect keeps Earth about 33°C warmer than it would be without an atmosphere. Water vapour and carbon dioxide naturally trap some heat. The enhanced greenhouse effect occurs when human activities add extra greenhouse gases, trapping even more heat and causing dangerous warming.
Several gases contribute to the enhanced greenhouse effect, but some are much more powerful than others at trapping heat. Understanding these gases and where they come from is crucial for tackling climate change.
While there are many greenhouse gases, four main ones are responsible for most of the enhanced greenhouse effect caused by human activities.
Makes up about 76% of greenhouse gas emissions. Main sources include burning fossil fuels (coal, oil, gas), deforestation and cement production. Stays in atmosphere for hundreds of years.
About 16% of emissions but 25 times more powerful than CO₂. Sources include livestock farming, rice paddies, landfills and natural gas production. Breaks down faster than CO₂.
About 6% of emissions but 300 times more powerful than CO₂. Main sources are agriculture (fertilisers), fossil fuel burning and industrial activities. Very long-lasting in atmosphere.
One molecule of methane traps 25 times more heat than one molecule of carbon dioxide over a 100-year period. This is why reducing methane emissions from farming and waste is so important for fighting climate change quickly.
Since the Industrial Revolution began around 1750, human activities have dramatically increased greenhouse gas concentrations. The main culprits are energy production, transport, industry, agriculture and deforestation.
Burning fossil fuels for electricity, heat and transport is the biggest source of greenhouse gas emissions worldwide, accounting for about 75% of total emissions.
Coal and gas power stations release huge amounts of CO₂. Coal is particularly dirty, producing about twice as much CO₂ per unit of energy as natural gas. Many countries are switching to renewable energy sources like wind and solar.
Cars, lorries, ships and aeroplanes burn petrol, diesel and jet fuel, releasing CO₂. Transport accounts for about 16% of global emissions. Electric vehicles and sustainable fuels are becoming more popular solutions.
Farming and land use changes contribute about 24% of global greenhouse gas emissions through various processes.
Cows, sheep and other ruminants produce methane when digesting food. There are over 1 billion cattle worldwide, making livestock a major methane source.
Nitrogen-based fertilisers release nitrous oxide into the atmosphere. Modern intensive farming uses large amounts of these fertilisers to increase crop yields.
Cutting down forests releases stored carbon and removes trees that absorb CO₂. The Amazon rainforest alone stores about 10% of global carbon.
Global warming caused by the enhanced greenhouse effect is already having serious impacts on our planet. These effects are interconnected and often make each other worse.
Global average temperature has risen by about 1.1°C since pre-industrial times. This might not sound like much, but it's causing dramatic changes worldwide.
The last decade included the 10 warmest years on record. Heat waves are becoming more frequent and intense. Some regions are experiencing temperatures that make it dangerous to work or live outdoors.
Climate change is making storms stronger, droughts longer and flooding more severe. Warmer air holds more moisture, leading to heavier rainfall when storms occur.
Arctic sea ice is shrinking by about 13% per decade. This creates a feedback loop - less white ice means more dark ocean water absorbs heat, causing even more warming. Polar bears and other Arctic wildlife are losing their habitat and indigenous communities are seeing their traditional ways of life threatened.
As the planet warms, sea levels are rising due to thermal expansion of water and melting ice sheets. This threatens coastal communities worldwide.
Sea levels have risen about 20cm since 1900 and are rising faster each decade. Small island nations like Tuvalu and the Maldives face being completely submerged this century.
Oceans absorb about 25% of human CO₂ emissions, making them more acidic. This harms coral reefs and shellfish, disrupting marine food chains.
While the enhanced greenhouse effect presents serious challenges, there are many solutions available. Success requires action from governments, businesses and individuals working together.
Switching from fossil fuels to clean energy sources is the most important step in reducing greenhouse gas emissions.
Solar panels convert sunlight directly into electricity. Costs have fallen dramatically, making solar competitive with fossil fuels in many countries.
Wind turbines generate clean electricity. Both onshore and offshore wind farms are expanding rapidly worldwide.
Using less energy through better insulation, LED lights and efficient appliances reduces emissions and saves money.
Everyone can help reduce the enhanced greenhouse effect through daily choices and lifestyle changes.
Walk, cycle, use public transport, or choose electric vehicles. Flying less or choosing direct flights also helps. Even small changes like combining car trips can make a difference.
Eat less meat, reduce food waste, buy local produce when possible. Choose products with less packaging and repair items instead of replacing them.
Costa Rica generates over 99% of its electricity from renewable sources (mainly hydroelectric, wind and solar). The country has also reversed deforestation and increased forest cover from 30% to over 50% since the 1990s. This shows that rapid progress is possible with the right policies and commitment.
The enhanced greenhouse effect is one of the biggest challenges facing humanity, but it's not too late to act. Scientists agree that limiting warming to 1.5°C above pre-industrial levels is still possible, but it requires rapid and far-reaching changes across all sectors of society. Young people like you will play a crucial role in creating a sustainable future through the choices you make and the leaders you support.