Climate change refers to long-term changes in global temperatures and weather patterns.
While Earth's climate has always varied naturally, the speed and scale of current climate change are largely driven by human activity. Human activities are responsible for approximately 1.1°C of warming since 1850-1900. Understanding the causes of climate change is essential to tackling its impacts and reducing future harm - particularly for the 2.4 billion children whose futures depend on the choices we make today.
Updated in January 2026
The Greenhouse Effect
To understand what causes climate change, we first need to understand the greenhouse effect. The Earth's atmosphere contains gases - including carbon dioxide, methane and nitrous oxide - that trap some of the sun's heat. This natural process keeps our planet warm enough to support life. Without it, Earth would be too cold for humans to survive.
The problem arises when we add too many greenhouse gases to the atmosphere. These extra gases trap more heat, causing global temperatures to rise. It's like wrapping the planet in an increasingly thick blanket. The more greenhouse gases we release, the warmer the planet becomes.
A portrait of Atika, 12, at her family’s farm in drought-affected East Sumba, Indonesia.
(L - R) Audrey, eight, Rosie,9, Diekololaoluwa, eight, Andres, seven, Lenny, nine, and Poppy, eight, taking part in a beach clean-up with their school, Margate Photo credit: Kate Stanworth / Save the children
The Main Human Causes of Climate Change
Scientists agree that human activities are unequivocally causing global warming.
Here are the primary ways human actions contribute to climate change:
Burning Fossil Fuels
Burning coal, oil and gas for energy is the single largest cause of climate change. When we burn these fossil fuels to generate electricity, power vehicles, heat buildings or manufacture goods, they release carbon dioxide and other greenhouse gases into the atmosphere.
In the UK, total emissions in 2024 were 371 million tonnes of carbon dioxide equivalent - though this represents a 54% reduction since 1990, we're still releasing huge amounts of greenhouse gases. The energy sector remains a major contributor, though the shift from coal to renewable energy sources has helped reduce emissions substantially over recent decades.
Transport is another significant source. UK domestic transport sector emissions account for a substantial portion of total greenhouse gas emissions. While transport emissions have reduced by 15% between 1990 and 2024, they remain a major challenge as vehicle use continues.
Deforestation
Forests absorb carbon dioxide from the atmosphere, acting as vital carbon stores. When forests are cut down - whether for agriculture, timber or urban development - this stored carbon is released back into the atmosphere. Worse still, we lose the trees that would have continued absorbing carbon dioxide in the future.
The scale of deforestation is staggering. Approximately 10.9 million hectares of forest were lost each year between 2015 and 2025. In 2024 alone, the tropics lost a record-shattering 6.7 million hectares of primary rainforest - an area nearly the size of Panama, disappearing at a rate of 18 football fields per minute.
Deforestation is particularly severe in countries like Brazil, where the Amazon rainforest - often called the "lungs of the Earth" - continues to shrink. Between 2000 and 2020, the Amazon lost an area roughly equivalent to the size of Spain.
Agriculture and Livestock Farming
Agriculture contributes to climate change in several ways. Rice paddies release methane as rice grows in waterlogged fields. The production and use of synthetic fertilisers releases nitrous oxide, a greenhouse gas nearly 300 times more potent than carbon dioxide.
Livestock farming, particularly cattle, is a major source of methane emissions. Cows produce methane during digestion, and their manure releases both methane and nitrous oxide. The global livestock sector is responsible for approximately 14.5% of all human-caused greenhouse gas emissions.
Additionally, vast areas of forest are cleared to create grazing land for cattle or to grow crops for animal feed, compounding the problem through deforestation.
Industry and Manufacturing
Manufacturing processes for products like steel, cement, plastics and chemicals are highly energy-intensive and release substantial greenhouse gases. The production of cement alone accounts for approximately 8% of global carbon dioxide emissions.
In the UK, the manufacturing sector saw emissions of 65 million tonnes of CO₂ equivalent in 2024, representing a decrease from previous years but still a significant contribution to overall emissions.
Waste and Landfills
When organic waste like food scraps and garden waste breaks down in landfills without oxygen, it produces methane. As our global population grows and consumption increases, the amount of waste we generate - and the methane it produces - continues to rise.
The way we dispose of other materials matters too. Incinerating waste releases carbon dioxide, while improper disposal of electronic waste can release harmful chemicals into the environment.
Natural Causes of Climate Change
While human activities are the primary drivers of current climate change, natural processes do influence Earth's climate. Understanding these helps us appreciate why scientists are certain that recent warming is human-caused.
Volcanic Eruptions
Volcanic eruptions release gases and particles into the atmosphere. While volcanoes do emit carbon dioxide, the amount is relatively small compared to human emissions - approximately 100 times less than what humans produce annually.
Interestingly, major volcanic eruptions can actually cool the planet temporarily. They release tiny particles called aerosols that reflect sunlight away from Earth, leading to short-term cooling. However, this effect lasts only a few years before temperatures return to their previous trend.
Changes in the Sun's Energy
The sun's energy output varies slightly over time, following an approximate 11-year cycle. These variations do affect Earth's climate. However, careful measurements show that solar activity cannot account for the warming observed since 1950. In fact, solar activity has slightly declined over recent decades while global temperatures have continued to rise.
Natural Climate Cycles
Earth experiences natural climate cycles, such as El Niño and La Niña events in the Pacific Ocean, which can temporarily warm or cool global temperatures. Over much longer timescales, variations in Earth's orbit (called Milankovitch cycles) have triggered ice ages and warmer periods throughout Earth's history.
However, these natural cycles occur over thousands to hundreds of thousands of years. The rapid warming we're experiencing now - approximately 10 times faster than the average rate of warming after an ice age - cannot be explained by natural cycles alone.
Why Human Causes Matter Most
The evidence is overwhelming that human activities are the dominant cause of the climate change we're experiencing today. Scientists estimate that human emissions and activities have caused around 100% of the warming observed since 1950.
Here's why they're so certain:
Natural factors like solar variations and volcanic eruptions would have caused slight cooling over the past 50 years if they were acting alone. Instead, we've observed significant warming. The pattern of warming we see - with the lower atmosphere heating while the upper atmosphere cools - is exactly what we'd expect from greenhouse gas increases, not from natural causes like increased solar activity.
Carbon dioxide from human activities is increasing about 250 times faster than it did from natural sources after the last Ice Age. The speed of this change is unprecedented in Earth's recent history.
The consequences are already visible. The 10 warmest years ever recorded have all happened in the last decade. This isn't a coincidence - it's the direct result of human activities pumping greenhouse gases into the atmosphere.
Every morning, 12-year-old Ratana sets off from her home on Cambodia’s Tonle Sap Lake by boat. She’s heading for a floating school supported by Save the Children – but she’s got a vital job to do before she gets there. As she rows she picks up friends along the way – and together they work to clear the rubbish that litters the lake. It is children like Ratana and her friends that are this fishing community’s best hope of saving their lake and livelihood. It is her generation that is leading the fightback against climate change across the world.
How Save the Children Helps Communities Adapt to Climate Impacts
At Save the Children, we understand that while addressing the causes of climate change requires global action, children in the world's most vulnerable communities are already living with its devastating effects. That's why we're working alongside communities to help them adapt and build resilience.
We know from our research with over 54,500 children in 41 countries that climate change and inequality are deeply interconnected. The children who have done the least to cause climate change are suffering the most from its impacts. According to our Generation Hope report, 774 million children worldwide are both living in poverty and at high risk of climate-related disasters.
Our programmes focus on practical solutions that protect children now while building long-term resilience. We're introducing solar-powered water systems in drought-affected areas, training families in climate-resilient agriculture so they can continue to feed their children despite changing weather patterns, and constructing climate-resilient schools and healthcare facilities that can withstand extreme weather events.
In 2024, we supported the construction of over 1,150 climate-resilient classrooms in nearly 230 schools in Mozambique - a country repeatedly hit by devastating cyclones. These classrooms protect children during extreme weather and ensure learning can continue even when disaster strikes.
But adaptation alone isn't enough. We're also advocating for urgent action to tackle the root causes of climate change. We're calling on governments and businesses to rapidly phase out fossil fuels, invest in renewable energy, protect and restore forests, and ensure that the transition to a green economy is fair - particularly for the communities and children most affected by climate impacts.
The causes of climate change are clear. The solutions exist. What's needed now is the political will to act with the urgency this crisis demands - before more childhoods are stolen by a problem they didn't create.
