Climate Change

Climate change is a long-term shift in the planet's weather patterns and average temperatures. Earth's climate has changed naturally many times over its 4.5 billion year history, but the change happening today is different: it is much faster than natural cycles and is being driven mainly by human activity. Since the Industrial Revolution began around 1750, the average global temperature has risen by about 1.2 degrees Celsius, and it is still climbing. That may not sound like much, but it is already changing weather, melting ice and putting wildlife in danger all around the world.

• Temperature rise since 1750Around 1.2 CAnd still climbing
• Main causeGreenhouse gases from humansCO2, methane and others
• Atmospheric CO2 in 1750280 ppmParts per million
• Atmospheric CO2 in 2025Over 420 ppmHighest in 800,000 years
• Sea level rise since 1900Around 20 cmAnd accelerating
• Global goalNet-zero by 2050Set by the UK and many others

What is climate change?

The climate of a place is its average weather over many years. Weather is what is happening right now (rain, sunshine, snow), while climate is the pattern that repeats over decades. Climate change means that those long-term patterns are shifting: average temperatures, rainfall, wind patterns, the timing of seasons and the frequency of extreme weather are all changing.

Scientists know climate change is happening from many lines of evidence:

• Thermometers around the world show steady warming since 1880.
• Ice cores drilled from Greenland and Antarctica show CO2 levels higher than anything in the last 800,000 years.
• Sea levels are rising as ice melts and warm water expands.
• Glaciers and Arctic sea ice are shrinking year after year.
• Coral reefs are bleaching as oceans warm.
• Springs are arriving earlier and migrations are shifting.

What is causing it?

The main cause of modern climate change is greenhouse gases released by humans into the atmosphere. Greenhouse gases let sunlight through but trap heat from leaving, like a glass roof on a greenhouse. The most important ones are:

• Carbon dioxide (CO2): from burning fossil fuels (coal, oil, gas), making cement and cutting down forests. About 75% of the warming effect.
• Methane (CH4): from cattle, rice paddies, landfill rubbish and natural gas leaks. Strong but breaks down faster than CO2.
• Nitrous oxide (N2O): mainly from farming fertilisers.
• Fluorinated gases: small amounts from refrigeration, electronics and other industries, but extremely strong per molecule.

Some climate change is also caused by natural processes (volcanic eruptions, small changes in the Sun, Earth's orbital wobbles), but these are tiny compared to the human contribution since 1750.

Fact Atmospheric CO2 in 2025 is over 420 parts per million (ppm). That is the highest in at least 800,000 years (we know from bubbles trapped in old ice). The pre-Industrial Revolution level was just 280 ppm. The change is unprecedented in geological terms. Earth has never warmed this fast before.

What climate change is doing to the planet

• Melting ice: glaciers in the Alps, Andes and Himalayas are shrinking. Arctic sea ice has dropped by about 13% per decade since 1979. Greenland and Antarctica are losing billions of tonnes of ice each year.
• Rising sea levels: oceans have risen about 20 cm since 1900 and are now rising about 3.4 mm per year. Coastal cities like London, Miami, Jakarta and Venice are at increasing risk of flooding.
• More extreme weather: heatwaves, droughts, wildfires, hurricanes and torrential rain events are all becoming more common and intense.
• Ocean acidification: a third of the extra CO2 dissolves into the sea, making it more acidic. Bad for corals, shellfish and plankton.
• Wildlife in trouble: many animals and plants cannot move or adapt fast enough. Polar bears, coral reefs, pollinators and migratory birds are all under stress.
• Threats to people: crop failures, water shortages, displacement of coastal communities, increased disease range, plus economic damage running into trillions of pounds.

What is being done about it?

Countries around the world are working together to slow climate change. The most important international agreement is the Paris Agreement (2015), signed by nearly every country. It aims to limit global warming to well below 2 degrees Celsius, and ideally below 1.5 degrees, compared with pre-industrial levels.

To get there, countries are doing things like:

• Switching electricity generation from coal and gas to wind, solar, nuclear and hydroelectric.
• Phasing out new petrol and diesel cars in favour of electric vehicles.
• Replacing gas boilers with electric heat pumps.
• Insulating buildings to use less energy.
• Planting trees to absorb CO2 from the air.
• Developing new technology to capture carbon directly from chimneys.

The UK was the first major economy to legally commit to net-zero emissions by 2050: meaning the country should not be adding any extra greenhouse gases to the atmosphere by then.

Did you know? In October 2024 the UK shut down its last coal-fired power station, ending 142 years of coal-powered electricity. The UK is the first major industrial economy to fully phase out coal. Most of its electricity now comes from gas, nuclear, wind and solar.

What can kids do to help?

• Walk, cycle or use public transport when you can, rather than asking for a car lift.
• Turn off lights, TVs and devices when you leave a room.
• Wear an extra jumper before turning up the heating.
• Use a reusable water bottle instead of buying plastic ones.
• Eat less red meat (beef and lamb have the highest carbon impact).
• Recycle paper, glass, metal and plastic properly.
• Avoid food waste, plan meals and eat leftovers.
• Choose second-hand clothes or pass yours on when you have grown out of them.
• Plant trees, herbs or wildflowers at home or with your school.
• Talk about climate change with friends and family, the more people care, the more politicians act.

Try this Track your family's electricity use for one week using your smart meter or bill. Then try a "low-carbon week": LED bulbs only, no tumble dryer, shorter showers, washing on 30 degrees, no heating boost, and see how much the reading drops. Calculate the savings: every kWh saved is roughly 200 grams of CO2 kept out of the air. Multiply by the whole country and you can see why small daily choices add up.

Deeper dive: the difference between weather and climate

One of the most common confusions about climate change is the difference between weather and climate. They sound similar but mean very different things.

Weather is what is happening in the atmosphere RIGHT NOW or over a few days: rain, snow, wind, temperature today, this week's forecast. Weather changes hour by hour and is hard to predict more than about 10 days in advance.

Climate is the AVERAGE weather of a place over 30 years or more. It tells you what to expect at a particular time of year, on average: how cold a typical winter is, how much rain a typical summer brings, how often hurricanes hit a region.

The difference matters because climate change is about long-term shifts. A single very cold winter does NOT disprove climate change, because winter is weather, not climate. Climate scientists look at decades of data, not single events.

A useful way to picture it: imagine a person walking a dog on a long lead. The dog is the weather, wandering left and right, sometimes ahead, sometimes behind. The person is the climate, walking steadily in one direction. The dog's wandering can look random, but the person sets the trend. Climate scientists watch the person, not the dog.

This is why headlines like "Coldest February in 30 years, so much for global warming" miss the point. Local cold spells still happen, but the long-term trend, decade after decade, is unmistakably warmer. The "person" really is walking in one direction, and that direction is up.

For more, see global warming and Earth Day.