What is climate Change and How are humans causing climate change?

Human activities are causing world temperatures to rise, posing serious threats to people and nature.

Things are likely to worsen in the coming decades, but scientists argue urgent action can still limit the worst effects of climate change.

What is climate change?

Climate change is the long-term shift in the Earth's average temperatures and weather conditions.

The world has been warming up quickly over the past 100 years or so. As a result, weather patterns are changing.

Between 2015 and 2024, global temperatures were on average about 1.28C above those of the late 1800s, known as pre-industrial levels, according to the European Copernicus climate service.

Since the 1980s, each decade has been warmer than the previous one, the UK Met Office says.

The year 2024 was the world's hottest on record, with climate change mainly responsible for the high temperatures.

It was also the first calendar year to surpass 1.5C of warming compared to pre-industrial levels, according to Copernicus.

How are humans causing climate change?

The climate has changed naturally throughout the Earth's history.

But natural causes cannot explain the particularly rapid warming seen over the last century, according to the UN's climate body, the Intergovernmental Panel on Climate Change (IPCC).

This has been without doubt caused by human activities, in particular the widespread use of fossil fuels - coal, oil and gas - in homes, factories and transport systems.

When fossil fuels burn, they release greenhouse gases - mostly carbon dioxide (CO2). This CO2 acts like a blanket, trapping extra energy in the atmosphere near the Earth's surface. This causes the planet to heat up.

Since the start of the Industrial Revolution - when humans started burning large amounts of fossil fuels - the amount of CO2 in the atmosphere has risen by more than 50%, far above levels seen in the Earth's recent history.

The CO2 released from burning fossil fuels has a distinctive chemical fingerprint. This matches the type of CO2 increasingly found in the atmosphere.

**How Climate Change Is Already Affecting the World**

Climate change is already causing big problems in many parts of the world. Some of the major effects include:

* More frequent and stronger extreme weather, like heatwaves, floods, and heavy rainfall.

* Fast melting of glaciers and large ice sheets, which leads to rising sea levels.

* Arctic sea ice is getting smaller every year.

* Oceans are getting warmer, which can lead to stronger storms and also harms fish and other sea life.

These changes are not just about nature — they are also hurting people and economies all over the world.

For example, in January 2025, wildfires in Los Angeles caused massive damage. Experts believe the total cost could go over \$100 billion, making it one of the most costly weather disasters in U.S. history. While there were many reasons for the fires, scientists from the World Weather Attribution (WWA) group said that climate change made the hot and dry conditions more likely, which helped the fires spread.

Another example happened in 2022 in East Africa. That region went through its worst drought in 40 years. More than 20 million people faced the risk of extreme hunger. The WWA found that climate change made such a drought at least 100 times more likely.

Not everyone is affected in the same way. How badly a person or community suffers depends on how prepared they are and how vulnerable they are to extreme events. Poorer communities often suffer the most because they have fewer resources to protect themselves.

Climate change is not a future problem — it is happening now.