What is climate change? A really simple guide

Parched earth

Global temperatures are rising due to human activity and climate change now threatens every aspect of human life.

Left unchecked, humans and nature will experience catastrophic warming, with worsening droughts, rising sea levels and mass extinction of species.

The world faces a huge challenge, but there are potential solutions.

What is climate change?

Climate is the average weather in a place over many years. Climate change is a shift in those average conditions.

The rapid climate change we are seeing now is caused by humans using oil, gas and coal for their homes, factories and transportation.

When these fossil fuels burn, they release greenhouse gases, mainly carbon dioxide (CO2). These gases trap the sun’s heat and cause the planet’s temperature to rise.

The world is now about 1.1°C warmer than it was in the 19th century and the amount of CO2 in the atmosphere has increased by 50%.

Bar graph showing how the world has warmed between 1850 and 2020

Bar graph showing how the world has warmed between 1850 and 2020

Temperature rise needs to slow down if we are to avoid the worst consequences of climate change, according to climate scientists. They say global warming must be kept at 1.5°C by 2100.

However, unless further action is taken, the planet could still warm by more than 2C. A 2021 report by the independent group Climate Action Tracker calculated that the world was heading for 2.4C warming by the end of the century.

If nothing is done, scientists think global warming could exceed 4°C in the future, leading to devastating heatwaves, millions of people losing their homes to rising sea levels and the irreversible loss of plant and animal species.

What are the impacts of climate change?

Extreme weather events are already intensifying around the world, threatening lives and livelihoods.

With further warming, some regions could become uninhabitable as farmland turns to desert. East Africa has just seen its fifth season of missed rains, which according to the United Nations World Food Program has put up to 22 million people at risk of severe hunger.

Extreme temperatures can also increase the risk of wildfires, as was seen in Europe last summer. France and Germany recorded about seven times more land burned between January and mid-July 2022 than the average.

Warmer temperatures also mean that previously frozen ground will melt in places like Siberia, releasing greenhouse gases that have been trapped for centuries in the atmosphere, making climate change even worse.

In other regions, extreme rainfall caused historic flooding last year, as seen in China, Pakistan and Nigeria.

People living in developing countries are expected to suffer the most as they have fewer resources to adapt to climate change. But there is frustration on the part of these nations as they have produced fewer greenhouse gas emissions.



The planet’s oceans and habitats are also under threat. Research published in April 2022, funded by the US National Oceanic and Atmospheric Administration, suggests that between 10% and 15% of marine species are already at risk of extinction.

In a warmer world, even land animals will find it more difficult to find the food and water they need to live. For example, polar bears could go extinct as the ice they rely on melts and elephants will struggle to find the 150-300 liters of water a day they need.

Scientists believe that at least 550 species could be lost this century if nothing is done.

barrier Reef

If temperatures continue to rise, nearly all warm-water coral reefs could be destroyed

How will climate change affect the world?

Climate change will have different effects around the world. According to the United Nations climate body, the IPCC, if the global temperature increase cannot be kept below 1.5°C:

  • THE UK AND Europe it will be vulnerable to flooding from extreme rainfall

  • Countries in Middle East they will experience extreme heat waves and widespread drought

  • Island nations in the Pacific Region it could disappear under rising sea levels

  • Many African nations are at risk of suffering from drought and food shortages

  • Drought conditions are likely in the west WEwhile other areas will see heavier thunderstorms

  • Australia it is likely to experience extreme temperatures and increased fire deaths

Internally displaced Somali woman Habiba Bile and her children stand near the carcasses of their livestock that died as a result of severe drought near Dollow, Somalia

Habiba Bile and her children stand near the carcasses of their dead cattle after severe drought near Dollow, Somalia in 2022

What are governments doing?

Countries agree that climate change can only be tackled by working together and, in a landmark agreement in Paris in 2015, they pledged to try to keep global warming to 1.5°C.

In November 2022, Egypt hosted a summit for world leaders, called COP27, where countries came together to make new commitments to tackle climate change.

Many countries have pledged to reach “net zero” by 2050. This means reducing greenhouse gas emissions as much as possible and balancing the remaining emissions by removing an equivalent amount from the atmosphere.

Experts agree that this is still achievable, but it requires governments, businesses and individuals to make substantial changes now.

What can individuals do?

Big changes need to come from governments and businesses, but scientists say a few small changes to our lives can limit our impact on the climate:

Read more about the slogan below about climate change

Read more about the slogan below about climate change

Image above from Getty Images. Visualization of weather strips courtesy of Prof Ed Hawkins and the University of Reading.

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