World temperatures are rising because of human activity, and climate change is now threatening every aspect of human life.
If the situation is not controlled, humans and nature will experience catastrophic warming, with worsening droughts, further sea level rise and mass extinction of species.
We face a big challenge, but there are potential solutions.
What is climate change?
Climate is the set of average conditions of temperature and environment in a place, over many years. Climate change is a change in these average conditions.
The rapid climate change we are now seeing is caused by the human use of oil, gas and coal for homes, factories and transportation.
When these fossil fuels burn, they release greenhouse gases — primarily carbon dioxide (CO2). These gases trap the Sun’s heat and cause the planet’s temperature to rise.
The planet is now about 1.2°C warmer than it was in the 19th century — and the amount of CO2 in the atmosphere has increased by 50%.
The pace of temperature rise needs to slow down if we are to avoid the worst consequences of climate change, scientists say. They claim that global warming needs to be kept at 1.5°C by the year 2100.
However, unless other actions are taken, the planet could still warm by more than 2°C by the end of this century.
If nothing is done, scientists believe that global warming could exceed 4ºC, leading to devastating heat waves, millions losing their homes due to rising sea levels and irreversible loss of plant and animal species.
What is the impact of climate change?
Extreme weather events are already more intense, threatening lives and livelihoods.
With additional warming, some regions may become uninhabitable as farmland turns to desert. In other regions, the opposite is happening, with extreme rains causing historic flooding — as seen recently in China, Germany, Belgium and the Netherlands.
People in the poorest countries will suffer the most as they don’t have the money to adapt to climate change. Many cities in developing countries already have to put up with very hot climates and this is only going to get worse.
Our oceans and their habitats are also threatened. The Great Barrier Reef in Australia, for example, has lost half of its corals since 1995 due to warmer seas caused by climate change.
Wildfires are becoming more frequent as climate change increases the incidence of hot, dry weather.
And as the frozen ground melts in places like Siberia, greenhouse gases trapped for centuries will be released into the atmosphere, exacerbating climate change.
In a warmer world, animals will have a harder time finding the food and water they need to live. For example, polar bears can die as the ice they depend on melts, and elephants will struggle to find the 150-300 liters of water they need each day.
Scientists believe that at least 550 species could disappear this century if measures are not taken.
How will different parts of the world be affected?
Climate change has different effects in different areas of the world. Some places will heat up more than others, some will receive more rain and others will face more droughts.
If the temperature rise cannot be kept within 1.5°C:
• The UK and Europe will be vulnerable to flooding caused by extreme rains
• Middle Eastern countries will experience extreme heat waves and farmland could turn to desert
• Island nations in the Pacific region could disappear with rising seas
• Many African nations may experience droughts and food shortages
• Drought conditions are likely in the western US, while other areas will see more intense storms
• Australia is likely to experience extreme heat and drought
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 committed to trying to keep global warming to 1.5°C.
The UK will host a summit for world leaders, called COP26, in November, where countries will define their carbon reduction plans for 2030.
Many countries have committed to achieving carbon neutrality by 2050. This means reducing greenhouse gas emissions as much as possible and balancing the remaining emissions by absorbing an equivalent amount from the atmosphere, through carbon capture technologies, for example.
Most experts believe this is possible, but it will require governments, companies and individuals to make major changes.
What can individuals do?
Big changes need to come from governments and companies, but scientists say a few small changes in everyday life can limit our impact on the climate:
• Take fewer flights
• Do not use cars or opt for an electric car
• Buy energy efficient products like washing machines when they need replacement
• Switch from a gas heating system to an electric heat pump
• Use material that insulates your home from the cold and heat, thus avoiding heating and air conditioning
