What is climate change?
The average weather in an area over several years is referred to as the climate. Climate change is defined as a change in the state of the climate that can be detected (e.g. using statistical tests) over decades or longer., Simply put climate change refers to long-term shifts in temperatures and weather patterns.
The cause?
Changes in solar radiation inputs and outputs from the sun to the earth, as well as from the earth to space, change the climate. The greenhouse effect is the science behind climate change; as greenhouse gases rises, less heat is emitted back into space and as a result ,the earth warms.
There have been numerous episodes of climate change throughout Earth's history. However, the global temperature has risen at a much faster rate since the Industrial Revolution in the 1800s. Human activity has quickly become the leading cause of climate change by burning fossil fuels, deforestation, and changing how we use the land. Carbon dioxide and other greenhouse gases are emitted into the atmosphere because of these activities.
There is more carbon dioxide in the atmosphere today than there has been in at least two million years and carbon dioxide levels increased by 40% between the twentieth and twenty-first centuries.
Why should we care?
Climate change will affect all of us – and future generations – in a number of ways:
- Climate change will (and in some places it already has) change our way of life, causing water shortages and making food production more difficult.
- Because of rising sea levels, some areas may become dangerously hot and others uninhabitable.
- Polar ice and glaciers are rapidly melting, putting low-lying coastal areas at risk of flooding from rising seas.
- Extreme weather events, such as heat waves, torrential rains, and storms, will become more common and intense, posing a threat to people's lives and livelihoods.
- Conditions such as sea-level rise and saltwater intrusion have already forced entire communities to relocate, and prolonged droughts are putting people at risk of famine.
- The number of 'climate refugees’ is expected to rise in the future. People in poorer countries, who are least able to adapt, will take the greater burden of the consequences. However, the effects are felt worldwide, including in developed countries. The unprecedented flood in Germany, as well as the increasing wildfires in the United States and Australia, are recent examples of these effects.
Climate change is – and will continue to – have a detrimental effect on the animal kingdom:
- Some species will be able to move to new locations as their habitats change. However, because climate change is occurring at such a rapid rate, many species are likely to become extinct. Polar bears are in danger of vanishing as the ice on which they rely melts.
- As the river waters in which they breed warm up, Atlantic salmon could be wiped out.
- As the oceans absorb CO2 and become more acidic, tropical coral reefs may become extinct.
How is the world responding?
The reduction of greenhouse gas emissions, which must reach zero as soon as possible, is at the heart of tackling climate change. Because some level of climate change is already happening, the response now is based on two approaches:
- Mitigation: Reducing greenhouse gas emissions and stabilising the levels of heat-trapping greenhouse gases in the atmosphere. For example, this means moving from fossil fuel to renewable energy, or restoring nature to absorb more carbon.
- Adaptation: Adapting to climate change is already underway. For example, this means improving community resilience, efficient farming, and making changes to the way we live our lives.
Globally, in 2015 through The Paris Agreement, world leaders from 197 countries pledged to prioritise people and reduce their countries' greenhouse gas emissions. The Paris Agreement aims to keep global warming well below 2°C, ideally below 1.5°C. Governments from 197 countries will gather in Glasgow in November 2021 for the UN Climate Change Conference, known as COP26.
Further information
- The ABC of Climate Change
- IPCC Climate Report ‘Code Red for Humanity’
- IPCC Sixth Assessment Report: The Physical Science Basis
- Adaptation and Mitigation in fighting climate change