Climate change definition
What is climate change? In very simplified terms, climate change refers to the overall cooling or warming of Earth's climate over a long period of time.
According to the recommendations of the World Meteorological Organization (WMO), climate data are always tracked over a minimum of 30 years. Observation over a long period of time means that there can be upward or downward swings. This contrasts with weather, which is observed over short periods of time ranging from hours to days.
Climate change shows the long-term change in factors such as temperature, precipitation, and ocean currents. This affects the entire ecosystem: changes in the circulation of the atmosphere, rising ocean temperatures, changes in precipitation distribution, melting ice caps, rising sea levels, shifting vegetation zones, and the extinction of species are examples of such far-reaching changes.
What is causing climate change?
Over time, there have been various changes to our planet’s climate. However, the temperature increase that we have experienced in the last 200 years is faster than anything that has occurred previously. This rapid change cannot be explained by natural processes; the main cause of global warming is human activity. The burning of fossil fuels such as coal and oil, as well as changes in land use and the resulting deforestation, release vast quantities of greenhouse gases. The gases accumulate in the earth's atmosphere and, through the greenhouse effect, cause the climate to warm over time.
Climate change and global warming
Global warming is one aspect of the broader changes to the climate. Since the Industrial Revolution began in the late 18th century, the average global temperature has risen by more than 1 °C. Two-thirds of this warming has occurred since the mid-1970s, and each subsequent decade has been warmer than the one before. Alarmingly, the effect is even more extreme in the Arctic, causing sea ice to decrease significantly.
What are the effects of climate change?
The climate is a complex system, and no one can predict exactly what will happen if greenhouse gases continue to be released in large quantities. However, the prognosis for passing the tipping point is clear. It will cause further changes to the climate with irreversible consequences.
Due to our way of life and our consumption patterns, large amounts of greenhouse gases like carbon dioxide, methane, and nitrous oxide are being released into Earth's atmosphere. Examples of these emission sources include industrial processes, agriculture and forestry, transport, and energy production. As a result, the average global temperature continues to rise.
Of course, not only the land is warming, but also the oceans, and the increased evaporation has further consequences. Sea levels are rising due to the melting of the polar ice caps and glaciers, and eventually whole swathes of land will be flooded and become uninhabitable for humans and animals. Areas of permafrost cover a quarter of the Northern Hemisphere, but as the perpetual ice thaws, the stored greenhouse gases are released into the atmosphere.
As the climate continues to change, extreme weather will increase all over the world and long periods of drought or flooding will become more frequent. The agricultural sector will become increasingly threatened, affecting livelihoods and food supply. The consequences of climate change will eventually affect everyone, but the impacts are already being felt, especially in the Global South.
Climate change adaptation
Climate change is a threat to all life on Earth. That is why it is so important that the targets of the Paris Agreement are met and that the global temperature increase is limited to 2 °C above pre-industrial levels, ideally to just 1.5 °C. But in addition to mitigating global warming to meet this target, we must also adapt to the irreversible effects.
Measures that support adaptation while also reducing emissions are particularly valuable, such as well-insulated buildings that reduce heat stress in summer, minimising energy consumption and thus avoiding emissions. In this way, climate action must also be considered in economic terms: the more climate change progresses, the more expensive the measures we must take to adapt to its consequences become.
In addition, to contribute to the global climate action effort, these measures must be coupled with investment in climate projects that reduce or avoid emissions around the world.
How can we reduce our impact on climate change?
Companies and individuals can start by calculating their carbon footprint to assess where their emissions derive from. From here, measures can be taken to reduce and avoid emissions. Most important is that nations, companies, and individuals all do their part, while recognising that this is an unprecedented and changing situation. Mitigation measures that are successful now may be ineffective in the future. The climate must continue to be closely monitored, the science must continue to advance, and our responses must continue to adapt.
Learn more about taking action to mitigate climate change with the ClimatePartner Academy.