Causes of climate change
Burning fossil fuels, cutting down forests and raising livestock are increasingly affecting the Earth's climate and temperature.
This adds huge amounts of greenhouse gases to those released naturally into the atmosphere, increasing the greenhouse effect and global warming.
Global Warming
The years 2011 to 2020 are the warmest decade on record, with the global average temperature reaching 1.1°C above pre-industrial levels in 2019. Human-caused global warming is currently increasing by 0.2 °C per decade.
A temperature increase of 2°C compared to pre-industrial temperatures would lead to serious negative impacts on the natural environment and human health and well-being, including a much higher risk of dangerous and potentially catastrophic environmental changes.
For this reason, the international community has recognized the need to keep the rise in temperatures below 2°C and to work towards limiting it to 1.5°C.
Greenhouse gases
The main driver of climate change is the greenhouse effect. Certain gases in the Earth's atmosphere act somewhat like glass in a greenhouse, trapping the sun's heat and stopping it from returning to space, causing global warming.
Many of these greenhouse gases exist naturally, but human activities lead to an increase in the concentration of some of them in the atmosphere, in particular:
- carbon dioxide (CO 2 )
- methane
- nitrous oxide
- fluorine-containing gases
CO2 produced by human activities is the most important contributor to global warming. By 2020, its concentration in the atmosphere has risen to 48% above pre-industrial levels (before 1750).
Other greenhouse gases are released by human activity in smaller amounts. Methane is a stronger greenhouse gas than CO2, but has a shorter lifetime in the atmosphere. Nitrous oxide, like CO2, is a long-lived greenhouse gas that builds up in the atmosphere over decades and centuries. Pollutants other than greenhouse gases, including aerosols such as soot, have different warming and cooling effects and are linked to other problems, such as poor air quality.
Natural causes, such as changes in solar radiation or volcanic activity, are thought to have contributed less than plus or minus 0.1°C to the overall warming between 1890 and 2010.
Reasons for the rise in emissions
- Combustion of coal, oil and gas releases carbon dioxide and nitrous oxide.
- Deforestation (deforestation). Trees help regulate the climate by absorbing CO2 from the atmosphere. When they are cut, the beneficial effect is lost and the carbon stored in them is released into the atmosphere, increasing the greenhouse effect.
- Increase in livestock farming. Cows and sheep produce large amounts of methane in the digestion process.
- Nitrogen-containing fertilizers produce nitrous oxide emissions.
- Fluorinated gases are released from equipment and products that use these gases. Fluorine-containing gases have a very strong warming effect — up to 23,000 times stronger than that of CO2.
Combating climate change
Since every ton of CO2 released into the atmosphere contributes to global warming, reducing all emissions helps slow this process. To stop global warming entirely, we need to achieve zero net CO2 emissions. In addition, reducing emissions of other greenhouse gases, such as methane, can also have a strong impact on slowing global warming, especially in the short term.
