Consequences of Global Warming
The effects of global warming refer to numerous changes due to global temperature rise that are affecting and will affect humanity and the earth. Global warming is the observed and predicted trend towards a higher average global temperature compared to pre-industrial levels, with consequences such as sea level rise, melting glaciers, changing climate zones, vegetation zones and habitats, stronger or more frequent forest fires, altered precipitation, stronger or more frequent extreme weather events such as floods, storms and droughts, the spread of parasites and tropical diseases, and more climate refugees.
While there is broad consensus on the causes of global warming (mainly through human greenhouse gas emissions), this article discusses its consequences. Some consequences are already noticeable, others are only expected in the future.
In addition to the 'linear' projected impacts of global warming described here, there is broad consensus in climate research that there are so-called 'tipping points in the Earth system' that set in motion some sort of domino effect of irreversible change, which is dangerous. for human life on Earth. However, different climate models arrive at different results with regard to the temperature at which this threshold lies. A 2018 meta-analysis concluded that the 2-degree target of the Paris Agreement may not be sufficient to prevent such feedback. Ocean acidification, which is also very environmentally problematic, is not addressed here. This is directly caused by the increasing share of atmospheric carbon dioxide and not by warming.
Expected level of global warming
How much the average temperature will rise during the 21st century depends mainly on the amount of greenhouse gases that are emitted. In its fifth assessment report, the Intergovernmental Panel on Climate Change (IPCC) estimated that global average temperatures would rise by 1.5°C to 4.5°C by 2100, depending on further increases. of the emissions. Rising average temperatures shift the temperature spectrum. While extreme cold spells are less likely to occur, exceptional heat waves are more likely. Due to the possible effects on human health, the economy and the environment, global warming poses major risks, but can also have positive effects locally and regionally. Some environmental changes that both affect humans and ecosystems are already observable. These include rising sea levels, melting glaciers or statistically significant deviations from normal weather patterns. Whether these and other consequences will occur and how severe they will be is judged differently. The effects of climate change are regionally and locally different and have individual consequences. The climate models currently describe the consequences at a global level quite well, but can only estimate them at a regional level with great uncertainty. The trend of warming is foreseeable, and is putting enormous pressure not only on ecosystems, but also on billions of people, for example in terms of water supplies.
How strong the changes will be will depend on how fast climate change takes place. If it happens in a very short time, both the economic adjustment costs and the effects on nature are likely to be felt drastically.
In the 2019 Emissions Gap Report, the United Nations specifies concrete reduction dimensions for climate-damaging greenhouse gases, as the average global temperature will increase by 3.4 to 3.9 °C by the end of the 21st century if emissions remain unchanged. To achieve the target