What are the causes of climate change? Here are five curiosities about the natural and anthropic causes of climate change. Why are we sure today that it is man’s fault.
After the 5 curiosities about the greenhouse effect , we continue our walk in the climate with the five curiosities about the causes of climate change . As with the coronavirus , many inaccurate news , hoaxes and fake news are circulating about climate change in the web world , but the scientific data has been clear for some time. For example, the first statement that is opposed to the human cause is “but the climate has always changed”.
The climate has always changed in the long history of the earth, but for different causes which do not imply that human action is dominant today. Here because.
1. The Greenland buffalo
A widespread fake news is the myth of green Greenland in the era of the Viking colonization around the year 1000 AD The thesis of the skeptics of the anthropic cause of climate change maintains that since the Viking Erik the Red called that island Greenland, green land, it means that it was much hotter then today and therefore we should not worry about global warming.
In reality the name “green land” was born because only one part, the colonized one, was green. Greenland, then as today, has been covered for 84% by ice for at least 400,000 years. This does not exclude that some areas of Greenland that were greener than they are today but this was not a general phenomenon throughout the territory.
luca lombroso@LucaLombroso
L’energia del sole, i cicli astronomici e il surriscaldamento della Terra https://www.youtube.com/watch?v=HFcSmF3QLzE&feature=youtu.be&fbclid=IwAR21m5UoYWBTmhXV33PxhM63ErGLJ9FAtUqDmuCM5syF3OVc2VJQPJwn9FY … @ilmeteonet
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02:42 – 16 apr 2020
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2. Astronomical causes: the sun shows no real signs of change
The main natural cause of climate change are the astronomical cycles of the sun . Among these, we cite the variation of eccentricity of the Earth’s orbit, which has a cycle of 120,000 years, the obliquity of the orbit, with a cycle of 41,000 years and the precession of the equinoxes, 22,000 years. As we understand, we are well beyond the times of human scale, these phenomena in short are not able to explain the changes taking place today .
Equally the changes in solar activity, including the eleven-year sunspot cycle, are not such as to justify the changes underway.
luca lombroso@LucaLombroso
Quattro passi nel clima: I cambiamenti climaticihttps://www.youtube.com/watch?v=0einMMx-Tls … @ilmeteonet
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07:22 – 16 apr 2020
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3. Geological causes: who smokes more than one volcano?
Large geological changes also act as internal forcing in climate systems. Among these we mention the drift of the continents, it is clear that the arrangement of the emerged lands changes the disposition of cyclones and anticyclones and alters the general circulation of the atmosphere. However , this too is a slow phenomenon, which acts on hundreds of millions of years and cannot explain the strong warming of the last century .
Read also. Volcanoes erupting in the world in April 2020: the videos
Another important geological factor are volcanic eruptions. Certainly volcanoes have a strong influence of the climate , on the one hand for the degassing of CO2 and on the other for the release of ash and SO2, which vice versa have cooling effects. However, this is a short-term effect, while man smokes much more than volcanoes
4. Anthropic causes: the only justification
Only anthropogenic causes can justify the extent and speed of the changes underway .
Climate models can reconstruct the climate of the past well, but without introducing the anthropogenic forcings due to greenhouse gases, deforestation and land use change there is no justification for the changes taking place today.
Moreover, thirty years after the first IPCC reports, today we have evidence of how much the expected changes are taking place on time.
Read also. Climate crisis and stop to flights, food for thought
5. The IPCC key phrases from 1990 to today
It was 1990 and the IPCC , the Intergovernmental Commission on Climate Change, established two years earlier by UNEP and WMO, issued its first evaluation report . The key phrase spoke of doubts and evidence of global warming . Five years later, in the second report, there was talk of the first evidence of the human cause. In 2001, the IPCC acknowledged that ” human activities are likely (67% confident) to be the dominant cause of climate change .
Read also. 5 curiosities about the greenhouse effect
In 2007, in the fourth report, any doubts about warming were resolved, declaring that ” global warming is unequivocal and is most likely due to human causes “. In AR5, in 2014, the human cause is defined as extremely probable .
The latest IPCC document is the SR global Warming 1.5 ° C, which states that ” human activities caused a 1 ° C warming compared to the pre-industrial era “.
In short, it is time to act, as we are rightly listening to epidemiologists and virologists on the Coronavirus emergency, politics must listen to climate science and act accordingly.
