With the arrival of 2021, the question of where the virus came from is expected to have an answer but it has thousands of theories but no definite answer. Although, according to a study in the journal 'Science of the Total Environment' the answer may be closer than it seems, and the main reason for the emergence of COVID could be climate change.
The study argues that global greenhouse gas emissions over the last century have made China an ideal location for the transmission of these diseases by bats. This process is explained by the fact that the new environmental conditions provide favorable habitats for the reproduction of these animals.
It also points out that the increase in temperatures, higher atmospheric carbon dioxide levels, irregular precipitation patterns and a greater incidence of solar radiation create an ideal breeding ground for the appearance of tropical forest environments and deciduous forests. An ecosystem that is perfect for the birth and reproduction of these mammals.
The study is based on the fact that the number of cases that proliferate in a region is linked to the number of species that exist in that region. In this way, and in greater depth, it dares to determine that the greater the number of individuals, the greater the risk of COVID being transmitted in that area.
The article determines that 40 species of bats have moved into the province of Yunnan over the last century. "Understanding how the global distribution of bat species has changed as a result of climate change may be an important step in reconstructing the origin of the COVID outbreak," says Robert Beyer, a researcher in the Department of Zoology at the University of Cambridge.
Part of this process is explained by a map of global vegetation distribution. From it, the researchers located the bat species around the world and thus, were able to calculate the number of individuals of each species that existed at the beginning of the 20th century.
From this information, they have been able to observe the evolution of this species. "As climate change altered habitats, species left some areas and moved to others, taking the virus with them. This not only modified the regions where viruses are present but most likely allowed new interactions between animals and viruses, which caused more harmful viruses to be transmitted or evolve," the expert comments.
Up to 60% of emerging infectious diseases worldwide are zoonoses, i.e. they originate and are transmitted by animal mechanisms and can reach humans. In reference to this fact, bats are one of the main transmitters among mammals.
The total population of this species carries about 3,000 different types of coronaviruses, and each of them is estimated to carry 2.7 coronaviruses, although most of them are asymptomatic. This is why such a large-scale increase in their population could increase the likelihood of a COVID appearing for the human species.
"The COVID-19 pandemic has caused tremendous social and economic damage. Governments must seize the opportunity to reduce the health risks of infectious diseases by taking decisive action to mitigate climate change" comments Andrea Manica, Professor in the Department of Zoology at the University of Cambridge.