Jesus M. Castillo, Professor of Ecology at the University of Seville, contributes a second article analysing the coronavirus crisis from an ecological standpoint.
The global ecological crisis is one of the main causes of the Covid-19 coronavirus health crisis . Specifically, of the many socio-environmental problems that make up the ecological crisis, those that are most directly related to the current health crisis are deforestation and the destruction of biodiversity.
In recent decades, infectious disease outbreaks have been increasing from close to 20 events in the 1940s to over 70 in the 1980s, 1990s, and the first decade of the 21st century. The majority (60%) of these outbreaks were from diseases transmitted from other animals to humans ( zoonosis ) and, in turn, the majority (72%) of these zoonosis outbreaks originated in wildlife. Recent examples of zoonoses from wildlife include outbreaks of the Human Immunodeficiency Virus (HIV), Ebola, Severe Acute Respiratory Syndrome (SARS), and Covid-19. Outbreaks of mosquito-borne infectious diseases, such as dengue, yellow fever, and malaria, and ticks, such as Lyme disease, are also on the rise.
Deforestation, biodiversity and infectious diseases
Several studies have shown that the increase in outbreaks of infectious diseases is due, in large part, to deforestation . The loss of forest stands, together with the occupation of the areas deforested by human infrastructures, make it easier for infectious agents to reach Homo sapiens ; remember that the human being is another animal in ecosystems. For example, the appearance of Ebola outbreaks is associated with the degradation and destruction of tropical forests that force bats to inhabit gardens and farms.
One of the direct consequences of deforestation is the disappearance of animal and plant species. The loss of biodiversity also favors the appearance of infectious outbreaks. Biodiversity prevents many pathogens from reaching the human being, in what is known as the Dilution Effect. For example, there are predators that feed on infected animals, other species that parasitize human parasites (hyper-parasitism), others that act as false decoys for parasites, others that become infected by diluting the parasite load among various species, other species that they act as physical barriers to the spread of parasites… In other words, biodiversity weaves a complex web of life that reduces the transmission of infectious diseases. Natural ecosystems fulfill many services that they offer us for free, whether they are provisioning, cultural or regulatory. One of these regulatory ecosystem services is to control the spread of pathogens.
Agro-industrial system and infectious diseases
The industrial livestock system also favors the appearance of outbreaks of infectious diseases . For example, Avian Influenza viruses (eg H5N1), transmitted from waterfowl, pass to chicken factory farms where it can mutate and become more virulent. In addition, the Nipah virus outbreak (Malaysia, 1998) was due to the installation of intensive pig farms next to deforesting tropical forests, habitats of bats that host the virus. Animals are stressed, overcrowded, with low defenses, highly exposed to pathogens on factory farms.
In addition, the expansion of intensive farming and ranching is one of the main responsible for deforestation in inter-tropical zones. On the other hand, animal species that never interact in their natural environment are caged together in markets , facilitating the transmission of pathogens. This was the origin of the SARS coronavirus epidemic in 2002-2003, and could also be the origin of the Covid-19 pandemic.
Wuhan and Chinese rural exodus
Wuhan, the Chinese city where the Covid-19 pandemic originated, went from being a city of about 2 million inhabitants, in the early 1980s, to currently having about 8 million inhabitants. This growth was mainly concentrated in the 1990s, in which a large metropolitan area was born, invading rural and natural areas of forests and lakes. Along with Wuhan, many other metropolises have grown in China and many other, especially impoverished, countries in recent decades.
The Greater Wuhan Metropolitan Area, similar in size to London, attracted millions of peasant families with a culture closely related to nature . These cultural practices, which include, for example, the consumption of certain wild animals, occur very differently in small, more or less isolated urban enclaves than in a large metropolis. The metropolis favors a huge consumption of wild animals and their overcrowding. Furthermore, once zoonosis occurs, the infection spreads much more quickly in the big city, especially when it is connected internationally in a scenario of capitalist globalization.
Life is reborn now in the big cities now paralyzed by the health alert. The birds occupy the streets, the canals of Venice reveal the fish in its crystalline waters, the vegetation colonizes… Some initial changes that offer us an idea of a horizon of green cities and friendly to its inhabitants.
Back to normal”? No thanks!
As scientific studies show us, the same deforestation that favors climate change leads to large losses of biodiversity and the spread of infectious diseases to humans. Furthermore, the industrial agri-food system, which favors this deforestation and climate change, also drives the spread of infectious diseases. Although the increase in temperatures due to climate change could decrease the transmission of some viral infectious diseases, it increases the spread of other diseases with mosquitoes as vectors. Furthermore, climate change-related pollution can increase the severity of some infectious respiratory diseases such as Covid-19.
It is also important to highlight that climate change affects more working people, and small farmers and entrepreneurs, in rich countries and, especially, in impoverished countries. Those who have less adaptation possibilities suffer more. This same social vulnerability, which is so socially and geographically differentiated, applies equally to infectious diseases.
The internationally organized socio-economic slowdown to fight Covid-19 is showing that greenhouse gas emissions can be dramatically curbed in a coordinated manner, while many other socio-environmental impacts are diminished. The current health crisis takes place in a global ecological crisis that is one of its main causes. Furthermore, another cause of the Covid-19 pandemic is the globalized capitalist socio-economic system that has favored its expansion. A capitalist system that, in turn, is the main cause of the global ecological crisis and the climate emergency. Returning to the “business as usual”, to the “normality” before the Covid-19 pandemic would be a catastrophe.
The challenges of the current health crisis, which must paralyze the economy on an international scale to slow contagion and save lives, force us to develop anti-capitalist alternatives . We have to strengthen and extend the health, education and other universal public services systems at the international level. Key sectors of the economy must be nationalized under workers control. We have to distribute wealth to finance public services, to rescue workers and small farmers and entrepreneurs, to support impoverished countries for environmental and health justice. This distribution of wealth together with leaving behind capitalist competition would promote an economic decrease in rich countries that would improve the quality of life in all territories.The Covid-19 health crisis is an opportunity to rethink our relationship with nature in depth .
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