The catastrophic loss of biodiversity, the Luck destruction of the wilderness and the rise in temperature caused disease outbreaks. One scientist said it would be "dangerous delusions" to ignore the link between climate change and epidemics.
Scientists studying how diseases occur in a changing environment know that this moment is coming. Climate change has made disease outbreaks more common and more dangerous.
Over the past few decades, the number of emerging infectious diseases (especially coronaviruses and other respiratory diseases, believed to be from bats and birds) that have spread to people has surged. . There are five emerging diseases every year. A study estimated that over 3200 coronaviruses already exist between bats, waiting for the opportunity to jump to people.
This disease may persist and be buried deep in wild and remote areas that people cannot reach. But until now, the Earth's natural defense system has been better at countering it.
Today, climate warming is destroying these defense systems, causing catastrophic losses of biodiversity, coupled with Lure ’s deforestation and the conversion of savage lands into economic development
Harvard University TH-C-Climate, Aaron Bernstein, the interim director of the Center for Health and Global Environmental Change, said the School of Public Health, ignoring how the rapid development of climate and land oppresses disease-bearing animals, is like playing Russian roulette.
"Nature is trying to tell us something," Bernstein said.
Scientists did not imply that climate has any direct role in causing the current COVID-19 outbreak. Although the virus is thought to have originated from horseshoe bats, part of the genus has roamed the earth ’s forests for 40 million years and has grown in remote jungles in southern China. It is even uncertain.
However, the Coronaviruses in southern China have been studied for many years and warned that rapid climate and environmental changes in the region (including biodiversity loss and civilization invasion) will help spread new viruses to people.
There are three ways in which climate affects emerging diseases. Approximately 60% of new pathogens come from animals-including animals that are stressed due to loss of diversity-approximately one third can be directly attributed to changes in human land use, which means deforestation, agricultural introduction, development or natural resource development Settings. Vector-borne diseases (disease carried by insects such as mosquitoes and ticks and transmitted in the blood of infected persons) are also increasing because of warmer weather and unstable rainfall, which greatly expands the geographical area vulnerable to infection. The climate has even recovered old viruses from death and thawed zombie infectious diseases such as anthrax released from frozen reindeer in 2016. This infectious disease may come down from the Arctic and bother us in the past.
Therefore, even if the COVID-19 pandemic occurs, even when it appears in the form of an emergency crisis, it provides a greater lesson. It shows the immense and undeniable power of nature over civilization and even its politics in real time. This alone may become the prelude to a pandemic to make far-reaching and destructive changes. However, it also clearly shows that today ’s climate policy is inseparable from efforts to prevent new outbreaks of infectious diseases, or, as Bernstein said, the notion that climate, health, and environmental policies may not be related is “dangerous delusion”.
Climate warming is one of the main drivers of the largest (and fastest) loss of species diversity in the history of the earth, because changes in climate patterns force species to change their habitats, push them to new areas or threaten their food And water consumables. The so-called biodiversity is crucial, because the natural diversity of plants and animals gives each species greater resistance to threats, and together provides a delicate and balanced safety net for natural systems. As diversity diminishes and balance is broken, the remaining species are more susceptible to human influence, and, according to a landmark study in Nature in 2010, it is more likely to spread powerful pathogens.
The relentless destruction of civilization has exacerbated casualties into forests and wilderness, looking for wood, farmland and other natural resources. Epidemiologists who trace the root causes of disease in South Asia understand that even the incremental and seemingly manageable damage to the local environment (for example, the construction of a pasture near a compressed natural forest) can have huge consequences.
Worldwide, according to data from the World Resources Institute, only 15% of the forest on earth is intact. The rest are felled, degraded or broken, so that they destroy the natural ecosystems that depend on them. As forests have dried up, grasslands and wetlands have also been destroyed, and biodiversity has declined sharply. The United Nations warned that the number of species on the planet has been reduced by 20%, and now more than one million animal and plant species are facing extinction.
In some cases, the loss of species directly leads to an increase in infectious diseases. disease.
In recent years, as the diversity of migratory birds has declined and the threat of West Nile encephalitis has spread, Americans have experienced this phenomenon directly. Facts have proved that birds with this disease are also very common when the population is reduced. Those survivors support the higher infection rate of mosquitoes and spread it to people more.
Similarly, a study published last month in the Journal of the Royal Society found that larger mammals decline or shift as they are attacked by hunters or loggers. Climate patterns, smaller species including bats, rats and other rodents are booming because they are more resilient to degraded environments or they can live better among people.
It is these small animals that are the animals that look for food in trash cans or build nests in the eaves of buildings. Facts have proved that they are most suitable for human interference and may also spread diseases. The researchers found that rodents alone accounted for more than 60% of all diseases transmitted from animals to humans.
The warmer temperatures and higher rainfall associated with temperature changes-coupled with the loss of predators-will surely make the rodent problem worse and have catastrophic effects. For example, in 1999, rainfall in parts of Panama was three times higher than usual. The researchers found that the number of rats increased dramatically. Viruses carried by mice will follow, and these viruses will also jump to people. According to the report of "Emerging Infectious Diseases" magazine
in the same year, Panama had the first fatal lung disease transmitted through the saliva, feces and urine of rats and mice, called Hantavirus pulmonary syndrome. Changes cause species changes, so do changes in the landscape of new farms and new cities. In fact, researchers attribute 30% of emerging infectious diseases to what they call "land use change." Promoting changes in land use is nothing more than the conversion of cultivated land and raw materials, which is the result of promoting food for 7.8 billion people worldwide. In the next 35 years, as the global population surges to 10 billion, and climate warming further emphasizes agricultural production capacity, the demand for land will only increase. Currently, one third of the earth ’s land area and three quarters of all fresh water are used to grow crops and raise livestock. These are the places where infectious diseases spread most frequently.
Take, for example, the Nipah outbreak that broke out in Malaysia in 1999 as an example, which is the real life theme of the movie "Infectious Diseases". Cut down the forest there quickly, paving the way for palm plantations and driving fruit bats to the edge of the trees. (Additional research also shows that climate change is changing the food supply of bats.) They found a place where they live next to a pig farm. When the bats eat fruit, they sprinkle food from the branches along with urine into the pigsty. It is believed that at least one pig ate some. When the pigs were slaughtered and brought to market, it was believed that the person who handled the meat spread an outbreak. More than 100 people died.
The US Centers for Disease Control and Prevention says that three-quarters of all new viruses have come from animals. It is even thought that the 2014 Ebola outbreak in West Africa had begun when a boy was dug into a tree stump that happened to be the habitat of bats carrying the virus.
As an associate director of the Institute of Health, Kristen Johnson, the Interdisciplinary Epidemiology Program at the University of California, Davis states that global health policy makers have a responsibility to understand climate, habitat and land use changes Cause disease. She said that in the past few decades, almost every major epidemic-SARS, COVID-19, Ebola virus and Nipah virus-has jumped from wild animals and plants suffering extreme climate and habitat pressure But, "We are still very naive to them," she said. "This puts us in a dangerous situation."
Once new diseases are lost in our environment, changing temperatures and precipitation are also changing the way these diseases are transmitted, and there is no improvement. Climate warming has increased the range of diseases found, especially through "vectors", mosquitoes and tick-borne diseases, which transmit pathogens from their main hosts to new victims.
In 2008, a study in the journal Nature found that in the past 10 years, one-third of emerging infectious diseases were transmitted by vectors, and jumps coincided with abnormal changes in climate. The study says that especially when insects such as infected mosquitoes are chasing higher temperatures, "climate change may lead to the emergence of diseases."
Now, insects and mosquitoes thrive in places where they have never ventured before. As tropical species move north, they bring dangerous pathogens. Zika virus or Chikungunya is a mosquito-borne virus that exhibits intense joint pain that was not seen in the United States, but has been transmitted locally in southern Texas and Florida in recent years instead of Brought home by travelers.
Soon, they will spread north. According to a 2019 study by PLOS Neglected Tropical Diseases, by 2050, disease-carrying mosquitoes will eventually increase by 500 million people from today, including about 55 million Americans. In 2013, dengue fever (a disease that affects nearly 400 million people each year, but is usually related to the poorest parts of Africa) was first spread locally in New York.
"The long-term risk of dengue fever may be much higher than COVID," said Scott Weaver, director of the Institute of Human Infection and Immunity at the University of Texas Galveston. "This is a disease in poor countries, so it doesn't get the attention it deserves."
The chain of events that ultimately led to the pandemic may be long and subtle, depending on changes in the ecosystem. For example, before the outbreak of the West Nile River in the United States in 1999, climate-driven drought dried up streams and rivers, leaving a stagnant mosquito breeding ground. It turns out that the lost water also killed their natural enemies-dragonflies and frogs that depended on the big puddle disappeared.
Corona viruses like COVID-19 are unlikely to be carried by insects, they will not leave enough infected virus cells in the blood. U.C. said, but one-fifth of other viruses transmitted from animals to humans are vector-borne. Davis ’Johnson means that due to climate warming, it is only a matter of time before other exotic animal-driven pathogens are expelled from global tropical forests to the United States, Canada or Europe. Johnson said: "Climate will turn vulnerability to this point, and I think some of these areas are not ready yet."
The changing climate will affect not only the way disease spreads on the planet, but also how we are on the planet. Easy to get sick. According to a 2013 study in PLOS Currents Influenza, warm winter is the predictor of the worst flu season in the second year. Facts have proved that the short breathing time in the first year relaxes people's natural defense ability and reduces "flock immunity", which lays the conditions for viral revenge.
Even severe fluctuations from hot to cold can be sudden storms-precisely the various climate-induced patterns we have seen-making people more susceptible to illness. A study in the journal Environmental Research Letters linked the brutal 2017-18 flu season (causing 79,000 deaths) to unstable temperature fluctuations and extreme weather in the winter. During the same period, flooding and The hurricane swept the country. The author writes that if the climate crisis continues to develop on its current trajectory, then respiratory infections like influenza will increase dramatically. In this century's most populous city in the United States, the possibility of influenza will increase by as much as 50%, and in Europe, the number of influenza-related deaths may also rise by 50%.
"We are now on a very dangerous road," said Weaver of the University of Texas. He said that slow action on the climate has led to climate warming and inevitable large-scale environmental changes, "and I think the increase in disease will follow."
Ten years before the diagnosis of the first COVID-19 case For two months, it was a group of epidemiologists working with the United States Agency for International Development (PREDICT) or the Pandemic Influenza and other emerging threat projects, hiding deep in the remote dense jungle of Yunnan Province, China, looking for what it considers to be the greatest threat one. Civilization: the source of emerging viruses.
Ten years of research there found a vaguely patterned disease that affected remote villagers, who used bat and bird droppings as fertilizer and sometimes as medicine. Scientists have found dozens of unnamed emerging viruses in caves where horseshoe bats live. Any of them may have caused a global pandemic, killing one million people. However, so far, luck (mostly luck) has prevented the virus from jumping from remote communities to mainstream people.
Since Yunnan is undergoing tremendous changes, luck is likely to be exhausted. Rushing apartment buildings and high-speed rail lines have replaced quaint self-sufficient agricultural land, as the province has experienced dazzling development driven by decades of Chinese economic expansion. The city ’s footprint soared, pushing down the forest. More and more people are moving into rural areas, and the trade in wildlife that is common in these border areas is booming. As the habitat of bats shrinks with every newcomer and every felled tree, the viruses they carry collide with humans. By the end of 2018, epidemiologists began to prepare for what they called "overflow", or because the virus jumped from bats and villages in Yunnan into the wider world and failed to control the virus locally.
At the end of 2018, the Trump administration was part of an extensive effort to stop the US plan in China. The study was suddenly closed and prevented the spread of new coronaviruses. Dennis Carroll, who founded the PREDICT program, said: "We stopped and stopped." He played an important role in global work to deal with the risks posed by emerging viruses. By the end of 2019, the United States Agency for International Development had cut global funding for the program.
The United States Agency for International Development did not answer ProPublica's detailed list of questions.
The loss is huge. The researchers believe that they are on the cusp of the breakthrough, they began to sequence the genes of coronavirus extracted from horseshoe bats, and began to study vaccines. They strive for policy makers for many years to fully consider their understanding of how land development and climate change are driving disease transmission, and they believe their research can literally provide governments with maps of hot spots most likely to cause disease. Next pandemic. They also hope that the genetic material they collect can not only mutate the deadly COVID, but also solve the problem of the entire virus family immediately like a biosphere missile defense system, thereby developing a vaccine. (In fact, the genetic work that they were able to complete was used to test the efficacy of ramcivir, the drug ’s early clinical trial data showed that it could help patients with COVID-19.)
Carroll said that the virus The understanding potential of the genome "completely changes our perception of future biomedical interventions before it appears." His goal is not only to respond to a pandemic, but also to change the definition of disaster preparedness.
If PREDICT's efforts in China have great potential to resist the current COVID pandemic, then it also provides a way to study how to respond. Climate and land development are drivers of disease.
However, there is little demand for policy makers. PREDICT staff and consultants have prompted the US government to consider how combining public health policies with environmental and climate science can help curb the spread of infectious diseases. According to U.C., PREDICT staff mentioned climate change in a speech delivered by Congress. Davis ’s Johnson is now a director of PREDICT and he received a temporary grant this spring. Until 2016, the leaders of the EcoHealth Alliance, a New York research organization funded by PREDICT in Yunnan Province, were repeatedly invited to the White House to provide advice on global health policies.
The organization has not been invited back since Donald Trump was elected.
"This is really refreshing," said Peter Dasak, president of the Eco-Health Alliance.
A White House spokesperson did not respond to a request for comment sent via email.
What Dasak really wants is-in addition to restoring funds to continue his work, the public and leaders should also understand that this is human behavior that is driving the outbreak of disease, just like triggering a climate crisis. In the forests of China, he looked back at the destruction of the trees and asked why the trees had to be felled first, and who would bear the cost. iPhone metal and processed food palm oil are products that stand out from emerging disease hot spots in South Asia and Africa.
"We turn a blind eye to the fact that our actions are driving this," he said. "We get cheap goods through Wal-Mart, and then we always pay for it through the growth of epidemics.