How will climate change affect us?
- The cost of pandemics is measured in multiple ways: lives lost, health care systems over-strained, mental and physical well-being, and economies in tatters.
- Information on this page is extracted directly from the 2020 IBES report on the relationship between pandemics, biodiversity, and climate change. The full report is here.
” There is no great mystery about the cause of the COVID-19 pandemic – or of any modern pandemic. The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on our environment. Changes in the way we use land; the expansion and intensification of agriculture; and unsustainable trade, production and consumption disrupt nature and increase contact between wildlife, livestock, pathogens and people. This is the path to pandemics.” -Peter Daszak, President of EcoHealth Alliance and Chair of the IPBES workshop.
IPBES Workshop on Biodiversity and Pandemics (direct extract)
“The overwhelming scientific evidence points to a very positive conclusion,” said Dr. Daszak. “We have the increasing ability to prevent pandemics – but the way we are tackling them right now largely ignores that ability. Our approach has effectively stagnated – we still rely on attempts to contain and control diseases after they emerge, through vaccines and therapeutics. We can escape the era of pandemics, but this requires a much greater focus on prevention in addition to reaction.
“The fact that human activity has been able to so fundamentally change our natural environment need not always be a negative outcome. It also provides convincing proof of our power to drive the change needed to reduce the risk of future pandemics – while simultaneously benefiting conservation and reducing climate change.”
Pandemics emerge from the microbial diversity found in nature
- The majority (70%) of emerging diseases(e.g. Ebola, Zika, Nipah encephalitis), and almost all known pandemics (e.g. influenza, HIV/AIDS, COVID-19), are zoonoses – i.e. are caused by microbes of animal origin. These microbes ‘spill over’ due to contact among wildlife, livestock, and people.
- An estimated 1.7 million currently undiscovered viruses are thought to exist in mammal and avian hosts. Of these, 540,000-850,000 could have the ability to infect humans.
- The most important reservoirs of pathogens with pandemic potential are mammals (in particular bats, rodents, primates) and some birds (in particular water birds), as well as livestock (e.g. pigs, camels, poultry).
Human ecological disruption, and unsustainable consumption drive pandemic risk
- The risk of pandemics is increasing rapidly, with more than five new diseases emerging in people every year, any one of which has the potential to spread and become pandemic. The risk of a pandemic is driven by exponentially increasing anthropogenic changes. Blaming wildlife for the emergence of diseases is thus erroneous, because emergence is caused by human activities and the impacts of these activities on the environment.
- Unsustainable exploitation of the environment due to land-use change, agricultural expansion and intensification, wildlife trade and consumption, and other drivers, disrupts natural interactions among wildlife and their microbes, increases contact among wildlife, livestock, people, and their pathogens and has led to almost all pandemics.
- Climate change has been implicated in disease emergence (e.g. tick-borne encephalitis in Scandinavia) and will likely cause substantial future pandemic risk by driving movement of people, wildlife, reservoirs, and vectors, and spread of their pathogens, in ways that lead to new contact among species, increased contact among species, or otherwise disrupts natural host-pathogen dynamics.
- Biodiversity loss associated with transformation of landscapes can lead to increased emerging disease risk in some cases, where species that adapt well to human-dominated landscapes are also able to harbour pathogens that pose a high risk of zoonotic transmission.
- Pathogens of wildlife, livestock and people can also directly threaten biodiversity, and emerge via the same activities that drive disease risk in peopl (e.g. the emergence of chytridiomycosis in amphibians worldwide due to the wildlife trade).
Reducing anthropogenic global environmental change may reduce pandemic risk
- Pandemics and other emerging zoonoses cause widespread human suffering, and likely more than a trillion dollars in economic damages annually. This is in addition to the zoonotic diseases that have emerged historically and create a continued burden on human health. Global strategies to prevent pandemics based on reducing thewildlife trade and land-use change and increasing One Health1 surveillance are estimated to cost between US$22 and 31.2 billion, reduced even further (US$17.7-26.9 billion) if benefits of deforestation on carbon sequestration are calculated – two orders of magnitude less than the damages pandemics produce.
- The true impact of COVID-19 on the global economy can only be accurately assessed once vaccines are fully deployed and transmission among populations is contained. However, its cost has been estimated at US$8-16 trillion globally by July 2020 and may be US$16 trillion in the US alone by the 4th quarter of 2021 (assuming vaccines are effective at controlling it by then).
- Pandemic risk could be significantly lowered by promoting responsible consumption and reducing unsustainable consumption of commodities from emerging disease hotspots, and of wildlife and wildlife-derived products, as well as by reducing excessive consumption of meat from livestock production.
- Conservation of protected areas, and measures that reduce unsustainable exploitation of high biodiversity regions will reduce the wildlife-livestock-human contact interface and help prevent the spillover of novel pathogens
Land-use change, agricultural expansion, and urbanization cause more than 30% of emerging disease events
- Land-use change is a globally significant driverof pandemics and caused the emergence of more than 30% of new diseases reported since 1960.
- Land-use change includes deforestation, human settlement in primarily wildlife habitat, the growth of crop and livestock production, and urbanization.
- Land-use change creates synergistic effects with climate change (forest loss, heat island effects, burning of forest to clear land) and biodiversity loss that in turn has led to important emerging diseases.•Destruction of habitat and encroachment of humans and livestock into biodiverse habitats provide new pathways for pathogens to spill over and increase transmission rates.
- Human health considerations are largely unaccounted for in land-use planning decisions.•Ecological restoration, which is critical for conservation, climate adaptation and provision of ecosystem services, should integrate health considerations to avoid potential increased disease risk resulting from increased human-livestock-wildlife contact.
References and further reading
- 2020: Intergovernmental Council on Pandemic Prevention: Addressing risk drivers
- 2020: DOC; Biodiversity in Aotearoa: an overview of state, trends and pressures Department of Conservation
- 2020: Gibb et al; Zoonotic host diversity increases in human-dominated ecosystems Nature 584 pp398–402
- 2020: (Nature article explaining the above research) Toll; Why deforestation and extinctions make pandemics more likely
- 2020: Joy; NZ’s polluted waterways threaten our health, Newsroom 04 June
- 2020: The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES): Global Assessment Report on Biodiversity and Ecosystem Services
- 2019: Diaz et al; Summary for policymakers of the global assessment report on biodiversity and ecosystem services, Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.