The frequency with which new, serious disease epidemics have been occurring is briefly mentioned, also in light of climate change, and climate and other pathogens.

Columbia University State of the Planet (2014), Renee Cho wrote: [Generally], when it’s warmer, the disease transmission system speeds up.

Some scientists think that climate change, with its increase in sudden and extreme weather events, plays a role in Ebola outbreaks: dry seasons followed by heavy rainfalls that produce an abundance of fruit have coincided with outbreaks. When fruit is plentiful, bats (the suspected carriers of the recent Ebola outbreak) and apes may gather together to eat, providing opportunities for the disease to jump between species. Humans can contract the disease by eating or handling an infected animal.

According to the United States Agency for International Development, “nearly 75 percent of all new, emerging, or re-emerging diseases affecting humans at the beginning of the 21st century are zoonotic” — meaning they originate in animals. These include AIDS, SARS, H5N1 avian flu and the H1N1 flu. More and more wild animals, which may have carried diseases without effect for years, are coming into contact with humans, often because of deforestation.

National Geographic, January 21st, 2020:

SARS and the new virus behind the Wuhan outbreak are highly related, both belonging to a family called coronaviruses. Coronaviruses are a large family of viruses, some of which cause illness in people, while others circulate among animals, including camels, cats, and bats. [..] Global surveys would ultimately reveal that the ancestors and relatives of SARS had been circulating in bats across Asia, Africa, and Europe for years. Bats are now considered the original source of all major coronaviruses.

Andreas Kluth writes for Bloomberg January 21st, 2020:

For one thing’s certain: the next pandemic will come, and it may resemble the Spanish flu of 1918, which infected half a billion people. The questions are when, where and how, and whether we’ll be ready collectively. I say “collectively” because a pandemic, like climate change, doesn’t respect passports or borders. We don’t quarantine, cure or save America First, or China First or anybody first; we either put humanity first or we all lose.

There are other links between climate change and pandemics (and, to be clear, the current outbreak is still far from being one). The main connection is that global warming actually creates new disease vectors. As the permafrost thaws in places like Siberia, viruses that have been frozen for millennia, and against which animals and humans no longer have any resistance, will resurface. And as desertification and other side effects of warming move the boundaries between habitats, species will come into contact with creatures they’ve never encountered before. That’s how viruses start their journey.

Resurfacing of pathogens is a very real scenario, for instance consider the 2016 Russian Anthrax incident

• Dead for 32,000 Years, an Arctic Plant Is Revived
• Worms Frozen for 42,000 Years in Siberian Permafrost Wriggle to Life
• Russian Scientists Find Liquid Blood in Extinct Siberian Foal Dating Back 42K Years
• Meet the Scientist Who Injected Himself with 3.5 Million-Year-Old Bacteria
• Frozen Giant Virus Still Infectious After 30,000 Years

CLIMATE STATE noted in 2013:

Rachel Kyle, the World Bank’s vice president for sustainable development, told The Independent: We expect to see more outbreaks of unknown pathogens [disease-causing micro-organisms] as temperatures and weather patterns change.

Not just new pathogens

There are many agents connected to climate warming, and which could pose a threat, weaken organism immune systems, lowering the potential to withstand disease. One of such is mercury, it accumulated in past decades in frozen soils, now induced thaw could once again mobilize it – end up in our food chain.

Related to human health are also artificially created ‘forever chemicals,’ with immunotoxicity. The Guardian noted this week, ‘US drinking water contamination with ‘forever chemicals’ far worse than scientists thought.’ And this forever chemical is a carcinogenic – again reducing organism odd’s of surviving a pathogen exposure.

The take away here is that new disease vectors could occur more frequent in a warming world, currently we see the novel Wuhan coronavirus emerge, as well as a possible rise in incidents of increased overall background exposure to pathogens.

The result means more frequent interruptions for societies, our collective ability to function properly, during a time when people need to learn and stem climate actions, and to plan, and implement forced adaptations.

Vector-borne diseases

ClimateNexus, ‘Climate risk and spread of vector-borne diseases’:

Rising global temperatures can lengthen the season and increase the geographic range of disease-carrying insects. As temperatures warm, mosquitoes and other warm-weather vectors can move into higher altitudes and new regions farther from the equator. For instance, in some regions in the United States, warming is lengthening the the season for Zika-carrying mosquitoes.

Increased rainfall, flooding and humidity creates more viable areas for vector breeding and allows breeding to occur more quickly, as eggs hatch faster in hotter climates. For example, officials braced for an increase in risk for Zika and West Nile virus infections after the massive flooding event in Louisiana in August 2016, which increased the breeding habitats for Aedes mosquitoes.

Human migration exposes people to viruses to which they are not immune. As populations migrate in response to climate change, they bring disease to new regions and urban areas. Infectious diseases spread more quickly in overcrowded urban areas.

While our ability to control exposure to a new virus is limited, our decision to stop burning fossil fuels has an immediate effect on the air we breath, same with the end to stop polluting our environment with plastic, or ending the trashing of the atmosphere with heat trapping chemistry.

Teaser image: Larger than some bacteria, this Pithovirus — seen in a cross-section under a transmission electron microscope — was still able to infect amoebae despite having spent 30 millennia in a frozen state.  https://www.nature.com/news/giant-virus-resurrected-from-30-000-year-old-ice-1.14801

Related

• Inside China’s leading ‘sponge city’: Wuhan’s war with water, ‘Wuhan was once known as “the city of a hundred lakes”. It had 127 lakes in its central area alone in the 1980s, but decades of rapid urbanisation mean only around 30 survive.’ https://www.theguardian.com/cities/2019/jan/23/inside-chinas-leading-sponge-city-wuhans-war-with-water