Sunday 8 January 2023

STATE OF PLAY: By 2022 the Earth was an est. 1.14°C hotter than its pre-industrial era average. Australian had warmed on average by 1.47 ± 0.24 °C since national records began in 1910. WHO warns that global heating of even 1.5°C is not considered safe & every additional tenth of a degree of warming will take a serious toll on people’s lives and health.

 

World Health Organisation, Climate change and health, excerpts, 30 October 2021:


The Intergovernmental Panel on Climate Change (IPCC) has concluded that to avert catastrophic health impacts and prevent millions of climate change-related deaths, the world must limit temperature rise to 1.5°C. Past emissions have already made a certain level of global temperature rise and other changes to the climate inevitable. Global heating of even 1.5°C is not considered safe, however; every additional tenth of a degree of warming will take a serious toll on people’s lives and health......


Climate-sensitive health risks


Climate change is already impacting health in a myriad of ways, including by leading to death and illness from increasingly frequent extreme weather events, such as heatwaves, storms and floods, the disruption of food systems, increases in zoonoses and food-, water- and vector-borne diseases, and mental health issues. Furthermore, climate change is undermining many of the social determinants for good health, such as livelihoods, equality and access to health care and social support structures. These climate-sensitive health risks are disproportionately felt by the most vulnerable and disadvantaged, including women, children, ethnic minorities, poor communities, migrants or displaced persons, older populations, and those with underlying health conditions.




Figure: An overview of climate-sensitive health risks, their exposure pathways and vulnerability factors. Climate change impacts health both directly and indirectly, and is strongly mediated by environmental, social and public health determinants.



Although it is unequivocal that climate change affects human health, it remains challenging to accurately estimate the scale and impact of many climate-sensitive health risks. However, scientific advances progressively allow us to attribute an increase in morbidity and mortality to human-induced warming, and more accurately determine the risks and scale of these health threats.


In the short- to medium-term, the health impacts of climate change will be determined mainly by the vulnerability of populations, their resilience to the current rate of climate change and the extent and pace of adaptation. In the longer-term, the effects will increasingly depend on the extent to which transformational action is taken now to reduce emissions and avoid the breaching of dangerous temperature thresholds and potential irreversible tipping points.



NatureClimate change is making hundreds of diseases much worse, excerpt, 12 August 2022:


Climate change has exacerbated more than 200 infectious diseases and dozens of non-transmissible conditions, such as poisonous-snake bites, according to an analysis. Climate hazards bring people and disease-causing organisms closer together, leading to a rise in cases. Global warming can also make some conditions more severe and affect how well people fight off infections.


Most studies on the associations between climate change and disease have focused on specific pathogens, transmission methods or the effects of one type of extreme weather. Camilo Mora, a data scientist at the University of Hawaiʻi at Mānoa, and his colleagues scoured the literature for evidence of how ten climate-change-induced hazards — including surging temperatures, sea level rise and droughts — have affected all documented infectious diseases (see ‘Climate hazards exacerbate diseases’). These include infections spread or triggered by bacteria, viruses, animals, fungi and plants (see ‘Mode of transmission’). The study was published in Nature Climate Change on 8 August.


The study quantifies the many ways in which climate change affects human diseases, says Mora. “We are going to be under the constant umbrella of this serious threat for the rest of our lives,” he adds.


Literature review


Mora and his colleagues examined more than 77,000 research papers, reports and books for records of infectious diseases influenced by climatic hazards that had been made worse by greenhouse-gas emissions. More than 90% of the relevant papers had been published after 2000. Ultimately, the team found 830 publications containing 3,213 case examples.


The researchers discovered that climate change has aggravated 218, or 58%, of the 375 infectious diseases listed in the Global Infectious Diseases and Epidemiology Network (GIDEON), and the US Centers for Disease Control and Prevention’s National Notifiable Diseases Surveillance System. The total rises to 277 when including non-transmissible conditions, such as asthma and poisonous-snake or insect bites. The team also identified nine diseases that are diminished by climate change. [my yellow highlighting]


Research paper "Over half of known human pathogenic diseases can be aggravated by climate change" (Mora, C. et al, August 2022) can be accessed at:

https://www.nature.com/articles/s41558-022-01426-1



On the subject of COVID-19…..


World Health Organisation, Zoonoses, excerpt, 29July 2020:


A zoonosis is an infectious disease that has jumped from a non-human animal to humans. Zoonotic pathogens may be bacterial, viral or parasitic, or may involve unconventional agents and can spread to humans through direct contact or through food, water or the environment. They represent a major public health problem around the world due to our close relationship with animals in agriculture, as companions and in the natural environment. Zoonoses can also cause disruptions in the production and trade of animal products for food and other uses.


Zoonoses comprise a large percentage of all newly identified infectious diseases as well as many existing ones. Some diseases, such as HIV, begin as a zoonosis but later mutate into human-only strains. Other zoonoses can cause recurring disease outbreaks, such as Ebola virus disease and salmonellosis. Still others, such as the novel coronavirus that causes COVID-19, have the potential to cause global pandemics. [my yellow highlighting]


North Coast Voices readers may have noticed that "zoonoses" are mentioned in "Climate-sensitive health risks" and that zoonoses, as one of the nine categories listed  as such health risks in the graphic insert, are considered to be strongly mediated by environmental, social and public health determinants.


It may be that a potential exists for the SARS-CoV-2 virus to alter its nature in unexpected ways as the climate continues to change. If Australia's response to the virus remains almost entirely politically driven as it has been since the second half of 2021 and does not return swiftly to a predominately science based policy and public health implementation, then any increase in virulence will likely markedly weaken the nation's social and economic bonds. Alternatively, if a new highly infectious zoonosis with significant morbidity emerges and, because our governments and their health agencies have not leant the lessons of the ongoing COVID-19 pandemic, the nation will not be anymore prepared than it was in January 2020.


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