In a new paper published on 18 June in Nature Reviews Microbiology, 30 microbiologists from 9 countries issue a “warning to humanity” (1). According to the authors, climate change is impacting most life on Earth — including microbes.
Human-induced climate change is causing unprecedented animal and plant extinctions leading to huge losses in biodiversity, the authors write. In this so-called Anthropocene — the era we now live in — the authors urge the world to stop ignoring this ‘unseen majority’ when addressing climate change.
The international effort, led by Prof Rick Cavicchioli, of the University of New South Wales in Sydney, Australia, provides some compelling evidence for why microbes should be included in climate change research. Furthermore, they argue research should be integrated into frameworks for addressing climate change and accomplishing the United Nations Sustainable Development Goals.
“Our Consensus statement represents a warning to humanity from the perspective of Microbiology”, they write. The authors are part of the alliance of world scientists and the scientists’ warning movement was established to alert humanity to the impacts of human activities on global climate and the environment.
The researchers hope their paper will help spread knowledge and awareness about microbes — both how they are affected by it and how they can influence it. In addition, they are developing new educational materials to educate students about the importance of microbes.
Microorganisms, such as bacteria and viruses, are a crucial part of the Earth’s biodiversity and ecosystems. Vast numbers of teeny tiny organisms “support the existence of all higher lifeforms and are critically important in regulating climate change,” says Cavicchioli, “however, they are rarely the focus of climate change studies and not considered in policy development.” Adding that, “Climate change is literally starving ocean life”.
The crucial role of microbes
Microbes play a critical role in functions related to animal and human health, agriculture, and food security. According to the Census of Marine Life, microbes make up more than 90 per cent of the ocean’s total biomass.
In the ocean, tiny phytoplankton is the starting point of the marine food web, providing food for krill that are gobbled up by larger fish, sea birds, and mammals. These ocean microbes also absorb energy from the sun and remove more carbon dioxide from the air than plants. And in colder arctic climates, melting sea ice and declining glaciers are affecting sea ice algae, which will also affect the oceanic food chain.
On land, microbes release large amounts of greenhouse gases, including carbon dioxide and methane, that are released into the atmosphere, including microbes living in the rumen of farm animals. And climate change is increasing these emissions thereby further affecting global warming.
The authors argue that by not considering microbial contributions effectively, predictions of climate models may be inaccurate since microbes present a huge part of the picture. For this reason, they suggest climate change research must place more of an emphasis on microbial processes and how they affect biological processes as well as global geophysical and climate processes.
As they write, “Unless we appreciate the importance of microbial processes, we fundamentally limit our understanding of Earth’s biosphere and response to climate change and thus jeopardize efforts to create an environmentally sustainable future.”
(1) Cavicchioli, R. et al. Scientists’ warning to humanity: microorganisms and climate change. Nature Reviews Microbiology (2019). DOI: 10.1038/s41579-019-0222-5
Image: Volvox, a type of chlorophyte green algae that live in freshwater.