Scientists warn that climate change may depend on microbes – Quartz


Microbes literally support all life on Earth. They are the basis of the food chain, no matter where you look, and regulate various critical processes for all of us. They are also the vast majority of life forms on the planet, surpassing all other living beings by astounding amounts. But in the vast majority of cases, we still need to understand how they will be affected by climate change – and how that will affect climate change.

More than 30 microbiologists signed a statement published in Nature Reviews Microbiology yesterday (June 19) with the intention of putting "humanity on alert" about the risk of ignoring these tiny creatures. In the statement, entitled "Scientists warn humanity: microorganisms and climate change," they write that "the microscopic majority can no longer be the invisible elephant in the room."

Ricardo Cavicchioli, a microbiologist at the University of New South Wales in Sydney, Australia, and author of the statement, also wants to raise what he calls "microbial literacy," as well as just scientists and policymakers. He thinks children should be learning about these crucial life forms, even in kindergarten. "When you tell people:" Where does most of the oxygen come from? ", Most people understand that it is from plants," but they have no idea that the microbes that inhabit the oceans are responsible for about half of the world's oxygen production. for example. He and his colleagues are part of an initiative to develop a microbiology curriculum for "pre-school to high school" classrooms to try to fill those gaps.

The microbial world is "the life support system of the biosphere," writes Cavicchioli and his co-authors in the consensus statement. All other organisms depend on them. This means that changes in their diversity, abundance, or ability to continue to function in the way they have so far can have consequences far beyond their tiny forms.

It's not just that microbes will be affected by climate change. Microbes serve as digesters of greenhouse gases, and also produce greenhouse gases, so it happens in both directions.[T]The impact of climate change will depend heavily on the responses of microorganisms, "they write," they are rarely the focus of climate change studies and are not considered in policy development. " Climate models – and therefore the global response to climate change – are incomplete without them.

The "invisible majority"

Microbes are microscopic creatures. They include bacteria, viruses, phytoplankton and virtually everything else that can not be seen with the naked eye. Their populations are unimaginably large; there are 100 million times more bacteria in the oceans than stars in the known universe, for example, and represent 95% of the total mass of ocean creatures. There are about a billion microbes in any teaspoon of soil. If all the virus microbes on Earth were put end to end, they would extend for 100 million light-years.

The instagram pondlife_pondlife account, where microbiologist Sally Waring collects microbes (you guessed it) and puts videos of them under the microscope, gives you an idea of ​​just how active these life forms can be.

Like any other plant or animal, microbes will – and already are – affected by climate change. "Climate change disrupts interactions between species and forces species to adapt, migrate and be replaced by others or become extinct," write microbiologists, and that includes microbes. The impact of these changes is still poorly understood, but will be critical to life on the planet.

Soil microbes, for example, play a large role in cycling nutrients and entrapment and release of greenhouse gases, but how climate change affects such processes is difficult to determine without extensive dedicated research, as each soil hosts numerous radically different microbes all interacting with each other and impacted by many factors.

In the ocean, microbes literally determine the effect of greenhouse gases on climate change. Microbes break down organic material, such as dead fish or plant matter, and in doing so release carbon dioxide back into the atmosphere. They also play a role in blocking carbon dioxide in the seabed dying and being buried, which is crucial in keeping that source of greenhouse gas from reaching the atmosphere.

At sea, phytoplankton accounts for 50% of all photosynthesis, a process most popularly associated with plants that extract carbon dioxide from the environment and release it as oxygen. Changes in climate can greatly alter this process – but the lack of long-term phytoplankton data makes it difficult to say for sure how they could impact this massive global process, according to the statement.

Meanwhile, in sea ice, specially adapted algae grow on mats, creating a brown layer on the ice. "They fix carbon dioxide using solar energy. Therefore, if sea ice is decreasing, we know that the growth capacity of seaweed is decreasing. That means they are taking less CO2 out of the air, "says Cavicchioli.

Viruses are also microbes and are spreading with climate change. Mosquitoes, such as dengue, zika and yellow fever, are expanding their ranges northward as the planet warms. As winters become more resistant to tropical mosquito species and the microbes they carry, "millions of people are at risk of further climate change," write microbiologists. Again, microbes are at the heart of these changes.


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