The Zika ThreatThe infection is suspected of leading to thousands of babies being born with underdeveloped brains.
It is difficult to imagine two fields more different in their methods, tools, and objectives than climate science and microbiology, and yet there is a vital connection between these two endeavors. Microbes are critical players in every geochemical cycle relevant to climate including carbon, nitrogen, sulfur, and others. The sum total of microbial activity is enormous, but the net effect of microbial activities on the concentration of carbon dioxide and other climaterelevant gases is currently not known. The past two decades have witnessed an explosion in our recognition of the diversity of the microbial world, as new technologies have made it possible to characterize microbial communities in ever greater detail. Modeling, too, has experienced tremendous advances in its capabilities. For all the progress, however, we are not able to measure microbial processes in such a way as to allow climate scientists to include them in models of global climate.
Determining how to measure the rates, fates, and fluxes of climate-relevant gases through microbial communities and the environment is a task that falls between climate science and microbiology and is the focus of neither. While the gap between the two disciplines is daunting, the need to bridge it is urgent and the science and technology needed to begin to do so is within reach. By breaking the task down into tractable parts, strategically developing needed tools, methods and community resources, and facilitating the establishment of interdisciplinary teams with welldefined, shared goals, the task of incorporating microbial processes into climate models can begin to be tackled, to the benefit of both fields.
The differences between climate science and microbiology are considerable, but they have something quite powerful in common, the use of models. Indeed, both Earth’s climate and microbial community processes are too complex to study without models. In both fields, models represent logical syntheses of assumptions and boundary conditions, can identify gaps in understanding, and are useful for revealing amplification and dampening effects. The development of methods to quantify microbial impacts on climate so that they can be incorporated into climate models is a major interdisciplinary challenge.
Connecting the pieces:
For the first time, an accurate, quantitative census of microbes inhabiting any environment can now be taken. Knowing which microbes are present is useful for suggesting the community potential, what processes might be going on now, or might be possible in other circumstances, but that information cannot yet be turned into fluxes and rates. The challenge will be to simplify complex community dynamics so that net inputs and outputs that accurately reflect reality can be incorporated into climate models.
The group recommended a multi-pronged approach to breaking the challenge into manageable parts.
Major events of the distant past illustrate the need to incorporate microbial activities into existing climate models. They demonstrate that the microbial processes that affect climate do not necessarily balance each other out. Billions of years ago, changing microbial community composition resulted in the shift to an oxygenated atmosphere. The organisms that had inhabited the Earth for at least a billion years were no longer able to survive on the Earth’s surface. In the past, such profound change took millions of years, a time span well beyond that with which current climate models are concerned. Today, changes due to human activity are causing similar large scale global effects in as little as 100 years. There is clear evidence that microbes can have an enormous impact on climate but their responses and impacts cannot currently be measured. In light of ongoing global change and the centrality of microbes in global biogeochemical cycles, their specific responses and activities in the context of climate change modeling can no longer be ignored.