Page 245 - Microbial methane cycling in a warming world From biosphere to atmosphere Michiel H in t Zandt

laboratory cultures of relevant microorganisms. It is important to both understand how microorganisms contribute to climate change and how they, in turn, will be affected by climate change and human activities (Cavicchioli et al. 2019).
Microbiologists have an important part to play in current and future climate research, as well as the climate debate. Interdisciplinary workgroups and organizations like the NESSC fulfill an important role in unraveling current environmental challenges. In addition, the scientific community needs to create a platform in which concerns about human-induced climate change can be voiced. The local and global initiatives of Scientists4Future provide such a medium (Scientists4Future NL 2020). Over the last six years I have been involved in both scientific and societal projects regarding the impacts of a warming world. The results of the scientific discoveries and societal discussions are presented in this thesis. To appropriately emphasize both areas, this integration and outlook includes both a scientific and a societal section.
Part A: Scientific integration and Outlook
Methane is a major anthropogenic GHG, second only to CO2 (Myhre et al. 2013). Its climate feedbacks and mechanisms are multilayered and highly complex (Fig. 1). In a world that is rapidly changing due to human activity, atmospheric CH4 concentrations have more than doubled compared to the average over the last 800,000 years. The accelerating methane growth rate from 2010 to 2017 is linked to contributions from tropical wetlands (~35 %), anthropogenic emissions in China (~20 %), and northern regions that include large natural gas fields (~15 %) (Yin et al. 2020). Such a strong atmospheric growth rate has not been observed since the 1980s. It is strongly linked to human activities and corresponds to record peaks in total global CH4 emissions.
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