Stringent Northern private food standards have created onerous requirements for horticulture farmers in Kenya who wish to supply global value chains (GVC) and production networks (GPNs) governed by global lead firms. Simultaneously, Southern (regional) supermarkets have emerged over the last few decades leading to the formation of regional production networks (RPNs), which provide a new market opportunity and require meeting different regional private and public standards. Both Northern and regional standards are increasingly including complex environmental requirements that risk farmer exclusion from participation in both global and regional markets. This is exacerbated by bio-physical aspects of climate variability and extremes that impinge on crop quality and yield. A key problem therefore arises from the ability of farmers across not only GPNs but also RPNs and local production networks (LPNs) to cope with different environmental upgrading and downgrading pressures, emerging from standards and bio-physical aspects. The overarching research question this thesis seeks to address is: What are the dynamics of environmental upgrading, embeddedness and governance for farmers in global, regional and local production networks? This thesis seeks to make three contributions to the GPN and GVC literatures. The first is integrating the natural environment through a concept I call re-environmentalization. I suggest farmers dis-embed from previous relationships and interactions with their environment/land and re-embed into new socio-ecological relationships in GPNs, RPNs or LPNs. The second contribution enriches production network and value chain analysis by adding a dimension of Âchanging epistemologiesÂÂ wherein I explicate understandings of governance through the lens of a farmer. I view governance as something that 'is experienced'ÂÂ rather than focus on the lead firms'ÂÂ perspective of 'ÂÂgoverning'ÂÂ. I question the linearity of upgrading, studying what it means to a farmer, instead of assuming that all upgrades are beneficial. The third contribution is to compare how re-environmentalization and governance, effect a farmers' ability to environmentally upgrade heterogeneously across global, regional and local production networks, thereby going beyond the North-South analysis prevalent in GPN literature. The thesis is based on field research in Kenya involving 102 key informant interviews, 6 focus group discussions and a survey of 579 farmers across four counties (Murang'a, Machakos, Nyandarua, Meru) producing snow peas, garden peas, avocados and mangoes. The analysis uses a mixed method approach, drawing on econometric models along with qualitative data to provide triangulated and robust comparisons across production networks. The empirical findings of the research indicate that the trajectories of environmental upgrading/ downgrading are complex and dynamic across farmers in GPNs, RPNs and LPNs. This is because the process through which farmers re-environmentalize into GPNs is contested, as relationships with Northern firms'ÂÂ breed dis-trust and inhibit the use of tacit knowledge. This prevents farmers from performing environmental upgrading in a sustainable way. Furthermore, I debunk the implicit assumption that economically upgrading, by adhering to Northern and regional standards is sustainable, and instead show that these standards can trigger environmental downgrading. RPN farmers, because of their entrepreneurial capacity and smoother process of re-environmentalizing into regional networks, compared to farmers in GPNs, are able to internalize knowledge and environmentally upgrade more sustainably. Finally, LPN farmers perform the least environmental upgrades, due to minimal support from other network actors. Overall, I establish that it is critical to incorporate environmental dimensions in production network and value chain analysis.