This chapter explores the interconnections between transnational organized crime (TOC), environmental crimes, and climate change. Grounded in an extensive literature review of scientific and open-source information, this chapter develops a qualitative analysis supported by quantitative data on the uniqueness of transnational environmental crimes (TECs) compared to conventional cross-border illicit markets. TEC enable transnational criminal organizations (TCOs) and other (non-)state actors to obtain substantial profits through the pillaging and destruction of the Earth’s flora and fauna, threatening our planet’s ecosystems and endangering the survival of various states and (non-)human communities. Firstly, it presents an overview of the criminogenic effects of climate change. Secondly, it focuses on the major categories of environmental crimes and TECs. Thirdly, it explores the networked dynamics of the illicit environmental supply chains shaping global patterns of illicit environmental flows between the Global North and Global South. Finally, it underscores the damaging and often permanent effects of TECs locally and globally. By exploring this under-researched form of criminality that generates billions of dollars annually at the cost of the survival of various states, (non-)human communities, and, indeed, the planet itself, this chapter contributes to elucidating and curbing often unconventional threats posed by TOC.