## 1 Introduction  
Minimally invasive surgery (MIS) has led to significant advancements in the field of abdominal, thoracic, orthopedic, and head and neck surgery over the past three decades, with numerous advantages over the open approach, such as faster recovery, shorter hospital stays, less postoperative pain, and more aesthetic results [1, 2, 3, 4, 5]. Reports show that the number of MIS procedures has dramatically increased in the past 20 years. In 2020, it was reported that 14 million laparoscopic procedures were performed worldwide, which is associated with an estimated global expenditure of 13.7 billion USD/year on laparoscopic instruments and devices [6]. Moreover, owing to recent advances in robot-assisted surgery, the number of robot-assisted procedures is exponentially increasing due to several factors, such as a shorter learning curve [7]. MIS has been embraced in urology (radical prostatectomy, partial nephrectomy (PN) and radical nephrectomy (RN), radical cystectomy (RC) with continent or non-continent urinary derivations [8, 9]), general surgery (cholecystectomy, appendicectomy, bariatric surgery,lectomy, etc.) [10, 11, 12], and gynecology [13]. In the past, surgeons were more likely to use disposable laparoscopic instruments to establish sterility or to avoid failure of reusable tools. However, expenditures on disposable laparoscopic instruments are generally higher than those on reusable instruments, considering decontamination, repair, and replacement costs. In 2019, more than 4% of worldwide net greenhouse gas (GHG) emissions depended on the healthcare sector [14]. In contrast, the utilization of disposable instruments represents the major hotspots for CO\({}_{2}\) emissions within operating rooms (ORs) [15]. The most common measure used to calculate environmental damage is carbon footprint (CF), and GHG emissions associated with a product, process, or system are equated and summed as CO\({}_{2}\) equivalents. Several studies have proven that reusable instruments in the OR setting have less environmental impact than their single-use counterparts, including instruments such as scissors, gowns and drapes, laparotomy pads, sharp containers, and a vast array of anesthetic items, such as anesthetic drug trays, laryngeal masks, airways, laryngoscope handles, and blades [16, 17, 18, 19, 20, 21, 22]. Hybrid instruments, also called \"reposable instruments\" or \"modular systems\", are mainly reusable but have some disposable components. As a result, these devices are likely to reduce the environmental impact and cost of single-use laparoscopic instruments. However, despite evidence supporting the environmental benefits of reusable instruments, many centers, including those in this study, rely on single-use tools due to sterility protocols, maintenance concerns, and administrative procurement preference. In this context, we hypothesize that robot-assisted nephrectomy has a lower CF than laparoscopic nephrectomy, primarily due to reduced reliance on single-use instruments and shorter hospital stays. This study aims to assess the environmental impact of minimally invasive surgery by comparing the CO\({}_{2}\) emissions of laparoscopic and robot-assisted procedures. Using the GHG protocol and life cycle assessment (LCA) methodology, we evaluate the CF associated with surgical instruments and overall energy consumption for both RN and PN performed in two tertiary referral centers.