## 3 UAV Applications in Climate Change Research
### UAVs in Climate Change Research  
The potential of UAVs in climate change research emerged in the early 2000s as miniaturized sensors, GPS navigation, and battery technology enabled lightweight remote sensing platforms. NASA scientists first demonstrated the utility of small fixed-wing UAVs for studying atmospheric dynamics, composition, and thermodynamics in the early 2000s [124]. This pioneering work sparked the recognition that UAVs could fill in the gaps in climate observation networks, given their flexibility, cost-effectiveness, and ability to sample hazardous environments. UAVs were first deployed for humanitarian action in the early 2000s by nonprofit organizations seeking aerial damage assessments after disasters when manned aircraft flights were limited. In 2004, humanitarian groups operated small UAVs to survey post-hurricane flooding outcomes and assess infrastructure damage from the Haitian earthquake [125]. These initial efforts highlighted the potential for UAVs to support disaster relief by providing rapid emergency mapping when access was constrained. The early demonstrations of UAVs for post-disaster mapping and relief accelerated into more operational deployments in the early 2010s. By 2015, UNICEF also tested UAVs in Malawi and the Dominican Republic for transporting medical samples, vaccines, and other cargo as part of the agency's UAV evaluation initiative [126]. This was followed by the launch of the Kazakhstan Drone Corridor as a testing ground for drone delivery systems [127]. These initiatives helped pave the way for more robust and ethical frameworks for using UAVs for humanitarian aid and crisis responses. Figure 9 illustrates UAVs' innovation timeline and integration in humanitarian research since the early 2000s. In climate change research, UAVs are emerging as a valuable tool for monitoring environmental impacts through flexible high-resolution aerial mapping, and have been deployed in multiple climate change research domains, as shown in Figure 10, as exemplified by a case study conducted in the Yukon-Kuskokwim Delta region of Alaska [128]. The researchers implemented multi-sensor-equipped UAVs to autonomously survey and map the challenging terrain, acquiring high-resolution visible, multispectral, and thermal infrared images. The versatility and customizability of the UAV platforms allowed the research team to tailor the systems to the specific scientific requirements of evaluating the landscape changes related to permafrost degradation. Geospatial data analytics generated from the UAV-acquired remote sensing datasets provided the efficient monitoring of the impacts of global warming on critical cultural and ecological heritage sites in the Arctic tundra ecosystem. The study demonstrated the emerging potential of UAV remote sensing to enable rapid, cost-effective, and frequent landscape characterizations, furthering the capabilities for climate change assessment and adaptation strategies. Figure 9: UAV innovation timeline and integration with humanitarian action research. Recent urban expansion coupled with the impacts of climate change have created a need for enhanced methods of monitoring and managing sustainable city developments, as investigated by [PERSON] and [PERSON] [129]. The researchers experimentally implemented UAVs equipped with photogrammetric imaging payloads to autonomously survey and reconstruct 3D digital surface models of building infrastructures at sub-meter resolutions. Compared to the existing means of geospatial data acquisition, UAV mapping demonstrated a greater flexibility, higher cost-efficiency, improved time-effectiveness, and increased safety versus conventional manned aerial mapping. The study results highlighted the emerging potential of UAVs to provide city planning departments with rapid, up-to-date 3D-mapping capabilities to better control urban development amidst the constraints of limited governmental budgets and personnel.