Environment disasters linked to climate change are predicted to cause huge economic loss of 200 billion Euros and endanger millions of people annually and globally by 2040. Internet-of-Things (IoT) and unmanned aerial vehicles (UAVs) are two promising technologies that can monitor environment changes and disasters to save lives and reduce disastrous consequences, but they both have inherent limitations: IoT networks often have high energy consumption and strong dependency on reliable communications, while UAVs cause significant concerns on reliability due to their high mobility and increased network complexity. The INITIATE project brings together an international, multidisciplinary and cross-sector consortium consisting of world-leading academic institutions and specialised industrial enterprises, to create a new generation of intelligent, sustainable and ultra-reliable aerial-terrestrial IoT networks that can equip humanity to fight against environment changes and disasters, through research and innovations (R&I) on advanced technologies in IoT, Artificial Intelligence, UAVs, wireless power transfer, software-defined networking, and network resource optimisation to tackle the associated challenges. INITIATE will boost the R&I capability of partners by performing dedicated research in these multiple disciplines and create a long-term cross-discipline and cross-sector knowledge sharing platform with competent and complementary expertise. The researchers involved will be trained through extensive R&I actions and well-planned networking activities at both Europe and global levels to enrich their skill sets as well as enhance their career perspectives. The INITIATE project will significantly contribute to the European competitiveness and leadership in the key sectors such as ICT, remote sensing, and environment monitoring by creating scientific breakthroughs, boosting R&I capabilities, and training people for improved employability.