The 13th Symposium on ICT, Environment and Climate Change was convened on 13 May 2019 in Geneva, Switzerland under the theme: "the role of frontier technologies in combating climate change and achieving a circular economy." It tackled the transformative potential of frontier technologies in combating climate change, achieving a circular economy, and consequently uphold the achievement of the sustainable development goals (SDGs). Yet, frontier technologies present several challenges particularly regarding those who do not have access to the information and communication technology and hence could be left behind. Social and economic inequalities could also be seen among marginalized groups and women. Frontier technologies are generating emissions due to the lack of policies required to improve effective climate and circular actions in developing and developing actions. To this aim, the symposium recommended the following actions: a) promote the use of AI and other frontier technologies to accelerate climate and circular economy actions, b) establish a comprehensive framework to ensure positive technological disruption, c) encourage multi-stakeholder partnerships and international cooperation to facilitate sustainable and inclusive growth, d) implement international standards to harmonize the deployment of next-generation ICT infrastructure and evaluate the environmental impacts of frontier technologies, e) raise awareness on the role of frontier technologies in combating climate change and achieving a circular economy, f) reduce the negative impact of ICT-related e-waste to contribute to tackling climate change and moving to a circular economy, and g) direct frontier technologies to reduce societal greenhouse gas emissions in line with scientific trajectories and to foster a circular economy.