Abstract Global crises exhibit common patterns and interlinkages, from which critical lessons can be learned. In particular, the ongoing COVID-19 pandemic offers an unprecedented moment for unearthing insights helpful for climate change response. This research aims to systematically identify, assess, and prioritize such relevant lessons. To this end, we adopted a Horizon Scanning (HS) approach to collect 553 related lessons from multiple sources, including reviewing 108 peer-reviewed journal articles and two surveys. A total of 372 respondents contributed and ranked relevant lessons, of which 31 experts across countries, sectors, and disciplines had ranked the same lessons ranked in the second survey. Adopting the HS approach was not only helpful to collect relevant lessons, but also effective in promoting the general public’s engagement in scientific research, which is essential to amplify its voice regarding two major crises that are directly affecting the lives and livelihoods of people. Results of this research indicate that both participant groups (experts and non-experts) perceived climate change to be more threatening than COVID-19. However, they expressed different areas of concern regarding the two crises. Among all thematic areas, “Research and innovation” and “Policy and governance” are of supreme importance for COVID-19 and climate change. This research provides invaluable information for actors who are at the frontline of fighting both crises.1. IntroductionWith millions of confirmed cases and deaths, the ongoing COVID-19 pandemic is an unprecedented global crisis in the recent history of humanity (Fan et al., 2020). The pandemic has triggered extraordinary social measures (Cole and Dodds, 2021; Hepburn et al., 2020) and heavily affected the global economy (Kumar and Ayedee, 2021) and imposed serious implications for CO2 emissions and the Paris Agreement on climate change (Shan et al., 2021). The implications of COVID-19 on climate change action are enormous, including putting on hold many climate actions (Loureiro and Alló, 2021). For instance, this includes postponing the 26th conference of parties (COP26) in Glasgow (United Kingdom), an important milestone for committing more ambitious Nationally Determined Contributions (NDCs), for one year due to the challenges of holding an inclusive and ambitious gathering of climate change actors. The outbreak of this pandemic seems to be related to several global problems, for instance, climate change, urbanization, and global travel (Barouki et al., 2021). Despite the fundamental differences between the COVID-19 pandemic and climate change (Manzanedo and Manning, 2020), there are interlinkages (e.g. both are global crises), shared patterns (e.g. serious implications on multiple sectors), and commonalities (e.g. multiple root causes and complex interactions) that are typical for the Anthropocene era (Fuentes et al., 2020; Heyd, 2021; Lancet, 2021). Both, COVID-19 and climate change have interferences with development, research, global cooperation, and resilience (Hepburn et al., 2020; Manzanedo and Manning, 2020). To combat the COVID-19 pandemic, global societies have witnessed massive changes in all life aspects, and governments committed to radical measures to control the spread of COVID-19 and reduce losses of lives (Baldwin and Lenton, 2020). On the other hand, the world has been experiencing climate change effects for decades (IPCC, 2021), yet few such drastic measures have been taken, reflecting the urgency of the climate emergency (Coates et al., 2020). This has raised numerous critical questions on comparable global efforts in fighting climate change (Salas et al., 2020), a threatening crisis that moved down the top global agenda because of the pressing urgency to deal with COVID-19 (Lancet, 2021).Delayed action on both climate change and COVID-19 is threatening. Therefore, policymakers and the global community concerned about such global crises must be able to make informed decisions, based on sound scientific findings (Baldwin and Lenton, 2020; Jin, 2020; Manzanedo and Manning, 2020). The current pandemic outbreak offers an exceptional window into a global crisis and provides invaluable insights and profound lessons into how this crisis may be addressed and which policy approaches are considered favorable(8). Reflecting from the COVID-19 pandemic, these lessons can be of political, social, economic, and policy nature, among others. Examples of such lessons that can be found in the literature stress the importance of global solidarity and international cooperation (Cole and Dodds, 2021; Klenert et al., 2020), emphasize how costly a delayed intervention can be (Fan et al., 2020; Fuentes et al., 2020; Heyd, 2021; Jin, 2020), underline the importance of crisis prevention (Cole and Dodds, 2021; Manzanedo and Manning, 2020), highlight how inequality can be exacerbated without timely action (Klenert et al., 2020; Salas et al., 2020), and draw attention to the centrality of research and innovation in facing new challenges (Ching and Kajino, 2020; Jin, 2020). The term lesson used in the current research, thus, refers to the insights that can be drawn from the COVID-19 pandemic and potentially applied to climate change policy making and implementation. Given the wide-spectrum of potential lessons, we are aiming mainly to provide policy-makers at different levels with up-to-date and evidence-based knowledge that can help in making the right decisions regarding climate change, reflecting from the ongoing COVID-19 pandemic.Although several previous studies have contributed to collecting and analyzing such lessons (Andrieu et al., 2021; Baldwin and Lenton, 2020; Botzen et al., 2021; El Zowalaty et al., 2020; Herrero and Thornton, 2020; Hochachka, 2020; Howarth et al., 2020; Kakderi et al., 2021; Manzanedo and Manning, 2020; Negev et al., 2021; Perkins et al., 2021; Prideaux et al., 2020; Ruiu et al., 2020; Salas, 2020; Sarkis et al., 2020; Sheehan and Fox, 2020), no systematic review of these lessons has been conducted. In addition, the number of collected lessons in these studies was limited and, in many cases, confined to limited thematic areas. Employing the Horizon Scanning (HS) approach enables a more comprehensive overview by expanding the information sources across regions, disciplines, and professions, which can be quite helpful to inform and support decision-making (Hines et al., 2019). Enlarging the information sources through the HS has the potential to allow investigating opportunities, threats signs, and outlooks of phenomena. Concerning the aim of the current research, it allows identifying important lessons that might be missed if a single source of information (e.g., literature) is used. As of the date of writing this paper, this is the first research with this scale to collect a magnitude of lessons from COVID-19 that addresses a wide spectrum of thematic areas from published literature, the public, and experts. Therefore, the ultimate goal is to gather, analyze, rank, and reflect on the most critical lessons that, if addressed, would advance climate change action. This research provides recent, useful information for successfully navigating the challenges of climate change reflecting from the ongoing COVID-19 pandemic.