We evaluated the effects of the global lockdown on society and the environment. We found drastic changes in government policies in response to COVID-19, such as increasing expenditures, reducing human movement, reducing human mobility/working style, and consequently reducing air pollution, as evidenced by NO2 data. The reduction in air pollution may result from the reduction in economic and transportation activities [9, 19–21]. For example, the absence of motor vehicle traffic and suspended manufacturing during the COVID-19 pandemic in China led to a ~ 90% reduction in NO2 emissions countrywide [22]. The global economy drastically slowed due to the COVID-19 pandemic [23]. As the changes in NO2 emissions are consistent with those in other emissions such as carbon dioxide (CO2), ozone (O3), and fine particulate matter (PM2.5) [20, 24, 25], the NO2 emission level can be regarded as an air pollution indicator. Thus, we found the degree of reduction in air pollution response to the lockdown as a proxy through the NO2 observation. Most countries in the world reduced air pollution through their lockdown policies (Fig. 2b).
These changes began in early March 2020 after COVID-19 spread globally. Such global changes in society due to a global lockdown have not been observed previously due to limited observation techniques. In this study, we examined the global lockdown consequences for human movement and ecosystems using current technologies, such as human location big data via the Global Positioning System and satellite images. Global consequences of the lockdown have been observed for other phenomena, such as CO2 emissions [9], air PM2.5 concentration [26], human mobility via ‘Disease Prevention Maps’ by Facebook users [27], and environmental noise [28]. We have provided new consequences of the global lockdown, with results similar to those of previous reports.
The COVID-19-induced lockdown may negatively affect the achievement of the SDGs concerning food, the economy, and infrastructure (e.g. Goals 3 and 9). The lockdown is expected to substantially influence the food supply chain [29], infrastructure, and the economy [23] due to restricted human movement, food production, and economic activities. The global lockdown may accelerate the achievements of certain SDGs, especially those focused on improving human health and conserving ecosystems. Especially for food security, some studies have assessed the impact of the COVID-19 pandemic on food security and resulting health effects [30–32]. Galanakis [33] surmised that the COVID-19 pandemic had created a new era for food-supply chains. We will have to face many significant challenges, e.g., ensuring food safety and security, reducing losses and food wastage, as well as identifying alternative, safe protein sources that meet the nutritional expectations of consumers.
The global lockdown may reduce global climate change due to the relative decline in air pollution (Goal 13) [9, 26], conserve sustainable cities [11], and protect life on land [15] through a lower human impact on ecosystems [5]. Consequently, human health may improve, excluding those who contract COVID-19 (Table S1). These improvements are primarily due to restricted human movements and economic activities, which reduce air pollution. Certain scholars expected reduced human mobility and activity during the global lockdown to significantly impact ecosystems because reducing the human impact on the environment allows ecosystems to recover and conserves species [4, 34].
Regarding persistent effects on SDG achievements up to 2030, the SDG scores changed drastically from the immediate ones. The achievements of climate change and ecosystem protection, such as Goals 11, 13, and 15, predominantly shifted from positive to negative, while those of economic issues, such as Goals 9, 10, and 16, primarily exhibited a negative to positive trend. This occurred primarily because economic recovery that goes against ecosystem protection can be expected to occur after the global lockdown. Forster et al. [35] simulated the increase in global temperature after the economic recovery up to 2030. Therefore, global economic recovery could substantially affect the persistent achievements of the SDGs concerning ecosystem protection and climate change mitigation. Furthermore, there were conflicting effects among goals protecting biodiversity and those promoting economic development [16, 36]. Therefore, a comprehensive debate is necessary to consider the achievements of SDGs concerning economic recovery and ecosystem management after global lockdown.
There is a growing body of scientific information on how to achieve SDGs 16, 37–39], and the impacts of the global lockdown have been well evaluated using the current global policy framework. Moreover, major global lockdown policies and the subsequent economic recovery, such as the cohesion policy of developed countries, may not consider the future SDG achievements for 2030. Therefore, policies concerning SDGs should be considered while factoring in the global lockdown and subsequent economic recovery.
This study and perspective has certain limitations. Our simple score analysis for SDG achievements represents findings in the literature on how the global lockdown affects the SDGs. Although we carefully considered the scores, certain scores may have been overlooked or underestimated. In addition, we should assume that new evidence of the global lockdown effects on SDGs will be published in the future. Considering these limitations, the scoring estimates have various uncertainties. Therefore, we recommend studying the reality of SDG achievement in the future by directly measuring the SDGs, human movement, and air pollution. We scored the SDG achievement at the global scale by limiting the data; however, developing countries are more severely influenced by the global lockdown due to their limited governmental budgets [40]. Therefore, we encourage the assessment of SDG achievements at the country or regional level.
Recently, with increasing levels of COVID-19 vaccination, the lockdown has been reduced in parts of the world. The changing lockdown situation could improve or reduce the SDG achievements at the country scale as well as the global scale. Moreover, use of resources for the COVID-19 pandemic, e.g., lockdown, is likely to hinder reactions to concurrent threats (e.g., heat waves, wildfires, drought, and extreme weather) as under-resourced systems and emergency responses become stretched and disrupted [41], radically transforming the current state of global development [42]. Such threats increase the potential for geopolitical unrest, and the cost of dealing with these stressors could divert funding from the existing SDG targets [6].
In conclusion, we have highlighted changes in society, the environment, and SDG achievements due to the immediate and persistent effects of the global lockdown caused by the COVID-19 pandemic. Global lockdown significantly impacted society and the environment. Moreover, it greatly impacted the immediate achievements of most SDGs, with mainly negative and positive effects on economic and environmental issues, respectively. In addition, we found there were persistent effects on achievements for most of the goals. We are at a critical turning point for the future of human society and the Earth, and the SDG achievement analysis provides powerful evidence for this from the SDG perspective [39]. In addition, the SDGs represent a leap forward compared to the Millennium Development Goals [43]. Humanity is currently facing the COVID-19 pandemic; however, to achieve a sustainable society shared principles and legislation among nations must be developed. The political choices made during and after the COVID-19 pandemic could potentially assist the development of a sustainable society by 2030.