The world production of plastic exceeded 360 million tonnes in 2020 alone, a considerable amount of which is not properly disposed of. The significant pressures and damages posed by conventional plastic to human and environmental health suggest that alternatives are urgently needed. One of them is “bioplastic”, which is defined as bio-based plastic that is (or not) biodegradable. This paper reports on a study on the perceptions of bioplastics among consumers in 42 countries to identify their levels of information and concerns. The results suggest that most respondents have positive expectations regarding the future of bioplastics to replace conventional plastics fully or partially, especially for food containers, kitchenware, and boxes and bags for packaging. They also reported that the low costs and increased availability of bioplastic products on the market are likely to be the main drivers for their wide-scale adoption. However, many participants are unsure whether they would buy bio-based and biodegradable products if they are expensive. Overall, whereas a rather positive attitude to bioplastics has been identified, greater efforts are needed to address the many information needs of consumers towards upscaling the adoption of bioplastics. Relevant policies are therefore needed to encourage investments in the large-scale manufacture and market uptake of bioplastics. The paper reports on an initial study of consumer behavior, in a sample of countries spread across all geographical regions.

The rapid spread of the coronavirus (COVID-19) pandemic affected the economy, trade, transport, health care, social services, and other sectors. To control the rapid dispersion of the virus, most countries imposed national lockdowns and social distancing policies. This led to reduced industrial, commercial, and human activities, followed by lower air pollution emissions, which caused air quality improvement. Air pollution monitoring data from the European Environment Agency (EEA) datasets were used to investigate how lockdown policies affected air quality changes in the period before and during the COVID-19 lockdown, comparing to the same periods in 2018 and 2019, along with an assessment of the Index of Production variation impact to air pollution changes during the pandemic in 2020. Analysis results show that industrial and mobility activities were lower in the period of the lockdown along with the reduced selected pollutant NO₂, PM_2.5, PM₁₀ emissions by approximately 20–40% in 2020.

In recent years, an increasing trend towards replacement of conventional fossil-based plastics with bio-based plastics was noticed, i.e., production of plastics partly or fully made from biomass is rapidly expanding. Currently, bio-based and biodegradable plastics have a very small market size, approximately only 1% of all plastics produced. However, the forecast of the global bioplastics production capacities predicts an increase from approximately 2.417 million tonnes in 2021 to approximately 7.593 million tonnes in 2026, more than three times the current capacity. Therefore, it is necessary to assess the challenges and identify the barriers for bio-based and biodegradable plastics for waste management and to evaluate the effectiveness of current plastic waste management strategies for the efficient waste management of bio-based and biodegradable plastics. The main barriers and motivators of the biodegradable and biodegradable plastics market that have been identified include macroeconomic factors, regulatory factors, technological factors, and social factors. The bio-based and biodegradable plastics have to be separately collected and treated under mostly controlled, regulated conditions. However, currently, there are no legal provisions providing for the separate collection of bio-based plastics, leading to their disposal with either hazardous waste, conventional plastics, or municipal waste. Since the effective plastic waste management strategy relates to good performance in each step of the waste management process, bio-based and biodegradable plastic waste management could, therefore, be based on an effective strategy for the management of plastic waste. However, there is a need for standardizing waste collection systems and creating a harmonized waste collection infrastructure, which would lead to effective sorting of bio-based plastic waste.

The transport sector is one of the largest contributors of CO₂ emissions and other greenhouse gases. In order to achieve the Paris goal of decreasing the global average temperature by 2 °C, urgent and transformative actions in urban mobility are required. As a sub-domain of the smart-city concept, smart-mobility-solutions integration at the municipal level is thought to have environmental, economic and social benefits, e.g., reducing air pollution in cities, providing new markets for alternative mobility and ensuring universal access to public transportation. Therefore, this article aims to analyze the relevance of smart mobility in creating a cleaner environment and provide strategic and practical examples of smart-mobility services in four European cities: Berlin (Germany), Kaunas (Lithuania), Riga (Latvia) and Tartu (Estonia). The paper presents a systematized literature review about the potential of smart-mobility services in reducing the negative environmental impact to urban environments in various cities. The authors highlight broad opportunities from the European Union and municipal documents for smart-mobility initiatives. The theoretical part is supplemented by socioeconomic and environmental descriptions, as well as experience, related to smart-mobility services in the four cities selected.

Nowadays, the increasing rate of human population in urban areas and the importance of urban functions pose a number of ecological cross-boundary challenges. The scientific research of the twentieth and twenty-first centuries revealed dramatic consequences of human intervention into natural ecosystems. The outcome of inadequate consumerism, which promotes industrial growth, and the pursuit of a better life is not only damaging to the natural ecosystems, but will eventually lead the World to dramatic climate change outcomes. Therefore, scientists are looking for ways for sustainable urban transformation without endangering the human population and the environment. According to the identified assumptions, the article investigates the principles of sustainable urban ecosystems. The authors consistently seek to explain the concept of sustainable urban ecosystems in both a broad and narrow sense, focusing on the individual constructs of this term—sustainability, city and ecosystems. The theories and approaches of urbanization and ecosystems are also analyzed in the article in order to highlight the opportunities and specific features of the application. The principles of sustainable urban ecosystems are provided in the modeled system which exposes the interfaces of identified principles and can be used for future studies.

The accurate analysis and comparison of transport indicators from a large variety of urban areas can help to evaluate the performance of different adopted transport policies. This paper attempts to determine important transport and socio-economic indicators from 151 urban areas and 51 countries, based on comparable, directly observable open-source data such as OpenstreetMap (OSM) and the TomTom database. This is the first, systematic indicator-analysis using recent, open source data from different urban areas around the world. The indicator road kilometers per person, sometimes cited as infrastructure accessibility is calculated by processing OSM data. Information on congestion levels have been taken from the TomTom database and socio-economic data from various, publicly accessible databases. Relations between indicators are identified through correlations and regression models are calibrated, quantifying the relation between transport infrastructure and performance indicators. Three sub-categories of cities with different population sizes (small cities, large cities and metropolises) are defined and studied individually. In addition, a qualitative analysis is performed, putting five different indicators into relation. The main results reconfirm previous findings but with a larger sample size and more comparable data. Good correlation values between infrastructure accessibility, socio-economic indicators, and congestion levels are demonstrated. It is shown that cities with higher GDP have generally built more infrastructure which in turn reduces their congestion levels. In particular, for cities with low population density (above approximately 1500 inh. Per sq.km), more roads per inhabitant lead to lower congestion levels; cities with high population density have in general lower congestion levels if the rail infrastructure per person ratio is high. Furthermore, these cities increasing railways per person is more effective in reducing congestions than increasing road length per person.