Increased urbanisation has led to a worsening in the quality of life for people in large cities due to the increase in indoor temperatures. Retrofitted green roofs may attenuate housing temperatures, due to the isolation and passive cooling properties of these vegetated systems. For this purpose, this research reports on an experiment using a green roof modular system to compare indoor and outdoor temperatures before, and after, a green roof set up in an existing depot in Rio de Janeiro, Brazil characterized by high temperatures for most parts of the year. The modular system comprised previously used pallets covered with geotextile and planted with succulent species with low watering needs and reduced maintenance processes. Compared to the outdoor environment, mostly warmer indoor conditions were converted to cooler temperatures and due to its thermal properties, which provide insulation, evapotranspiration, and shading the green roof system presented a potential to attenuate the heat exchange and improve indoor conditions. A homemade lightweight modular system can widespread green roofs on a city scale.

Within the context of climate change and other environmental stressors, water scarcity has become a major concern in urban areas of the Sahel region of Africa. Water is an important resource and its scarcity which is exacerbated by socio-economic inequalities has created unequal power relations and conflicts. From this guiding premise, this work seeks to examine challenges in ensuring effective drinking water supply and how they have reshaped relations in urban areas using the case of Doba. A mixed methods approach was employed and includes documentary research, a questionnaire survey with 120 purposively selected households, 11 in-depth interviews and a collection of water samples for quality analysis. Data collected was analyzed qualitatively and quantitatively while water quality analyses were conducted at the Sarh laboratory. Under the lens of the Urban Political Ecology (UPE) approach, results revealed that households drink water from boreholes (31%), open wells (48%), springs (8%) and pipe born water (20%). The physicochemical analysis showed an iron level of 0.24 mg/L in tap water and the turbidity rate of 48.20 Nephelometric Turbidity Units (NTU) in well water while bacteriological analysis gives a total aerobic chlorine level of 100 CFU/100 ml in all the waters sources analyzed. These inequalities results from poor state of infrastructure, climate change and socio-economic differences at the level of households. This has resulted to conflicts between the state water supplying institutions and dwellers and between dwellers themselves over water sources. This work has a policy implication as the provision of drinking water requires concerted efforts between all stakeholders.

To investigate the impact of prolonged exposure to enclosed, low-light environments on carbon fixation and oxygen release in green plants, as well as their capacity to regulate transpiration and humidification, this study utilized Ficus pandurata Hance, a common indoor ornamental plant, as the experimental subject to examine the net photosynthetic rate (P_n) and transpiration rate (T_r). LI-6800 portable photosynthesizer was employed to assess the P_n and T_r of Ficus pandurata Hance cultivated under varying temperatures (15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃) and different CO₂ concentrations (400 µmol·mol⁻¹, 800 µmol·mol⁻¹, 1200 µmol·mol⁻¹) at different parts of the room (indoors or near windows). The results of the light response curve and the CO₂ response curve measurements indicate that the P_n of Ficus pandurata Hance shows a trend of initially increasing and then decreasing as the light intensity or CO₂ concentration increases. It is noteworthy that under different photosynthetically active radiation (PAR) and CO₂ concentrations, the maximum P_n of Ficus pandurata Hance cultivated by a window is significantly higher than that of indoor-cultivated plants. Under appropriate temperature control (20~30 ℃), the P_n and T_r of Ficus pandurata Hance are highest at 800 µmol·mol⁻¹ CO₂ concentration. Under appropriate ventilation conditions (CO₂ concentration < 1200 µmol·mol⁻¹), the plants have stronger carbon fixation ability under appropriate temperature conditions and stronger transpiration—induced humidification ability under non-low temperature (T ≥ 20 ℃) conditions. To sum up, in the case of high CO₂ concentration caused by poor indoor ventilation and dense population, cultivation of Ficus pandurata Hance by the window and proper control of temperature above 20 ℃ can obtain good ecological benefits of carbon fixation, oxygen release, transpiration and humidification.