The 'moss wall' that helps cities breathe

Because of a collaborative effort between a high school cross country team and Chispa, an environmental advocacy group, Arizona’s Phoenix Union High School District has bought its first electric school bus. While nearly three times more expensive than a regular school bus, the school district considered the long-term sustainability, not just in terms of fuel and maintenance costs, but in regards to larger, environmental efforts as well.

In Brazil, the world's largest producer of sugar cane, industry leaders have found a way to harvest the crop without sugar cane burning. Sugar cane burning is harmful to the environment and nearby residents. After complaints and regulations, producers invested in technology that allows them to cut the cane without burning it. This is a contrast to South Florida, despite producing less sugar cane than Brazil, producers in the state continue the practice.

CityTree doesn't resemble the typical tree, but it provides the environmental benefit of 275: this structure, designed for urban landscaping by "Green City Solutions," filters air, cools the surrounding environment and removes CO2 and harmful air pollutants. As climate change worsens our air quality, these structures have proven to monitor and combat the air pollutants in cities all over the world.

Researchers in Australia have discovered a way to capture CO2 from the air and turn it back into solid carbon. The new method uses liquid metal and electricity to process the CO2 and store it at room temperature – something that until now had not been possible. Scientists say it shows potential for large scale use – in combination with sustainable energy – as the world continues to grapple with the effects of climate change.

Respiratory diseases caused by air pollution now account for more premature deaths in people worldwide than malaria and HIV combined. To address increasing contamination levels, particularly in cities, scientists have developed a new kind of cement that absorbs pollutants like CO2. The special cement is being manufactured in Milan, and used around in the world in cities like Paris and Chicago.

An economic shift to renewable energy could take decades, but thanks to rapidly evolving disruptive technologies, dropping prices of solar and wind power sources, and increasing market demand for green business, the new age of renewable energy could encompass the world economy much more quickly.

Twenty-first century cities face the factors of climate change with intensity as urban heating threatens human and the earth’s health. The University of Notre Dame has conducted research on green and cool roofing projects in the city of Chicago. They have found that green and cool roofs help mitigate the heat in cities; however, these roofs should be installed with other strategies like ponds and trees.

Caltrain's $2.4 billion electrification of 51 miles of track replaced diesel trains with faster electric ones, resulting in ridership increases (it doubled on weekends) and shorter trips. This also led to an 89% reduction in riders' exposure to toxic pollution and an estimated 250,000 metric tons of annual carbon emissions reductions.

Kigali's Car-Free Sundays encourage exercise and offer health screenings, with nearly 50,000 residents screened for non-communicable diseases, like high blood pressure, during these events between 2016 and 2020. The events aim to not only encourage healthier lifestyles, but also to promote cleaner air by reducing the number of cars on the road.

In Cambodia 2.5 million people use stoves fueled by forest biomass; charcoal and wood. The emissions caused by using biomass are extremely harmful not only to people but also to the environment. The emissions caused by biomass globally are equal to those of the aviation industry. To counter the problem, several organizations and companies are providing alternatives for Cambodian families like electric stoves. One company, Khmer Green Charcoal, created stoves that run on “clean” charcoal made from coconut shells. More than 6,500 households across the country have made the transition.