More and more people are concentrating in major urban centers. While cities are full of people and possibilities, this is far from making them welcoming environments. Loneliness and anxiety are common in the fast-paced life of the "concrete jungle," and nature may hold the key to alleviating these feelings.

Numerous studies have been published showing how contact with nature positively affects our health. Listening to birds chirping, getting your hands in the dirt, or spending time in contact with greenery—all of this benefits our physical and mental well-being. Now, researchers have shown that green spaces also help alleviate feelings of loneliness.

As the global population increasingly concentrates in urban centers, land in major cities is becoming progressively more expensive. Meanwhile, rising sea levels driven by climate change threaten the housing of millions worldwide—it is estimated that 800 million people will be at risk by 2050.

Living on water could offer a solution to both of these major challenges. This very premise inspired a new neighborhood in Amsterdam, the capital of the Netherlands—a country with a long history of adapting to environmental adversity, where a quarter of the land lies below sea level.

Bringing lighting to those in need using solar energy and affordable materials. This is the mission of the NGO Litro de Luz, which, during a three-day campaign, positively impacted the quality of life of 173 families from riverside communities living along the banks of the Rio Negro in the Amazon.

Rubber from discarded tires can replace 100% of conventional aggregates used in manufacturing concrete. This is what engineers at RMIT University in Melbourne, Australia, have discovered. The concrete made with the material meets building codes and promises to boost the circular economy.

This “greener concrete” uses rubber from discarded tires instead of gravel and crushed stone. According to the team that developed the material, the new concrete is lighter and promises to significantly reduce manufacturing and transportation costs.

A UN survey revealed that in 2018, approximately 55% of the world's population lived in cities. This figure is projected to reach 60% by 2030. If urban centers are to become home to so many, evaluating these spaces and ensuring quality of life is essential – a challenge when considering population density and the impact of such large numbers.

Yet, urban living does not have to mean being cut off from nature, surrounded by gray and concrete. Green cities are proof of this. While life in urban centers poses a series of challenges, it also presents an opportunity to find solutions that transform these spaces, fostering significant and necessary societal change.

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Paradise beaches can quickly lose their appeal for tourists when invaded by sargassum, a brown algae of the genus *Sargassum C. Agardh* distributed across tropical and subtropical oceans. In Mexico's Riviera Maya, this seaweed was once considered a major problem. However, Omar de Jesús Vazquez Sánchez saw it as a raw material for homebuilding—transforming sargassum into sustainable bricks.

Researchers from the Graduate School of Oceanography at the University of Rhode Island have published a study showing that New York City is sinking under the weight of its countless, massive buildings. The skyscraper density of the Big Apple is increasing the risk of flooding in the city.

In addition to flooding and sea level rise driven by climate change, the risk for New Yorkers is growing because the city is sinking by an average of 1 to 2 millimeters per year, with some areas sinking at twice that rate.

Architects Amit and Britta Knobel Gupta moved from London, England, to New Delhi, India, and confronted a severe problem: air pollution unlike anything they had ever seen. To help make the air more breathable and the city more livable, the couple developed a tower designed to purify the air through design. “Our main business is architecture; we didn't want to get into air purification,” Amit said. “But the pollution here was simply unacceptable. It’s very bad.”

And they are right. A study published by the medical journal *The Lancet* revealed that in 2019 alone, air pollution caused nearly 1.6 million deaths in India. New Delhi is regularly shrouded in smog, with vehicle emissions, crop burning, and coal-fired power plants all contributing to the decline in the city's quality of life. It was against this backdrop that the newcomers decided to take action.

Many people are in need of shelter. War, extreme weather events, and famine... Unfortunately, these crises are frequent and lead to large-scale migration. Welcoming individuals in extremely vulnerable situations is a challenge. Ensuring comfort, well-being, and dignity is a humanitarian imperative. Today, there are around 103 million displaced people worldwide, and climate change could significantly increase this number.

London is one of the world's great metropolises and faces a challenge common to urban centers: air pollution caused by fossil fuel vehicles. To combat this issue, the city established Low Emission Zones in 2008, fining large vehicles operating with pollutant emissions above established limits.

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Between October 31 and November 6, 2023, Portugal produced more than enough renewable energy to meet the entire country's demand. While fossil fuel plants were still operational, the clean energy generated was more than sufficient to supply the grid. Consequently, consumer electricity rates dropped drastically.