Short answers, pulled from the story.
In the year 2007, humanity crossed a quiet but monumental threshold for the first time in history where more than half of the global population began living in cities. This event marked the culmination of a slow, centuries-long transformation that began when the first hunter-gatherers gathered into villages thousands of years ago.
The true engine of modern urbanization ignited in the late 18th century with the British Agricultural and Industrial Revolutions. These revolutions shattered a millennia-old equilibrium where rural and urban populations remained in a fixed balance and freed laborers from the land to converge on booming industrial cities.
In Doha, Qatar, land-surface temperatures increased annually by 0.65 degrees Celsius between 2002 and 2013. This trend threatens to make urban living increasingly hostile to human health due to the creation of urban heat islands where industrial areas absorb and retain heat.
In the United States, nearly 23.5 million people live in food deserts lacking access to supermarkets within a mile of their homes. This lack of access correlates with higher rates of obesity and other health disparities among the population.
As the world moves toward a future where nearly 70% of the population will live in cities by 2050, the challenge is no longer just about building more housing. The United Nations has identified Sustainable Development Goal 11 as a central pillar of global policy to make cities and human settlements inclusive, safe, resilient, and sustainable.