Cities Getting Hotter: The Surprising Truth About Urban Plants

The Problem

More than half the world's population lives in cities, which are getting hotter due to the urban heat island effect.

The Study

Scientists analyzed 761 cities across 105 countries using satellites and weather data.

Key Findings

• In dry places, plants can increase temperatures in about 22% of cities.
• Grass and crops are the main culprits, unlike trees which can cool the air.

Why Does This Happen?

• Plants in dry areas lack sufficient water to cool the air by releasing water vapor.
• Instead, they absorb heat, exacerbating the problem.

Heatwaves Make It Worse

• Trees fail to cool cities in 25% of cases.
• Grass and crops perform even worse:
• Grass fails 71% of the time.
• Crops fail 82% of the time.

The Solution

• Smart planting strategies are needed.
• In dry cities, consider:
• Different types of plants.
• High-albedo surfaces that reflect heat.

Conclusion

• Careful planning is crucial to avoid making things worse.
• Climate-specific solutions are essential for effective urban cooling.