June 2026 was the hottest June recorded for western Europe and the second warmest globally, driven by the highest sea surface temperatures (SSTs) on record.
- Separately, a study has highlighted that Heatwaves resulted in declining photosynthesis in nearly 57 million hectares of tropical forests, reducing growth and increasing risk of plant mortality.
- Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
About Heatwaves
- A heatwave is a weather phenomenon defined by the ‘local cumulative excess heat over a sequence of unusually hot days and nights.’
- The World Meteorological Organization defines a heat wave as five or more consecutive days during which the daily maximum temperature exceeds the average maximum temperature by five degrees Celsius.
Factors Causing Heatwaves
- High-Pressure Systems: Trap hot air, creating a heat dome and preventing heat from escaping.
- Clear Skies: Reduced cloud cover allows greater solar radiation, increasing surface temperatures.
- Climate Change: Rising global temperatures increase the frequency, intensity, and duration of heatwaves.
- Urbanisation: Dense infrastructure and limited green spaces reduce natural cooling and create urban heat island effect.
- Land-Use Changes: Deforestation and agricultural expansion alter the surface energy balance and local climate.
