Global Consistency of Wet Bulb Temperature

• Polar regions (NH) and the Alps show the highest increase in WBT.
• Antarctica, though experiencing warming, remains below the snowfall threshold in many areas.
• The Alps lose 3.64% of potential snowfall areas per decade, posing serious consequences for ecosystems and water resources.

These regional discrepancies emphasize the need for localized climate adaptation strategies to mitigate the effects of rising WBT.

2. Comparison with Ground-Based Gauge Data

To ensure accuracy, a reanalysis of WBT data has been compared with ground-based gauge station records from 2011 to 2015. The findings include:

• The ensemble-mean WBT closely aligns with gauge data, achieving a coefficient of determination (R²) of 0.98.
• The error standard deviation is approximately 1.46°C, confirming minimal bias in densely gauged regions.

These validations highlight the reliability of reanalysis datasets in capturing real-world WBT trends.

Comparison with Gauge Data

B/- Consistency Across Reanalysis Products

While reanalysis datasets generally agree on global WBT trends, some discrepancies exist between the Northern and Southern Hemispheres:

• The Northern Hemisphere exhibits a significant and consistent upward trend in WBT across all datasets.
• The Southern Hemisphere shows greater uncertainties, making long-term assessments more challenging.
• The year 2016 recorded the highest mean WBT across all datasets, reinforcing evidence of a warming climate.

The high degree of agreement among reanalysis products supports their credibility in climate monitoring and prediction.

C/- Impact of Wet Bulb Globe Temperature (WBGT) on Human Health

Wet Bulb Globe Temperature (WBGT) is a vital index for evaluating heat stress and human health risks. It is calculated using:

WBGT = 0.7Tnwb + 0.1Tamb + 0.2Tg

Where:

• Tnwb = Natural wet bulb temperature
• Tamb = Dry bulb/ambient temperature
• Tg = Globe temperature

1. Heat Stress and Health Risks

High WBGT levels significantly increase heat-related illnesses such as:

• Heat exhaustion and heatstroke, which can be fatal if untreated.
• Dehydration, impairing the body's ability to regulate temperature.
• Cognitive impairment, reducing mental and physical performance.
• Cardiovascular strain, elevating risks of heart disease.

Vulnerable populations, including outdoor workers, athletes, and elderly individuals, face heightened risks due to prolonged exposure to extreme heat conditions.

Without adequate adaptation strategies, the health impacts of WBGT will continue to escalate in the coming decades.

D/- Health Risks Associated with High WBGT Levels

Analyze thermal comfort and stress during extreme periods

1. Common Health Issues Linked to WBGT

Exposure to high WBGT levels can lead to:

2. Heat-related mortality and Public Health Concerns

• Research suggests that high WBGT levels contribute to excess mortality, especially in urbanized areas with heat island effects.
• Outdoor workers and athletes suffer disproportionately from heat stress-related injuries.

Governments and health organizations are urged to implement heat action plans to safeguard public health.

E/- Preventative Measures to Mitigate WBGT Risks

1. Personal Safety Measures 

• Stay Hydrated: Drink water frequently, even if not thirsty. Avoid alcohol and caffeine.
• Dress Smart: Wear light, breathable clothing and use UV protection.
• Limit Sun Exposure: Avoid outdoor activities during peak heat hours.

2. Environmental and Policy Measures

Improve Urban Planning: Increase green spaces and shade structures.

• Enhance Cooling Facilities: Ensure widespread access to air-conditioned shelters.
• Early Warning Systems: Implement real-time heat stress monitoring.

Proactive steps at both individual and policy levels are essential for reducing WBGT-related health risks.

F/- Conclusion

The global consistency of Wet Bulb Temperature (WBT), validated through reanalysis datasets, highlights significant warming trends, particularly in the Northern Hemisphere. Additionally, the rising Wet Bulb Globe Temperature (WBGT) underscores the growing risks of heat stress and related illnesses due to climate change.

To mitigate these challenges, governments, researchers, and individuals must prioritize:

• Enhanced monitoring and forecasting of WBT and WBGT.
• Stronger public health interventions for heat stress management.
• Climate adaptation policies to reduce heat-related risks.

As climate conditions continue to evolve, a comprehensive understanding of WBT and WBGT will be crucial for protecting both the environment and human well-being.