Geophysical Phenomena

Introduction:

Climate change has emerged as a critical factor influencing cyclone patterns and frequency globally. Rising global temperatures, warming oceans, and changing atmospheric conditions are contributing to shifts in the intensity, frequency, and geographical distribution of cyclones, posing new challenges for disaster management and coastal communities.

Impact of Climate Change on Cyclone Patterns

1. Increased Sea Surface Temperatures:
   • Cyclones derive their energy from warm ocean waters. As global temperatures rise, sea surface temperatures (SST) increase, providing more heat and moisture to fuel cyclone formation and intensification.
   • Recent Example: In 2023, Cyclone Biparjoy in the Arabian Sea intensified rapidly due to abnormally high SST, demonstrating the impact of warming oceans on cyclone behavior.
2. Higher Frequency of Intense Cyclones:
   • While the overall number of cyclones may not have significantly increased, the proportion of intense cyclones (Category 4 and 5) has risen. Warmer oceans provide more energy, leading to stronger cyclones with higher wind speeds and heavier rainfall.
   • Recent Example: Cyclone Amphan (2020) in the Bay of Bengal rapidly escalated into a super cyclone due to favorable climate conditions, including high SST and low wind shear.
3. Changes in Cyclone Tracks:
   • Climate change is also altering cyclone tracks, with more cyclones forming in unusual regions or deviating from traditional paths. This poses a greater risk to previously unaffected or less-prepared areas.
   • Recent Example: The increasing number of cyclones in the Arabian Sea, such as Cyclone Tauktae (2021), indicates a shift in cyclone activity due to warming waters in the region, which historically witnessed fewer cyclones than the Bay of Bengal.

Impact of Climate Change on Cyclone Frequency

1. Fewer, But More Destructive Cyclones:
   • Some climate models suggest that while the frequency of cyclones may not increase significantly, those that do form will be more destructive due to stronger winds, heavier rainfall, and higher storm surges.
   • Recent Example: Cyclone Fani (2019) was one of the most powerful storms to hit Odisha in decades, and its strength was attributed to the warming of the Bay of Bengal, which fueled its rapid intensification.
2. Longer Cyclone Seasons:
   • Climate change is extending the duration of cyclone seasons, with cyclones forming earlier or later than usual. This increases the window of vulnerability for coastal regions, making disaster management more complex.
   • Recent Example: Cyclone Yaas (2021) hit India towards the end of May, unusually close to the onset of the monsoon season, highlighting the extended cyclone activity period.
3. Rising Sea Levels and Cyclone Intensity:
   • Rising sea levels due to melting polar ice caps and thermal expansion amplify the destructive potential of cyclones by increasing the height of storm surges. This leads to more widespread coastal flooding, even from less intense cyclones.
   • Recent Example: The storm surges during Cyclone Amphan (2020) caused widespread flooding in the Sundarbans, where rising sea levels exacerbated the extent of the damage.

Scientific Consensus and Predictions

1. IPCC Reports on Cyclones:
   • The Intergovernmental Panel on Climate Change (IPCC) in its reports highlights that tropical cyclones are likely to become more intense in the future due to rising global temperatures and changing oceanic conditions.
   • Recent Example: The IPCC’s Sixth Assessment Report (2021) indicates that the frequency of very severe cyclonic storms (VSCS) is projected to increase in the North Indian Ocean, a direct consequence of rising SST.
2. Regional Variations in Cyclone Patterns:
   • Climate change affects different regions in varied ways. The North Indian Ocean is witnessing more frequent and intense cyclones, while other regions may experience fewer storms but with higher intensities.
   • Recent Example: Cyclones like Tauktae and Yaas in 2021 highlight how warming seas in both the Arabian Sea and Bay of Bengal are creating conditions favorable for more destructive storms.

Conclusion:

Climate change is fundamentally altering cyclone patterns and frequency, with cyclones becoming more intense, longer-lasting, and affecting new regions. Governments and communities must adapt to these changing patterns by enhancing early warning systems, resilient infrastructure, and disaster preparedness to mitigate the impacts of these climate-driven events. Continued global efforts to limit global warming are essential to prevent further escalation of cyclonic activity and its associated risks.