Is lightning, a natural phenomenon as old as the Earth, changing under the effect of global warming? This is the question that scientists, HSE managers and critical infrastructure managers around the world are asking more and more often.
Consequently, several studies published in leading scientific journals (Science, Nature Climate Change, Journal of Geophysical Research) have attempted to quantify the link between rising global temperatures and changes in thunderstorm activity. The results are concerning—and have significant implications for lightning protection systems.
What science tells us about the link between lightning and climate
A well-established thermodynamic relationship
The relationship between temperature and lightning is not new. Indeed, thunderstorms form when warm, humid air rises rapidly in the atmosphere, creating convective currents that generate the electrical charges that cause lightning.
However, climate change has a direct effect on these mechanisms: a warmer atmosphere retains more water vapor, thus providing more energy to convective systems. Consequently, conditions favorable to thunderstorms—and therefore lightning—tend to increase.
Key studies: a 12% increase per degree
A landmark study published in the journal Science (Romps et al., 2014) modeled the evolution of lightning strike frequency in relation to global warming. Its findings suggest an increase of approximately 12% in the number of lightning strikes per degree Celsius of warming.
Applied to the most likely IPCC scenarios (+2°C to +4°C by 2100 according to the IPCC AR6 report), this figure implies a potential increase of 24% to 48% in the frequency of lightning strikes worldwide. This is why these results have generated considerable interest in the scientific community and among security professionals.
IPCC AR6: A shift in the global storm regime
The IPCC's Sixth Assessment Report (AR6, 2021) confirms that extreme weather events—including convective thunderstorms—are expected to become more frequent and intense in many regions of the globe. Furthermore, tropical and subtropical areas (sub-Saharan Africa, South America, Southeast Asia)—already among the most exposed to lightning—could see their lightning density increase significantly.
Converging regional studies
Furthermore, regional studies confirm this trend at the local level:
- In Europe, studies published in the Journal of Geophysical Research show an intensification of storm cells in the Mediterranean and central Europe
- In Africa, one of the continents most exposed to lightning, models predict a geographical redistribution of storm activity with areas of marked increase
- In North America, NOAA (National Oceanic and Atmospheric Administration) data indicates a migration of storm zones towards higher latitudes
Lightning and global warming: the mechanisms at play
Convective energy: the fuel of thunderstorms
To understand why lightning might increase, you need to grasp the basic physics. Lightning occurs when two areas of opposite electrical charge — one in the cloud, the other on the ground or in another part of the cloud — reach a potential difference sufficient to trigger a discharge.
This charge separation is produced by intense convective currents within the cumulonimbus cloud. Therefore, the stronger these currents, the greater the lightning production. The strength of convective currents is directly related to the amount of energy available in the atmosphere—which increases with temperature.
Humidity: a multiplying factor
Furthermore, warming increases evaporation from ocean and land surfaces, loading the atmosphere with more water vapor. As a result, future thunderstorms could be not only more frequent, but also more intense—with heavier rainfall and more energetic lightning.
However, researchers point out that the effects of climate change on lightning are not uniform: some regions could see a decrease in thunderstorm activity, while others will experience significant increases. The geographical distribution of this risk is still being studied.
Cloud altitude and the geography of impacts
Furthermore, changes in the vertical structure of the atmosphere influence the height of storm clouds and the trajectory of lightning leaders. This is why the latest climate models seek to incorporate these parameters to refine lightning density projections for the period 2050-2100.
What are the implications for lightning protection?
Facilities designed for current risk, not future risk
Most lightning protection systems currently in service were sized based on ground lightning density data Ng available at the time of their installation — data that reflect past statistics.
However, if the frequency and intensity of lightning strikes increase, some installations designed based on moderate risk assumptions could prove undersized in a context of heightened risk. Consequently, lightning risk studies according to IEC 62305-2 will increasingly need to incorporate climate projections to anticipate future needs.
The need for enhanced monitoring
Furthermore, a higher frequency of lightning strikes accelerates the aging of components in a lightning protection system: wear on grounding electrodes, mechanical fatigue of down conductors, and stress on surge arresters. Consequently, more frequent periodic inspections (VGP) may become necessary at the most exposed sites.
Industrial sites in tropical zones: increased vigilance
In practical terms, industrial sites in sub-Saharan Africa, South America, and Southeast Asia—where lightning strike density is already high—are on the front line. For these critical installations (ATEX sites, data centers, telecom towers, renewable energy sites), the increased lightning risk necessitates a proactive approach.
Tools to anticipate and manage the increased risk of lightning
The IEC 62305-2 risk assessment: an essential prerequisite
Given the evolving nature of lightning risk, a risk assessment according to IEC 62305-2 is more crucial than ever for any protection decision. It quantifies the actual risk to a given installation by incorporating the local lightning density (Ng) and the specific characteristics of the site. This allows for the precise sizing of protection measures—neither insufficient nor oversized.
Physical protection systems: lightning rods and surge arresters
The technical solution begins with lightning protection that complies with IEC 62305 standards:
- ESE (Early Streamer Emission) lightning rod for the protection of structures
- Surge protectors on electrical and communication installations
- grounding system for efficient dissipation of lightning current
In addition, in a context of increasing risk, real-time monitoring via lightning warning systems (Sky Sentinel) makes it possible to trigger HSE procedures before the arrival of a storm.
LPS Manager: Managing lightning risk over the long term
Finally, given the evolving nature of lightning risk, document management and monitoring of installations become strategic imperatives. LPS Manager centralizes all lightning protection records, schedules periodic inspections, and provides access to up-to-date lightning protection data via Strike Radar—an essential tool for maintaining long-term compliance with IEC 62305, regardless of how the risk changes.
Conclusion
In summary, science is establishing an increasingly strong link between climate change and the increased frequency of lightning strikes. With a potential increase of 12% per degree Celsius of warming, industrial infrastructure, power grids, telecommunications sites, and critical buildings will need to incorporate this factor into their protection strategies.
This is why the IEC 62305 standard and good practices for periodic verification are not merely formal obligations: they form the basis of a resilient lightning risk management adapted to the climate challenges of tomorrow.
For any questions about lightning protection for your installations, contact the LPS France — lightning protection experts since 1994, present in Europe, Africa and internationally.
