New research released on June 12, 2022, adds substantial weight to the scientific case that climate change is producing stronger, more destructive storms around the world, with specific attribution of observed trends to warmer oceans, a moister atmosphere, and shifts in large-scale atmospheric circulation that together amplify the intensity of a wide range of extreme weather events. The findings, published as a synthesis drawing on peer-reviewed research from dozens of laboratories and institutions, have been presented at a coordinated briefing by major climate science bodies and have been described by researchers as the most comprehensive statement yet on the connection between climate change and storm intensity.

The synthesis covers multiple categories of storm: tropical cyclones — variously known as hurricanes, typhoons, or cyclones depending on the ocean basin in which they form; extratropical cyclones at higher latitudes; severe thunderstorms and associated hazards including tornadoes, hail, and damaging winds; and specific storm systems that combine features of multiple categories or that involve specific interactions with other weather phenomena. For each category, the research documents specific trends in observed intensity, examines the physical mechanisms by which climate change is contributing to those trends, and assesses the evidence for future projections.

The Scientific Picture

The findings are striking in their specificity and in their consistency across different research groups and methodologies. For tropical cyclones, the evidence for increasing peak intensity is now described as strong, with specific attribution to rising sea surface temperatures that provide the energy on which the strongest storms depend. The proportion of tropical cyclones reaching the highest intensity categories has been rising in several basins, and rapid intensification events — in which a storm's maximum sustained winds increase by at least 55 kilometres per hour within a 24-hour period — have become more common. The amount of rainfall produced by tropical cyclones has also been increasing, reflecting the capacity of a warmer atmosphere to hold more moisture.

For severe thunderstorms, the picture is more complex but includes specific elements of increasing concern. The environmental conditions conducive to severe thunderstorms — including specific combinations of instability, wind shear, and moisture — are shifting in ways that research suggests will produce more frequent severe storms in many regions. Specific hazards associated with thunderstorms, including extreme rainfall, large hail, and damaging winds, have shown trends that are consistent with the influence of climate change, though the attribution of these trends to specific causes is more nuanced than in the tropical cyclone case.

For extratropical storms at higher latitudes, the research documents specific changes in the characteristics of storm tracks, in the intensity distributions of storms in particular regions, and in the specific features of storms including their rainfall-producing capacity and their ability to produce damaging winds. Connections between climate change and the behaviour of the polar jet stream — which influences storm formation and track in mid-latitude regions — have been a particular focus of research, and specific patterns of atmospheric blocking that can produce prolonged extreme weather events have been linked to conditions associated with climate change.

The cumulative effect of these specific findings is a picture in which climate change is not simply shifting averages but is amplifying extremes. The specific storms that produce the greatest damage — the strongest tropical cyclones, the most intense severe thunderstorms, the extratropical systems that combine high winds with extreme rainfall or with storm surge — are, in aggregate, becoming more severe.

Attribution Science

One of the distinctive contributions of the current body of research is the growing sophistication of attribution science — the specific methodology through which researchers quantify the extent to which individual extreme events are made more likely or more intense by climate change. Attribution science, which was a relatively small field a decade ago, has grown rapidly in both scientific maturity and operational capability, and specific attribution statements about recent major storms have become a standard feature of post-event scientific analysis.

Attribution studies typically work by comparing the probability or intensity of an observed event in the climate as it is with the equivalent probability or intensity in a counterfactual climate without human-caused warming. The specific methodologies involved — which draw on extensive model ensembles, observational datasets, and statistical techniques — have been refined through extensive cross-validation and peer review. The results of attribution studies are increasingly being translated into specific operational products, including rapid attribution analyses that can be issued within days or weeks of major events.

For storms specifically, recent attribution work has found that several major tropical cyclones have been made significantly more intense, wetter, or more likely by climate change. Several severe thunderstorm events have been similarly attributed. Specific extratropical storm events — including major European windstorms and specific North American events — have also been the subject of attribution analyses. The pattern across these studies is consistent with the synthesis being released today: climate change is making the strongest storms stronger, even where its effects on specific events are difficult to isolate from the background of natural variability.

What This Means for Communities

The implications of stronger storms for the communities that experience them are substantial, and the research released today is explicit about what they mean in practical terms. Infrastructure designed to withstand storms of specific intensities becomes relatively less capable as storms of greater intensity become more common. Emergency response arrangements designed on the basis of historical storm behaviour may be inadequate for the storms now being experienced and projected. Specific elements of the built environment — including coastal defences, drainage infrastructure, building codes, and specific critical facilities — require evaluation and, in many cases, upgrading to reflect the changing conditions.

Economic impacts of individual storms have been trending upward, driven by the combination of more intense storms and the growing value of assets exposed to them. Insurance markets have been adjusting to the new reality, with premiums rising in many storm-exposed markets and, in specific cases, insurers withdrawing from areas they consider uninsurable at commercially viable rates. Reinsurance, which spreads catastrophe risk across the global financial system, has been a particular focus of attention, with specific reinsurance cycles and capacity pressures reflecting the accumulating evidence of rising storm losses.

Public health consequences of stronger storms extend beyond the immediate toll of injuries and deaths. Storms disrupt medical services, damage health infrastructure, affect water and sanitation, and produce specific stresses on populations with existing chronic conditions. The mental health consequences of major storm events have been increasingly well documented, with specific elevated rates of anxiety, depression, and post-traumatic stress among affected populations extending well beyond the immediate aftermath. Public health systems in storm-exposed regions face specific pressures that the research suggests are likely to grow.

Adaptation and Its Limits

The research released today addresses the question of adaptation — how societies can reduce the harm caused by stronger storms — with a combination of practical recommendations and frank acknowledgement of limits. Specific adaptation measures with strong evidence of effectiveness include updated building codes, improved early warning systems, investments in flood protection and drainage infrastructure, specific land-use planning measures, strengthening of emergency management arrangements, and the development of specific financing instruments for post-disaster recovery.

At the same time, the research is explicit that adaptation has limits. Some impacts of stronger storms — including specific losses of life in events that exceed the capacity of any reasonable warning and evacuation system, certain categories of damage to heritage and ecosystems that cannot be replaced, and specific impacts on populations whose coping capacity is already exhausted — cannot be fully prevented through adaptation. And the scale of adaptation required to keep pace with the continuing intensification of storms is substantial and will require sustained investment over decades.

The adaptation discussion is also shaped by specific equity considerations. Vulnerable populations — including low-income households, specific minority communities, residents of informal settlements, populations in lower-income countries, and specific marginalised groups — typically face greater exposure to storms, have fewer resources to invest in adaptation, and experience greater difficulty recovering from storm impacts. The research highlights the importance of adaptation approaches that specifically address these inequities rather than reinforcing them.

Mitigation and the Longer Term

The findings released today also bear on the broader question of climate mitigation — the reduction of greenhouse gas emissions that drive climate change. The specific research on storm intensity provides additional concrete evidence of the consequences of continued emissions and additional concrete support for the case that reducing emissions has meaningful benefits for the severity of storms that future generations will experience.

The mitigation dimension is important because the future trajectory of storm intensity depends strongly on the emissions trajectory. Projections for higher-emission scenarios show substantially more severe increases in storm intensity than projections for lower-emission scenarios. The cumulative consequences over coming decades — in lives lost, in economic damage, in ecological impact — differ meaningfully between scenarios, and the research released today provides additional specific detail about the scale of the differences involved.

At the same time, the research is explicit that some increase in storm intensity is already built into the climate system through historical emissions. Even with rapid emission reductions, storms will continue to strengthen for some time, and adaptation will remain necessary regardless of the pace of mitigation. The case for both mitigation and adaptation is therefore strong, and the specific tension sometimes posed between them is, from the scientific perspective, largely a false choice.

Political and Policy Implications

The political and policy implications of the research are substantial. National adaptation plans in many countries have been developed with assumptions about storm intensity that may need revision in light of the updated evidence. Specific infrastructure investments, both completed and planned, may require re-evaluation. Emergency management arrangements, building codes, insurance regulation, and specific policy frameworks addressing climate risk all need to be considered in light of what the research suggests about future conditions.

International dimensions are also significant. The specific populations most affected by stronger storms are often not the populations whose emissions have contributed most to climate change, producing the specific equity concerns that have been central to international climate negotiations for decades. The research released today adds specific evidence to those discussions and reinforces the case for the international support to the most affected communities that climate finance frameworks have sought to provide.

The specific role of private-sector actors, including the insurance industry, utility companies, major infrastructure operators, and companies whose supply chains are exposed to storm risk, has also been receiving increasing attention. Disclosure frameworks requiring specific climate risk information, regulatory requirements addressing particular aspects of climate risk, and voluntary industry initiatives have all been active areas, and the research released today will inform their continued development.

Public Understanding

Public understanding of the connection between climate change and stronger storms has been evolving. Surveys in many countries show that majorities of the public now recognise that climate change is contributing to extreme weather, and specific events — particularly major storms that are widely reported and that involve significant damage or loss of life — appear to be particularly consequential in shaping public perceptions. The specific challenge for science communication has been to convey the complex relationships between climate change, weather variability, and specific events in ways that are both accurate and accessible.

Researchers involved in the current synthesis have been explicit that scientific communication around extreme weather remains an area of active work. The specific temptation to attribute any dramatic storm to climate change — a pattern sometimes described as "overattribution" — can undermine scientific credibility and confuse public understanding. At the same time, underclaiming — treating climate change as irrelevant to specific events where attribution evidence supports its role — can also undermine the public policy case for action. Navigating between these risks requires sustained attention to how research is communicated, and to the specific partnerships between scientists, journalists, and communicators that translate research into public understanding.

Looking Ahead

The findings released today will be added to the growing body of evidence on climate change and extreme weather that informs both scientific understanding and practical response. Additional research is continuing across many fronts, including work on specific types of storms and regions, on the interaction between climate change and other drivers of extreme weather, on specific aspects of attribution methodology, and on projections under different emission scenarios. The science is becoming increasingly sharp, and the implications for policy and practice are becoming correspondingly clearer.

The specific actions that follow from the research — in terms of adaptation investment, emissions reduction, and the continued integration of climate considerations into decision-making across multiple sectors — will be shaped by political, economic, and social processes that extend well beyond the scientific community. But the scientific foundation on which those processes rest is now stronger and more specific than it has been, and the research released today contributes meaningfully to that foundation.

For communities that have experienced major storms in recent years, the findings give specific scientific context to events that have shaped their lives. For communities that have not yet experienced such storms but that may face them in the future, the research is both a warning and a guide to the preparations that would be prudent. For policymakers, it is a further call to the action that the cumulative evidence increasingly demands.

The relationship between climate change and storm intensity has been clear in broad outline for some time. What today's research adds is a specific and detailed picture that makes the outline sharper and the implications clearer. Whether that sharper picture produces a more decisive response remains to be seen, but the scientific case is as clear as it has ever been.