Climate Change is a Health Emergency Right Now, Warns Leading Intensive Care Expert

Climate change is not a problem for future generations—it is a present-day threat to our health and survival, according to a stark warning from Professor Hugh Montgomery, a leading intensive care physician at University College London. Writing in the British Medical Journal, Montgomery challenges what he describes as comfortable “lies” that we can somehow adapt to climate impacts or that urgent action can wait.

Despite three decades of international climate negotiations, greenhouse gas emissions continue to rise. In 2025 alone, they increased by 1.1 per cent. Meanwhile, the predicted health impacts are now becoming visible. A 2009 assessment from the Lancet Commission identified climate change as “the greatest global health threat of the 21st century”—a warning that has largely gone unheeded.

The cost of climate inaction is already hitting hard in financial terms. The European Union experienced weather and climate-related damage costing €59.4 billion in 2021 and €52.3 billion in 2022. The 2021 Texas winter storm alone caused close to $200 billion in damages and triggered a grid failure affecting millions. Pakistan’s devastating 2022 floods cost approximately $40 billion, whilst Italy’s 2022 heatwave damaged agricultural output by $6.5 billion.

These are not abstract figures. They represent real disruption to food supplies, energy systems, and economic stability—the fundamental building blocks of public health. A 2023 global heatwave may have cost as much as 1.3 per cent of China’s entire gross domestic product. Insurance actuaries have reached a stark conclusion: our economy may not exist at all if climate change is not mitigated.

The delay in action stems from a fundamental misreading of the climate crisis, according to Montgomery. Investors and policymakers have assessed climate impacts using global average surface temperature rather than focusing on extreme weather events. They have failed to account for non-linear acceleration—the possibility of sudden “tipping points” that could trigger cascading collapse, much like removing blocks from a Jenga tower.

On this basis, decision-makers have argued that the short-term costs of climate action outweigh the longer-term damage from inaction. They have assumed that perpetual three per cent economic growth will be largely immune to climate consequences. Reality, Montgomery argues, has already shown these assumptions to be dangerously flawed.

The Carbon Tracker Initiative, drawing on assessment from more than 60 climate experts, warns of sudden, cascading, and interacting disruptions to agriculture, power generation, trade, finance, migration, geopolitics, and human systems. Climate shocks will fundamentally alter where people can live, what can be produced, how infrastructure functions, and which regions remain economically viable.

Alongside disease, starvation, rising sea levels, and economic collapse comes mass migration. The UN Secretary-General warned in 2023 of a potential “mass exodus of entire populations on a biblical scale.” With migration, poverty, and ecosystem collapse comes conflict and geopolitical instability.

Climate change is already recognised by European nations as a “national security threat.” This assessment has been reinforced by the UK’s defence and intelligence community in their 2026 assessment, which explicitly states that “UK national security and prosperity” are under threat from cascading climate-driven risks leading to geopolitical instability, economic insecurity, conflict, migration, and water insecurity.

Despite the urgency, Montgomery emphasises that individual and collective action remains possible. He identifies five key moves anyone can take: switch to renewable energy providers, move personal bank accounts to institutions supporting decarbonisation, change dietary choices, shift transport patterns, and—crucially—talk about these changes with others.

The exponential power of social influence matters. If seven people change their behaviour, and each of those persuades seven more, within twelve cycles of change some 16 billion people would be transformed—twice the global population. This demonstrates that individual agency, multiplied through communication, can drive systemic change.

For people living in Kent, climate change poses specific regional risks, from flooding in low-lying areas to pressure on water supplies and agricultural productivity. Kent and Medway NHS Trust, along with local GP services, are already preparing for increased demand from heat-related illness, water-borne disease, and mental health impacts from environmental anxiety.

Residents can contact their local NHS services for advice on heat resilience, particularly for vulnerable family members. More broadly, Montgomery’s message is one of both urgency and agency: delaying action is not a viable option, but neither is passive acceptance. The science is clear, economists have calculated the cost, and intelligence services have identified the security implications. The question now is whether these converging warnings will finally drive meaningful action at individual, community, and policy levels.

Key Takeaways

• Climate change is already causing measurable damage to human health and economic systems, not merely threatening future generations
• Extreme weather events cost billions annually; the 2023 global heatwave alone may have cost 1.3 per cent of China’s GDP
• The UK’s defence and intelligence community formally recognises climate change as a national security threat to UK prosperity and stability
• Individual action, multiplied through social persuasion, can create exponential behavioural change
• Policymakers have fundamentally underestimated both the pace of climate impacts and the economic costs of inaction

What This Means for Kent Residents

Climate change poses direct health risks to Kent’s population, from heat-related illness during extended heatwaves to flooding in vulnerable areas and emerging water shortages. Residents experiencing health concerns related to extreme weather should contact their GP or call NHS 111 for advice. Local NHS trusts are integrating climate resilience into service planning, but individual preparedness is equally important. Professor Montgomery’s call to action—switching energy suppliers, adjusting diet and transport, and discussing these changes with neighbours—is particularly relevant for communities like Kent, where collective action can build genuine resilience whilst contributing to national emissions reduction targets.