Climate study: Rise in heat deaths will substantially outweigh fewer cold deaths
London School of Hygiene & Tropical Medicine
Climate change will likely result in a significant rise in deaths from heat across Europe, substantially surpassing any decrease in cold-related deaths. This trend persists across climate change scenarios and even under high adaptation to heat, reinforcing the need for aggressive mitigation policies.
A modelling study, led by researchers from the Environment & Health Modelling (EHM) Lab at the London School of Hygiene & Tropical Medicine (LSHTM) and published in Nature Medicine, estimates that changes to the climate could directly result in over 2.3 million additional temperature-related deaths in 854 European cities by 2099 if urgent action is not taken to cut carbon emissions. However, up to 70% of these deaths could be prevented if rapid action is taken.
The study suggests that even if enormous efforts were made to adapt cities to changing temperatures this would not be enough to balance increased health risks due to exposure to heat, especially in the most vulnerable areas such as the Mediterranean region, Central Europe, and the Balkans. Only swift cuts to carbon emissions that keep temperatures down were shown to reduce the number of extreme heat deaths.
Dr Pierre Masselot, lead author at the EHM-Lab at the London School of Hygiene & Tropical Medicine (LSHTM), said: “Our results stress the urgent need to aggressively pursue both climate change mitigation and adaptation to increased heat. This is especially critical in the Mediterranean area where, if nothing is done, consequences could be dire. But, by following a more sustainable pathway, we could avoid millions of deaths before the end of the century.”
According to the modelling study, the ten European cities projected to see the highest temperature-related death tolls by the end of the century are:
Barcelona (Spain) 246,082
Rome (Italy) 147,738
Naples (Italy) 147,248
Madrid (Spain) 129,716
Milan (Italy) 110,131
Athens (Greece) 87,523
Valencia (Spain) 67,519
Marseille (France) 51,306
Bucharest (Romania) 47,468
Genoa (Italy) 36,338
[NOTE: Numbers above represent projected cumulative increase in temperature-related deaths by 2099 due to climate change]
Due to their larger populations the highest numbers of temperature-related deaths are projected in the most populous Mediterranean cities, but many smaller cities in Malta, Spain and Italy are also likely to be badly affected with high temperature-related death rates.
Away from the Mediterranean region, impacts are expected to be less severe, with other European capitals such as Paris (13,515) projected to see a smaller, but still significant, increase in cumulative cold and heat deaths. On the other hand, most cities in the British Isles and Scandinavian countries could see a net decrease in deaths, one being London (-27,455). This lower death toll would however be massively outweighed by the increases in the rest of Europe, resulting in 2.3 million additional deaths across the whole of Europe.
Professor Antonio Gasparrini, senior author of the article and lead of the EHM-Lab at the London School of Hygiene & Tropical Medicine (LSHTM), said: “This study provides compelling evidence that the steep rise in heat-related deaths will far exceed any drop related to cold, resulting in a net increase in mortality across Europe. These results debunk proposed theories of ‘beneficial’ effects of climate change, often proposed in opposition to vital mitigation policies that should be implemented as soon as possible.”
This research uses risk functions of temperature in all cities, accounting for local and age-specific adaptation and acclimatisation. These are combined with projections of temperatures, population, and death rates to estimate expected temperature-related death tolls that can be attributed specifically to changing temperatures. The researchers considered a range of climate and epidemiological simulations to assess the uncertainty associated with the estimates, under scenarios defined for the IPCC sixth assessment report. The researchers additionally computed death tolls for scenarios in which the risk of mortality related to heat is reduced.
Adaptation scenarios devised in this research inform on the degree of risk reduction needed but remain abstract and do not inform on specific action to be taken. Additionally, this research focuses on daily mean temperature and does not account for specific weather events that could modify the estimated death toll such as extreme nighttime temperatures and humidity conditions.
Journal
Nature Medicine
Method of Research
Computational simulation/modeling
Article Title
Estimating future heat-related and cold-related mortality under climate change, demographic and adaptation scenarios in 854 European cities’
Article Publication Date
27-Jan-2025
Trimetallic synergy and defects: a catalyst for climate action
Tata Institute of Fundamental Research
The Discovery
The study introduces a trimetallic catalyst—comprising nickel (Ni), copper (Cu), and zinc (Zn) nanoparticles supported on defective ceria (CeO2)—that achieves unprecedented performance in CO2 reduction. The catalyst demonstrated:
- CO Productivity: An astounding 49,279 mmol g⁻¹ h⁻¹ at 650°C, a nine-fold increase over previously reported catalysts.
- CO Selectivity: Up to 99%.
- Stability: Maintained performance for at least 100 hours without degradation.
The catalyst's extraordinary efficiency is attributed to the creation of a Strong Metal-Support Interaction (SMSI) between the trimetallic sites and the defective ceria. This unique interaction fine-tunes the electronic structure, enabling optimal performance.
Unveiling the Mechanism
This research relied heavily on advanced in-situ techniques and a multidisciplinary collaboration:
- In-Situ HERFD-XANES at ESRF, France
Dr. Pieter Glatzel and the team at the European Synchrotron Radiation Facility (ESRF), Grenoble, played a pivotal role in uncovering the electronic dynamics of the system. High-energy-resolution fluorescence-detection X-ray absorption spectroscopy (HERFD-XAS) revealed how SMSI alters oxidation states and electron density distribution across the catalyst. - In-Situ TEM and EELS at Ernst-Ruska Center, Germany
Dr. Paul Paciok from the Ernst-Ruska Center, Germany, contributed critical insights through in-situ transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). These studies visualized, for the first time, the growth and movement of trimetallic sites under catalytic conditions. Once SMSI was established, the movement ceased, preventing further diffusion or sintering. - Molecular Understanding via DFT at IIT Bombay, India
Prof. Ojus Mohan's group at IIT Bombay utilized density functional theory (DFT) calculations to unravel the reaction mechanism. The studies highlighted how reaction intermediates form and convert into products, driven by a complex interplay of direct dissociation and redox pathways on different active sites.
Why It Matters
The conversion of CO2 to CO is a critical step in transforming carbon dioxide into value-added chemicals and fuels. However, commercial viability has been hindered by low productivity, poor selectivity, and instability of existing catalysts. By leveraging SMSI and defect engineering, this study has overcome these barriers, setting new benchmarks in CO2 reduction catalysis.
This research not only provides a highly effective catalyst for CO2 conversion but also offers a blueprint for designing next-generation catalysts through precise electronic structure tuning and defect manipulation.
Future Implications
These findings open new avenues for the development of advanced catalysts for CO2 utilization and other critical chemical transformations. As Prof. Polshettiwar states, “By combining traditional catalytic materials with cutting-edge defect engineering and SMSI, we’ve shown how to address fundamental limitations in catalysis. The study offers a roadmap for designing advanced catalysts and demonstrates the impact of integrating traditional materials with cutting-edge approaches, offering hope for a sustainable future."
Journal
Proceedings of the National Academy of Sciences
Method of Research
Experimental study
Article Title
Tuning the electronic structure and SMSI by integrating trimetallic sites with defective ceria for the CO2 reduction reaction
