Limiting warming to 2°C may avoid 80% of heat-related deaths in Middle East and North Africa

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Image: Excerpt of annual total projections of heat-related mortality (per 100,000) risk in 3 countries for the four CMIP6 SSP pathways over the period 2001–2100 from Shakoor Hajat et al, Current and future trends in heat-related mortality in the MENA region: a health impact assessment with bias-adjusted statistically downscaled CMIP6 (SSP-based) data and Bayesian inference. The Lancet Planetary Health, 2023

Date:
April 4, 2023
Source:
London School of Hygiene & Tropical Medicine
Summary:
Over 80% of predicted heat-related deaths in the Middle East and North Africa (MENA) by the end of the century could be prevented if global warming is limited to 2°C, according to a modelling study.

FULL STORY

Over 80% of predicted heat-related deaths in the Middle East and North Africa (MENA) by the end of the century could be prevented if global warming is limited to 2°C, according to a modelling study published in The Lancet Planetary Health.

Under high-emissions scenarios, approximately 123 people per 100,000 in MENA are predicted to die annually from heat-related causes by the end of the century — approximately 60-fold greater than current figures and much higher than predictions under similar scenarios worldwide.

However, if global warming is instead limited to 2°C, over 80% of these deaths could be avoided, highlighting the urgent need for better adaption policies and a switch to renewable technologies.

The findings come as the world prepares for COP28 in Dubai in November.

MENA is one of the most climate-vulnerable regions of the world, with maximum temperatures predicted to rise to almost 50°C by the end of the century, potentially making some areas unliveable.

However, despite this vulnerability, the impact of heat stress in this region, which is worsening due to climate change, remains underexplored.

In the current study, an international team of researchers, including from the London School of Hygiene & Tropical Medicine (LSHTM), modelled current (2001 to 2020) and future (2021 to 2100) trends in heat-related mortality in 19 countries in the MENA region. In their analyses, the team considered variations in the levels of potential greenhouse gas emissions over time and different socioeconomic scenarios.

Under high emissions scenarios (defined by the Intergovernmental Panel on Climate Change Shared Socioeconomic Pathways (SSP) 5-8.5), most of the MENA region will experience substantial levels of warming by the 2060s.

Indeed, under SSP5-8.5, annual heat-related deaths will rise from approximately two per 100,000 currently to 123 per 100,000 by the period between 2081 and 2100. Although current heat-related deaths in MENA are relatively low compared to other regions (two per 100,000 compared to 17 per 100,000 in Western Europe or 10 per 100,000 in Australasia, for example), this rise is expected to be much higher than other regions of the world under similar climate change scenarios. The UK, for example, is expected to see a rise from current figures of three per 100,000 to nine per 100,000 by the 2080s.

Iran is expected to have the highest annual death rate in MENA under SSP5-8.5 (423 per 100,000), with other countries such as Palestine, Iraq and Israel also predicted to have high rates (186, 169 and 163 per 100,000, respectively). Smaller Gulf states, such as Qatar and the United Arab Emirates, will see the greatest relative increases in heat-related deaths.

However, for the MENA region as a whole, if global warming can be limited to 2°C as defined by SSP1-2.6, the team estimate that over 80% of the total 123 annual predicted heat-related deaths per 100,000 people could be avoided.

With COP28 on the horizon, the authors conclude that there is an even greater urgency for stronger mitigation and adaptation policies to be agreed upon, both at the conference and beyond, if MENA is to avoid the worst possible impacts of future warming.

Reliance on traditional heat-adaption solutions such as air-conditioning will not be enough, they warn. Air-conditioning, for example, is used to a relatively high extent in countries where rates of heat-related mortality are higher than the regional average, such as in Israel and Cyprus.

As population growth in MENA will be a substantial driver of predicted heat-related deaths, demographic policies and healthy ageing will also be vital if MENA is to successfully adapt to a changing climate.

Shakoor Hajat, lead author and Professor of Global Environmental Health at LSHTM, said: “Global warming will need to be limited to 2°C to avoid the catastrophic health impacts estimated in our study. Even with stronger action, countries in the region need to develop ways other than air-conditioning to protect their citizens from the dangers of extreme heat.

“Strengthening health systems and better coordination between MENA countries will be key in tackling the health impacts of climate change in the region. With COP28 coming up, discussions are needed to consider how countries in the region can better work together to improve resilience in the face of climate change.”

Story Source:

Materials provided by London School of Hygiene & Tropical Medicine. Note: Content may be edited for style and length.

Journal Reference:

  1. Shakoor Hajat, Yiannis Proestos, Jose-Luis Araya-Lopez, Theo Economou, Jos Lelieveld. Current and future trends in heat-related mortality in the MENA region: a health impact assessment with bias-adjusted statistically downscaled CMIP6 (SSP-based) data and Bayesian inference. The Lancet Planetary Health, 2023; 7 (4): e282 DOI: 10.1016/S2542-5196(23)00045-1

Cite This Page:

London School of Hygiene & Tropical Medicine. “Limiting warming to 2°C may avoid 80% of heat-related deaths in Middle East and North Africa.” ScienceDaily. ScienceDaily, 4 April 2023. <www.sciencedaily.com/releases/2023/04/230404114158.htm>.
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Results Excerpt from Lancet

Projected annual mean anomalies in near-surface temperature and relative humidity averaged over 20-year periods relative to the reference climatological period 1980–2014 are shown in appendix 1 (p 6). The stippling indicates areas where the climate change signal is not significant (ie, the signal is smaller than the inter-annual variability). The selected models and scenarios principally project the same climate change signals with similar temperature trends, indicating the robustness of results. Model agreement about the anomaly sign was at least 70% in all cases.
Under the SSP3-7·0 and SSP5-8·5 scenarios, all or most of the region is projected to experience significant warming by the 2060s, with the greatest warming occurring in North Africa and the Arabian Peninsula. Although some coastal areas around the Arabian Peninsula will undergo an increase in relative humidity, projected changes across the MENA region are non-significant. Corresponding changes in apparent temperature are shown in appendix 1 (p 7). Anomalies are predicted to be larger when the climate variables are restricted to just the summer period of June–August (appendix 1 p 8).

The current annual heat-related mortality risk per 100 000 population, estimated for each MENA country within the four subregions, is shown in appendix 1 (p 9). Egypt has the highest absolute number of heat-related deaths, with a burden of 2591 deaths per year (table). Iran has more than 1700 heat-related deaths per year and is the most vulnerable MENA country per capita, with an estimated 11·0 deaths per 100 000 people per year. Current rates are lowest in Algeria, Morocco, Libya, and the smaller Arab countries in the Persian Gulf. The average annual heat-related death rate across all MENA countries is currently 2·1 per 100 000 people.

TableCurrent annual heat-related deaths, by MENA country
Total annual heat-related deaths Annual heat-related mortality rate per 100 000 people
Algeria 262 0·78
Morocco 250 0·93
Tunisia 116 1·14
Egypt 2591 1·68
Libya 98 0·97
Cyprus 26 3·32
Türkiye 1364 2·40
Syria 575 1·59
Iraq 1091 2·34
Iran 1703 11·00
Israel 218 3·74
Jordan 79 1·13
Kuwait 24 0·84
Lebanon 65 2·15
Oman 17 0·66
Qatar 19 0·95
Saudi Arabia 285 1·03
Palestine 43 1·65
United Arab Emirates 78 0·95
Total MENA countries 8904 2·06
MENA=Middle East and North Africa.

Figure 1 shows the relative change in annual heat-related mortality rates for future periods compared to the baseline period (2001–2020), averaged across the ten climate models. By 2081–2100, we estimate an average 123·4 heat-related deaths per 100 000 people per year across MENA countries under a high emissions scenario (SSP5-8·5). The corresponding rate is 89·8 heat-related deaths per 100 000 people per year under the SSP3-7·0 scenario, 44·9 heat-related deaths per 100 000 people per year under the SSP24·5 scenario, and 20·3 heat-related deaths per 100 000 people per year under the SSP1-2·6 scenario. The Arab countries in the Persian Gulf will have the greatest relative annual increases, with particularly large changes projected for the latter half of the century under the SSP3-7·0 and SSP5-8·5 scenarios. By 2061–80, Saudi Arabia could see a 13-fold increase in heat-related death rates even under a low emissions scenario (SPP1-2·6); however, this could rise to a 63-fold increase under the SSP5-8·5 scenario. A large fraction of the projected rise in MENA countries is driven by population growth: by 2081–2100 the average heat-related death rate across all countries when the population effect is held constant is 78·2 per 100 000 people per year under the SSP5-8·5 scenario, 32·5 per 100 000 people per year under the SSP3-7·0 scenario, 22·9 per 100 000 people per year under the SSP2-4·5 scenario, and 13·6 per 100 000 people per year under the SSP1-2·6 scenario. Compared to current levels, there will be a seven-fold increase in heat-related mortality rates by 2041–2060 under the SSP1-2·6 scenario, an 11-fold increase under the SSP2-4·5 scenario, a 16-fold increase under the SSP3-7·0 scenario, and a 15-fold increase under the SSP5-8·5 scenario. When population is held constant, the corresponding increases in heat-related mortality rates by 2014–2060 will be lower: a five-fold increase under the SSP1-2·6 scenario, a seven-fold increase under the SSP2-4·5 scenario, an eight-fold increase under the SSP3-7·0 scenario, and an 11-fold increase under the SSP5-8·5 scenario. By the end of the century, the largest increase is seen under the SSP3-7·0 scenario when population change is taken into account, since this pathway projects continued high population growth in some countries (appendix 1 p 4). The relative changes with population held constant are shown in appendix 1 (p 9) and full results for each country are provided in appendix 2.

Figure thumbnail gr1
Figure 1Relative change in annual heat-related mortality rate (per 100 000 population) for each country with respect to the baseline period 2001–2020

Temporal trends in annual mortality up to the end of the century under each SSP scenario based on the GAM analysis are shown in figure 2. In most countries, burdens between the scenarios are similar up to the middle of the century, after which there is a divergence, with SSP5-8·5 and SSP3-7·0 being the most impactful scenarios and a plateauing or reduction of heat impacts under the other two scenarios. Iran is expected to have the highest heat-related death rate by far during this century. Impacts will generally be lowest in North African countries, reflecting their modest future population growth compared to other MENA countries. High population growth will contribute to Palestine experiencing a high heat-related mortality burden by the end of the century. Corresponding figures with population held constant are shown in appendix 1 (p 10).

Figure thumbnail gr2
Figure 2Annual total projections of heat-related mortality risk in each country for the four CMIP6 SSP pathways over the period 2001–2100

The rate of change in heat-related mortality rates up to the end of the century is shown in appendix 1 (p 11). In most countries the rate reduces after the middle of the century under the SSP1-2·6 and SSP2-4·5 scenarios. In the most vulnerable country, Iran, the rate of change peaks during 2061–2080, since population growth slows down after this period. In general, the box-plot error bars become wider at later time horizons, reflecting greater uncertainty in projections towards the end of century. Error bars are slightly narrower when population is held constant (appendix 1 p 12).
The results from the sensitivity analysis showed that greater heat-related burdens are estimated when heat thresholds are assumed to be at lower percentiles (85th or 90th percentiles) as a result of a greater number of hot days above the threshold, and smaller burdens are associated with the 98th percentile. Differences between countries and across SSP scenarios and time-periods do, however, remain largely consistent. Full results are provided in appendix 3.
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