Current and Future Human Exposure to High …
7
3 Current and Projected Human Health Impact of Hot
Days in the Algarve
We calculated projections of future mortality risk for all municipalities of the Algarve
region using spatial statistical methods, historical measurements and future temperature projections under RCP4.5 and 8.5 (IPCC 2013), to model non-accidental
mortality risk (% increase of deaths) as a function of the number of hot days
(maximum temperature above 30 °C) and sociodemographic variables, namely %
elderly municipal population (residents above 65 years old), % municipal per capita
purchasing power and % municipal urban area.
Currently, average annual maximum temperature varies between 15.6 and 23.4 °C,
influenced by mountainous areas along central Algarve and the Atlantic Ocean in
western Algarve (Barlavento) whereas the highest values occur along the Guadiana
river in eastern Algarve (Sotavento).
Under climate change scenarios, the Sotavento area may come to experience an
increase in average maximum temperature close to 4 °C by the end of the century.
Tropical nights (days with minimum temperature exceeding 20 °C) range currently
between 9 and 16 days but can increase up to 66 more days under RCP8.5 scenario
by the end of the century in coastal Sotavento, comparatively to the current situation.
Concerning the number of hot days, considerable increases are projected for
the end of the century throughout the region. Northernmost Sotavento, near the
Guadiana river, experiences currently around 70 days a year, but this count can rise
to approximately 50 more days (Fig. 1).
A higher incidence and longer average duration of heatwaves is projected, especially in inland areas. In the last 30 years, 2–13 heatwaves were registered, with an
average period between 6 and 9 days (Barlavento and Sotavento, respectively). Up
to 200 heatwave events may occur in 2071–2100 (RCP8.5), with an average period
longer than 4 days, compared to the current period.
According to our current mortality model, Algarve municipalities had, on average,
2% of non-accidental heat-related mortality, during the reference period adopted
(1991–2003).
In line with projected increases in hot day counts, mortality projections (Fig. 2)
signal a progressive rise in mortality risk over the considered periods, under scenarios
RCP4.5 and RCP8.5, with the risk gradually increasing from east to western Algarve.
The worst situation (near 8% increase) is expected by the end of the century under
RCP8.5, at the north-eastern tip of the territory.
4 Policy Recommendations
To transpose our findings into policy recommendations, projected impacts and adaptation measures were evaluated in the light of existing evidence, and comprehensive stakeholder consultations were performed. Resulting from this process, targeted
7
3 Current and Projected Human Health Impact of Hot
Days in the Algarve
We calculated projections of future mortality risk for all municipalities of the Algarve
region using spatial statistical methods, historical measurements and future temperature projections under RCP4.5 and 8.5 (IPCC 2013), to model non-accidental
mortality risk (% increase of deaths) as a function of the number of hot days
(maximum temperature above 30 °C) and sociodemographic variables, namely %
elderly municipal population (residents above 65 years old), % municipal per capita
purchasing power and % municipal urban area.
Currently, average annual maximum temperature varies between 15.6 and 23.4 °C,
influenced by mountainous areas along central Algarve and the Atlantic Ocean in
western Algarve (Barlavento) whereas the highest values occur along the Guadiana
river in eastern Algarve (Sotavento).
Under climate change scenarios, the Sotavento area may come to experience an
increase in average maximum temperature close to 4 °C by the end of the century.
Tropical nights (days with minimum temperature exceeding 20 °C) range currently
between 9 and 16 days but can increase up to 66 more days under RCP8.5 scenario
by the end of the century in coastal Sotavento, comparatively to the current situation.
Concerning the number of hot days, considerable increases are projected for
the end of the century throughout the region. Northernmost Sotavento, near the
Guadiana river, experiences currently around 70 days a year, but this count can rise
to approximately 50 more days (Fig. 1).
A higher incidence and longer average duration of heatwaves is projected, especially in inland areas. In the last 30 years, 2–13 heatwaves were registered, with an
average period between 6 and 9 days (Barlavento and Sotavento, respectively). Up
to 200 heatwave events may occur in 2071–2100 (RCP8.5), with an average period
longer than 4 days, compared to the current period.
According to our current mortality model, Algarve municipalities had, on average,
2% of non-accidental heat-related mortality, during the reference period adopted
(1991–2003).
In line with projected increases in hot day counts, mortality projections (Fig. 2)
signal a progressive rise in mortality risk over the considered periods, under scenarios
RCP4.5 and RCP8.5, with the risk gradually increasing from east to western Algarve.
The worst situation (near 8% increase) is expected by the end of the century under
RCP8.5, at the north-eastern tip of the territory.
4 Policy Recommendations
To transpose our findings into policy recommendations, projected impacts and adaptation measures were evaluated in the light of existing evidence, and comprehensive stakeholder consultations were performed. Resulting from this process, targeted