Lecture on climate change and water resources in Trentino South Tyrol for Erasmus+ High Schools students. Made by Giacomo Bertoldi, Eurac Reseach.

1. The climatic future of the Alps
Giacomo Bertoldi
Schnalstal (BZ), Italy
5 October 2022

2. Klimareport Südtirol 2018 2
tt/mm/jjjj
Climate change
From: Zebisch et al. Klimareport Südtirol. (2018);
https://hdl.handle.net/10863/7343

3. The temperature is already rising ...
2015
2003
Station Bozen
In the last 50 years Trentino Alto Adige has recorded an increase in temperatures
above the global average. Since the sixties Summers were on average warmer than
2.2°C, winters about 0.8°C
2014

4. The Intergovernmental Panel on Climate Change has developed four possible scenarios called
“Representative Concentration Pathways - RCP” .
And in the future? What scenarios are possible?

5. How will temperatures change?
2015
2003
Bolzano station
2014

6. Between now and 2050, we estimate a
further warming in summer between
about 1.4 ° C and 1.6 ° C and until
2100 even between 2.1 ° C (RCP 4.5)
and 5.4 ° C (RCP 8.5).
Summer and winter temperature increase
Winters could see an increase in
temperature in 2050 between 1.1°C
and 1.3°C and until 2100 between
1.8°C and 4.7°C.
Station Bozen

7. Precipitation does not vary much
Station Bozen
[mm]
• For most stations no
specific trends.
• In the future they do not
expect major changes,
except a slight trend of
increased rainfall in
winter
• Slight increase in heavy
rainfall at some stations

8. What do +2°C or +5°C mean?
It's like ...
"Lower the mountains"
2° ~ 300 m
5° ~ 700 m
http://lter.eurac.edu/en/
The temperature drops by about 5-6 degrees per 1000 m: how will the environment change?
The choice is between +5 or +2: go down 700 or 300 m !

9. What do +2°C or +5°C mean?
It's like ... "Migrating south"
2° From Bolzano to ...
5° From Bolzano to ...
Climate Analogous https://climate-analogues.climate.copernicus.eu/

10. Klimareport Südtirol 2018 10
tt/mm/jjjj
Impacts on
snow and ice

11. Klimareport Südtirol 2018 11
tt/mm/jjjj
Snow and ice
• Due to the higher temperatures in winter, it will
rain more and snow less.
• Snowfall will begin later, and the snow will melt
sooner. The stay on the ground of the snow will
be shorter.
• By 2100 raising the snow limit by about 700 m.
At an altitude of 1500 m this means 80-90%
less snow.
Foto G. Alberti

12. Klimareport Südtirol 2018 12
tt/mm/jjjj
Less snowfall especially at low altitude
Data show decreasing trend for fraction of snowfall in winter over the past 40 years
(-0.031±0.017 mm/cm/10y) (Bertoldi et al., 2022)

13. Klimareport Südtirol 2018 13
tt/mm/jjjj
Fewer days with snow on the ground
https://clirsnow.netlify.app/past-snow/#trends-by-season-1971-2019
EURAC dossier snow: https://beta.eurac.edu/it/dossiers/dossier-neve-alto-adige-alpi

14. Klimareport Südtirol 2018 14
tt/mm/jjjj
Glaciers melt and become smaller
Vedretta di Vallelunga
Hintereis Ferner

15. Klimareport Südtirol 2018 15
tt/mm/jjjj
South Tyrol's glaciers are shrinking
Hochjoch Ferner Vinschgau, Südtirol
1908 2018

16. Klimareport Südtirol 2018 16
tt/mm/jjjj
Glaciers become thinner
Foto C. Casarotto, G. Alberti

17. Klimareport Südtirol 2018 17
tt/mm/jjjj
Less glaciarized landscapes but ... New potential?
Circa 1900
2015
2100 ?
Cima d´Asta, foto A. Ghezzer
foto G. Alberti

18. Klimareport Südtirol 2018 18
tt/mm/jjjj
Impacts
on the water

19. Klimareport Südtirol 2018 19
tt/mm/jjjj
What is happening to our rivers? Adige catchment
• Summer: reduction of
outflows due to greater
evapotranspiration
(Adige: -20% since
1975)
Winter: increased runoff
Scenarios for the Noce Basin:
Majone, B., Villa, F., Deidda, R., Bellin, A., 2016. Impact of climate change and water
use policies on hydropower potential in the south-eastern Alpine region. Sci. Total
Environ. 543, 965–980.

20. Klimareport Südtirol 2018 20
tt/mm/jjjj
What if the glaciers disappear?
• In areas with many glaciers: first an increase
due to melting.
• In the future: decrease in summer runoff due
glaciers retreat.
• Ahrn river in St. Georgen (Bruneck):
• Glacial area 3%
• Runoff: - 5 % year; -20% summer.
• Less regular runoff: new reservoirs?
Foto G. Alberti
The most important thing is the snow!

21. Klimareport Südtirol 2018 21
tt/mm/jjjj
Water and winter tourism
• Winter tourism must deal with the uncertainty of snow. At
higher temperatures it becomes increasingly difficult even to
produce snow artificially
• 1995-2015: quintupled the cannons
for artificial snowmaking in South Tyrol
• 2007-2015: water consumption for
artificial snow increased from 5 to 7
million cubic meters -> Increase in
electricity consumption by 77% from
2005 to 2015

22. Klimareport Südtirol 2018 22
tt/mm/jjjj
• Increased water needs in agriculture (irrigation) and
tourism (artificial snow)
• Reduction of water resources (especially in summer)
• Possible exacerbation of conflicts over the use of water
resources.
• Winter: potentially more availability -> possible
advantage for hydroelectric production
Water management

23. Klimareport Südtirol 2018 23
tt/mm/jjjj
Will the risk of drought in the Alps increase?
Snow cover, December 2017
Expected to increase both extremely dry and wet months
TREND FUTURO

24. Klimareport Südtirol 2018 24
tt/mm/jjjj
Increasing drought risk in the Alps
Klimareport Südtirol, 2018
Snow cover, December 2017
Natural climate variability
+
temperature increase and
evaporation
+
decrease in snow cover
=
increased risk of drought

25. Klimareport Südtirol 2018 25
tt/mm/jjjj
Oct 2021 – Apr 2022: lack of winter snow & above-average temperature …
From ECMFW ERA 5 reanalysis - https://climatereanalyzer.org/ - Climate Change Institute – University of Maine

26. Klimareport Südtirol 2018 26
tt/mm/jjjj
Spring 2022 drought in the Adige Basin

27. Klimareport Südtirol 2018 27
tt/mm/jjjj
May-June 2022: Below average precipitation and extreme high temperature …
From ECMFW ERA 5 reanalysis - https://climatereanalyzer.org/ - Climate Change Institute – University of Maine

28. Klimareport Südtirol 2018 28
tt/mm/jjjj
ADO Portal (Current Status Map) https://ado.eurac.edu/
https://ado.eurac.edu/
Am wichtigsten ist der Schnee!

29. Klimareport Südtirol 2018 29
tt/mm/jjjj
Evaporation and dry days: Vinschgau
Difference 2100-2080 vs. 2010-1990
• Greater drought on southeast-facing slopes below 1500m
• http://webgis.eurac.edu/hydroalp/

30. Klimareport Südtirol 2018 30
tt/mm/jjjj
Impacts on
vegetation

31. Klimareport Südtirol 2018 31
tt/mm/jjjj
• Longer vegetative cycles.
• Pollen season is anticipated.
• Increased evapotranspiration and
water consumption of plants.
Flora and fauna
Drought summer 2022 in Trentino
Forest damage October 2018 in Trentino

32. Klimareport Südtirol 2018 32
tt/mm/jjjj
• More damage caused by pests (midges, gray
mold, powdery mildew, late blight). Parasites
survive the milder winters and reproduce in
more generation's cycles;
• Orchards and vineyards at ever higher altitudes;
Apple orchards at 1000 m in Val Venosta.
• Changes in the traditional landscape.
• Opportunities for areas now underexploited?
(Valley Giudicarie, Valsugana)
Agriculture

33. Klimareport Südtirol 2018 33
tt/mm/jjjj
Agriculture: new possibilities?
Quota
New areas at higher altitudes become usable
From project Eurac REBEKKA Interreg IT-AT (L. Egarter)

34. Klimareport Südtirol 2018 34
tt/mm/jjjj
Natural hazards

35. Klimareport Südtirol 2018 35
tt/mm/jjjj
Water and Health
• In summer, heat waves and tropical
nights pose a major danger to human
health
• Spread of ticks at higher altitudes (up to
1600 m) and the diseases transmitted by
them
• Stable spread of tiger mosquitoes and
other species that could transmit
tropical fevers.
•

36. Klimareport Südtirol 2018 36
tt/mm/jjjj
Natural hazards
• Due to melting glaciers and permafrost the soils are
more unstable, thus increasing collapses and
landslides.
• Melting processes release sediments that can cause an
increase in landslide activity and acceleration of basin
burial.
• Flood risk reinforced by the increase in heavy rainfall
caused by the fact that at high altitudes it snows less
and rains more.
• Possible future danger: floods caused by glacial lakes
outburst.
Marmolada, 3.7.2022
Dimaro, Val di Sole 28.10.2018

37. Storm Vaia in 2018
• Extreme event but difficult to attribute to climate change.
• With more energy in the climate system, however, it is likely that events of this type
will become more frequent in the future (e.s. Alluvione Marche 2022)
Baselga di Piné, 29.10.2018

38. Klimareport Südtirol 2018 38
tt/mm/jjjj
What can we do?
Mitigate and
adapt

39. Klimareport Südtirol 2018 39
tt/mm/jjjj
Reduction of emissions !
Mitigation measures

40. Klimareport Südtirol 2018 40
tt/mm/jjjj
o Investment in water-saving measures e.g. through forms of
efficient irrigation in agriculture, optimization of networks
and consortia or creation of new reservoirs
o Possible different management of hydroelectric reservoirs
also for irrigation and hydro/drinking use.
o Consider climate change in management and hazard plans
and in the granting of concessions rules.
Water management
Adaptation measures

41. Klimareport Südtirol 2018 41
tt/mm/jjjj
A look at the world
Mountains are
«Water towers of the world» :
Bompan,E.,. Iannelli M. Water grabbing. Nuove guerre per l'accaparramento dell'acqua
Viviroli, D., Weingartner, R., 2004. The hydrological significance of mountains: from regional to global scale. Hydrol. Earth Syst. Sci. 8, 1017–1030.
Lago Aral 1989 - 2014
Responsibility of those who are upstream

42. Klimareport Südtirol 2018 42
tt/mm/jjjj
Resources
Dati fiumi: www.floods.it
Piano Gestione Acque: http://pguap.provincia.tn.it/#
Clima Trentino: http://www.climatrentino.it/
Clima Euregio: http://www.clima-alpino.eu/
Dati Meteo: http://storico.meteotrentino.it/
Analogie climatiche: https://climate-
analogues.climate.copernicus.eu/
Report climatico Alto Adige:
https://www.eurac.edu/it/research/mountains/remsen/
projects/Pages/klimareport.aspx
Dossier Neve:
https://beta.eurac.edu/it/dossiers/dossier-neve-alto-
adige-alpi
Thank you for your attention!

44. Thank you for your attention!