Ambrogio & Gaia
A REACHOUT climate story about Milan's heatwaves
On a hot August day, Ambrogio and his granddaughter Gaia are on their way to the park.
Temperatures this week have been extreme.
‘We need some shade’, Ambrogio tells his granddaughter.
Ambrogio lives in a small apartment without airconditioning. Last night, the heat kept him awake.
‘The trees will cool us down, they always have’, he tells Gaia.
But what they saw once they arrived at the park took them by surprise…
The lake level has decreased and some trees have died due to the high temperatures in recent weeks...
The Milanese will remember 2022 as one of the hottest summers ever.
When Ambrogio was in his 30’s, these kinds of heatwaves used to be an exception.
But this has changed.
Click here to explore past heatwaves in Milan. The plots were produced as part of the REACHOUT project by TECNALIA , based on E-OBS data (daily gridded land-only observational dataset over Europe). We also developed an easy-to-use Thermal Assessment Tool to visualize heat-related data, which offers added-value information regarding the impact of heatwave events at both regional and local scale.
Because of climate change, the frequency of these heatwaves will further increase in the coming century.
Even at lower levels of global heating, in the next decades, more regular heatwaves are unavoidable for children everywhere.
For Gaia, heatwaves are going to become a more regular thing.
This is what the scientists show us for Milan…
During Ambrogio’s working life, alarming heatwave events of more than 5 days used to happen on average once every 6 years.
During Gaia’s lifetime, the frequency of these alarming heatwaves will increase.
Click here to explore future heatwaves in Milan. The plots were produced as part of the REACHOUT project by TECNALIA , based on bias-adjusted EURO-CORDEX data. We also developed an easy-to-use Thermal Assessment Tool to visualize heat-related data, which offers added-value information regarding the impact of heatwave events at both regional and local scale.
'That is why we need to act now', Ambrogio tells his granddaughter.
The sweet scent of Empress Trees surrounds them. ‘It is so much cooler in the shade’, Gaia shouts excitedly.
‘A tree we plant now, will provide shade for our children’, says Ambrogio.
And there's more...
Trees sequester carbon as they grow, thereby removing CO2 from the atmosphere and mitigating climate change.
Trees can clean the air that Milano’s 3 million residents breathe by collecting airborne particulate matter on their leaves and removing some harmful gases.
Trees can provide significant benefits for climate change adaptation:
• Trees can lower temperatures by providing shade and through evapotranspiration, thereby reducing the heat island effect and cooling the city during heatwaves.
• Trees help protect citizens from the impacts of stormwater by promoting infiltration into the ground, reducing the volume and speed of surface water runoff.
•Trees reduce the frequency and intensity of flood events by storing water in the surrounding soil and preventing erosion.
Understanding how trees contribute to mitigation and adaptation enables the city to plan for equitable increases in tree cover across different neighbourhoods in Milan.
And there is much more. Trees improve residents’ health and well-being, 'nature walks' are increasingly linked to physical and mental health benefits. Trees also provide habitat for biodiversity…
For more information, see WRI 2022 , the Global Protocol for Community-Scale Greenhouse Gas Inventories (GPC).
The urban heat island effect (UHI) is caused by concrete, stone and road surfaces absorbing energy from the sun. As a result, the urban area is significantly warmer than its surrounding rural area.
This effect is visible during daytime with temperatures up to a couple of degrees warmer than the countryside. The effect gets even larger during night-time, as the city only slowly releases its heat. The difference between the urban and rural area can reach up to 10 degrees Celsius.
For this map, the UHI was assessed based on remotely sensed Land Surface Temperatures (LST): Surface Urban Heat Island (SUHI).
The map was produced as part of the REACHOUT project by TECNALIA and CAS . Sources: Frustaci et al., 2022 .
Planting trees and creating green infrastructure is an effective strategy for reducing the urban heat island effect. Research shows that a massive implementation of green space in cities can decrease temperatures of about one degree at the local level during heat waves.
On the right you can compare the Surface Urban Heat Island effect with the percentage of green space in Milan. Green space does not only include parks, but also trees and green infrastructure like green roofs and walls.
The maps were produced as part of the REACHOUT project by TECNALIA , CMCC and CAS (% green space, based on the European Settlement Map 2017 (ESM2p5m). Sources: Colaninno, 2019 ; Nieuwenhuijsen et al., 2022 .
The availability of green space varies quite considerably between different neighbourhoods, with some people having easy access to green space, while many others have no or little access. This map shows the walking distance to the nearest green space.
The map was produced as part of the REACHOUT project by CMCC and CAS (based on the European Settlement Map 2017 (ESM2p5m). Sources: Nieuwenhuijsen et al., 2022 .
Click here to learn more about what the City of Milan is doing to improve equitable access to green areas in Milan.
Click here to learn what you can do to make the city more resilient.
