Heat symposium July - report

The heat symposium in Amsterdam in July showcased current research and solutions to combat urban heat stress. We have many policies and information available to help combat heat, with the most important being the national heat plan. However, it is not always implemented everywhere yet. If we can reduce heat stress, we can also help reduce night heat stress when buildings do not cool down sufficiently and people suffer from lack of sleep, loss of productivity and concentration, stress, and in the worst cases death. The link to socio-economic status is also clearly mapped, and we see worse conditions in areas with lower socio-economic status (in Dutch: armste wijken zijn de warmste wijken). The question has moved to what can be done as implementable measures, as we know where help is needed most. This event highlighted both green infrastructure measures, and cases where GI was not possible. 

There are new designs for mobile greenery. While these may not be ideal for plants to exist, they have proven to be effective to reduce experienced temperatures. WUR also showed different design options and how larger trees once again provide larger benefits in terms of shade, water retention, and biodiversity.

 

 

Thermal walk research showed that 10% more greenery led to about 0.5 degrees Celsius cooling, and the experienced temperature in shaded areas is about 10-17 degrees Celsius less, meaning greenery can make a big difference.

Still, many inner city buildings are several floors high and thus out of range of most trees. GI cannot solve everything in these cases. Issues mentioned included:

• Inhabitants who rent properties and have limited options to alter their living space
• Regulations prohibiting outside awnings or even the possibility of opening windows
• Housing corporations pointing towards the lack of heat stress data and therefore no reason for action
• People cannot sleep in their bedrooms with 29 degrees Celsius and move to the kitchen or hallway 

This called for additional measurements within these high rise buildings. After measurements and interviews it was found that: 

• Rental housing is 1-2 degrees Celsius warmer than privately owned housing
• Measures outside windows are exponentially more effective than inside
• Heat labels can help implement appropriate measures

Aside from technical measures, there was also a clear call to be a humane citizen and check on your neighbours during a heatwave, especially if they are older adults or have a disability. A clear actionable point!