Researchers find high temperatures in neighborhoods without shade such as industrial areas – and cooler near the forests in the west
The Jerusalem municipality has mapped out for the first time the temperatures in the city streets as part of a plan to deal with the climate crisis. Temperatures in the western part of the capital are lower, and the closer you get to East Jerusalem – an area with fewer trees and where the climate is drier – the higher the temperature.
The conclusions of the climate survey will serve the city to formulate policy in the face of increasing temperatures, and for allocating resources to the hotter parts of the capital, which need solutions to lower the heat load. Solutions include planting trees, putting up shade in public areas and green construction.
The mapping was conducted using satellites by a team headed by Prof. Oded Potchter of the geophysics department at Tel Aviv University. The preliminary findings show a number of centers of exceptional heat, mostly in industrial areas such as in Talpiot and Atarot, as well as in neighborhoods in the eastern part of the capital.
Most heat islands are created because of a lack of shade. In general, vegetation, concentrations of trees or tall buildings create shade. In such places the heat is stored during the day in the concrete and is released at night. This is why, even though the surrounding temperatures are low – the public spaces do not cool down.
“The forests west of the city are its air conditioner, they moderate the temperature and increase the humidity,” said, Miri Reiss, the environment commissioner in city hall. In addition to vegetation, Reiss said other factors influence temperatures too. “ We need to give preference to building materials that accumulate less heat and reflect more light into the public space. Roof tiles are something very inappropriate for a hot climate, so neighborhoods such as Nahlaot or Baka, which have a lot of tiled roofs, are hotter. We expect there will be more hot days of over 35 degrees Celsius [95 degrees Fahrenheit] and fewer days of transitional seasons, and we are working on plans for street acclimatization,” Reiss added.
The city sees great importance in cooling things down – forecasts are for temperatures in Jerusalem to rise by three to four degrees Celsius within a few decades and will reach levels similar to Be’er Sheva today. As part of these efforts, the city hopes to map out the temperatures to the level of every street – to improve the infrastructure needed to reduce the heat. “Even the direction of the street – whether it faces north, south, east or west – affects the temperatures,” said Reiss. Encouraging more tall construction provides more shade and more wind, which can be pleasant in the summer but dangerous in the winter, she added.
Reducing the heat islands is also intended to make the streets more suitable for pedestrians and bicycle riders. The acclimatized street needs to be adapted for walking, bicycles and to do this it needs more shade, she said. “The city architect has issued instructions as how to create a continuum of shade, and the most effective is natural shade.”
Professionals in city hall recommend preserving forested spaces in the capital and to continue looking for solutions for shade and other cooling. This is a major recommendation in light of the building plans that now threaten the Lavan Ridge west of the city and the Jerusalem Hills.
Jerusalem Mayor Moshe Leon said “the importance of preserving the climate is essential and not just a headline. The importance is clear to all of us. With the goal of reducing the influence of climate change in the urban space, we are acting as much as possible to promote plans, such as the climatized streets initiative. In this way, city residents and visitors will enjoy a cool city and clean and clear mountain air, along with protecting the environment and preventing climatic effects as a result of the global climate crisis.”