How to cut carbon emissions and decrease urban heat stress?
October 19, 2019
Even though the indigenous Ghaf tree is an environmental and cultural symbol in the UAE, its potential in urban areas is not fully explored.
The indigenous Ghaf tree is chosen as the theme for the Year of Tolerance 2019 in the UAE. Not only does this native desert species have a cultural and heritage significant in the nation, it is also low in water consumption and can help to cut carbon emissions.
In the past few years a lot of effort has been put into protecting the species and increasing their numbers. But why aren’t we using it to green all our streets and neighbourhoods? This tree can provide much needed shade and relief from heat during summer months.
We spoke to the Give a Ghaf tree planting program, to learn more about the Ghaf and its use in public spaces.
In 2008, the Ghaf tree was declared the national tree of the UAE. This thorny, evergreen tree is a part of the tradition and history of the UAE. Almost every part of the plant has a purpose. The leaves are used as fodder and parts of the bark were used for medicinal purposes. The lush canopy of the tree creates a microhabitat for birds and insects.
Apart from its traditional values, the Ghaf is a drought-tolerant desert tree that requires only about 60L of water per day. Ranging between a height of 3-5m, it can have roots as deep as 30m and is able to survive through the harsh summer months.
The Ghaf tree can also help to mitigate CO2 emissions, which is proved to be a leading cause of climate change. Each tree can sequester up to 34.65 kg of CO2 emissions per year.
Recent global climate negotiations are pushing all countries to take more aggressive steps to reducing their carbon footprint. Expanding the planting of Ghaf trees should be recognized as a viable solution to not only cut carbon emissions but also protect the culture and tradition of the UAE.
The Give a Ghaf initiative is a local Ghaf tree planting program by Goumbook that is doing just this. Their exemplary projects have helped to raise awareness of the benefits of the Ghaf and encourage people to plant more Ghaf trees.
Ghaf trees are naturally occurring in the desert regions and are not easy to find in the city. There are some streets and parks that use Ghaf trees for landscaping. Abu Dhabi and Al Ain are pioneers in the practice of incorporating Ghaf trees across the Emirate. But why is this important?
Most urban areas experience warmer temperatures as compared to the outskirts. This is known as urban heat island (UHI) effect. This is mainly caused due to the modification of land surfaces as a result of concentration of buildings and infrastructure in cities. Its impact is felt most during summer or winter seasons with temperature variations of up to 12°C. In hotter climates such as what we have in the UAE, this increases cooling demand in summer and consequently the energy needed to meet this demand.
Overall, Urban Heat Island effect is an unavoidable phenomenon that occurs in almost every city and needs to be mitigated. Some mitigation measures include using light colored surfaces to reflect heat, planting more trees to absorb CO2 and building more open green spaces for heat relief.
In the UAE, using the Ghaf tree in urban landscaping is a sensible solution to mitigate urban heat island effect because of its low water needs, perennial nature and wide canopy for providing shade. Additionally, it can also help to cut carbon emissions. Despite this, the Ghaf is not a popular choice in urban landscaping.
Tatiana Antonelli Abella, founder and managing director at Goumbook, tells us about some of the challenges they have faced in planting Ghaf trees in public areas.
First, if a row of trees needs to be planted along the side of the road or within the median, there needs to be enough space for the roots to grow and the tree to expand during to full maturity. Most roads in the UAE don’t have enough space to support this.
Second, the aesthetic that is sought after by most landscape architects seems to be of flowering plants and trees which may not be water efficient in the hot climate we experience in the UAE.
Even so, there are spots where the Ghaf tree has been planted in public areas. The ‘Give a Ghaf’ initiative has been involved in some good projects that show us how the Ghaf can be used in public areas.
Ajman municipality has planted 2000 Ghaf trees within the intersection that falls on the Sheikh Mohammed Bin Zayed Road. This buffer area within every clover leaf along highways is usually vacant and sandy. Once the trees are fully grown this green patch will be a big contrast to the sand dunes along the rest of the highway.
A DEWA building in Dubai Healthcare City has planted a few Ghaf trees along its boundary wall. This is a great use of ‘buffer’ space around heavy infrastructural buildings which is not safe for any other.
Ghaf Trees in Dubai Health Care City. Image credit: Goumbook, Dubai.
About 50 Ghaf trees have been planted on within the median on the road leading up to the entrance of Dubai South. The median is wide enough to support these trees and provides much needed relief and soil stability within this upcoming area which is currently is large dusty ground.
Trees planted in Dubai South. Image credit: Goumbook, Dubai.
Promoting Ghaf trees within urban limits is one of the most resourceful ways to reduce carbon emissions and mitigate urban heat island effect.
Note: A shorter version of this article was first published in The National earlier this year.