Expo 2020 Dubai features eye-catching structures dubbed energy trees, as shown on Tuesday. WANG DONGZHEN/XINHUA

DUBAI－Upon entering the Sustainability Gate of Expo 2020 Dubai, the first thing you will see is a forest of "energy trees".

As many as 18 energy trees rotate their large crowns to face the sunlight just like sunflowers. Behind the energy trees, a giant canopy commands a space of over 6,000 square meters.

The pavilion, also known as Terra, is one of three major pavilions that embody the three subtheme - opportunity, mobility, and sustainability－of the expo, which runs until March.

The architects of Terra spared no effort to make the pavilion aspirational of sustainable living.

Inspired by the drought-tolerant Ghaf tree, the national tree of the United Arab Emirates, the pavilion applied the latest technologies to capture energy from sunlight and fresh water from the air.

On the energy trees and 130-meter-wide canopy, there are 4,912 solar panels that help generate 4 gigawatt-hours of electricity every year－enough to charge more than 900,000 smartphones.

The China Pavilion, one of the largest national pavilions and a must-see at the expo, is a shining champion of sustainability.

Similar to Terra, the "Light of China" adopted environmentally friendly technologies to reduce carbon footprint.

It also showcases many Chinese innovations in this area and China's resolution to contribute to building a sustainable future for the world.

At the Netherlands Pavilion, an enclosed water, energy and food system showcased a high level of self-sufficiency.

One of the most innovative features of the pavilion is the translucent and colorful solar panels covering the roof, which allow in sunlight at the wavelengths plants require for photosynthesis.

The pavilion has also put up an 18-meter-high vertical farm at the center, on which more than 9,000 edible plants such as asparagus, basil, and mint are carefully cultivated and then harvested for the restaurant.

A staff member at the pavilion said water collecting devices here can extract up to 1,300 liters of water from the air, which is used to irrigate the plants on the "food cone" and purified into drinking water for guests.

The architecture of the pavilion is not intended to be a visual spectacle, but to support its function as a "harvesting machine" and to reinforce the sustainability message.

The pavilion was built from steel that will be reused once the expo is over. The walls are made from steel sheet piling and the roof from steel tubes, while concrete was avoided in the pavilion foundations.

"Being a temporary pavilion, one of the most important things to us is that everything would be taken away again, and returned to the place what it used to be," the staff member said.

The Germany Pavilion also provides visitors with a great experience in sustainability innovation.

Officially dubbed "Campus Germany", the pavilion focused on "edutainment". It mimics the experience of college, where "students"－children or adults－can learn about German innovations and solutions in the field of sustainability.

After visitors get "enrolled", they will first come across a huge ball pit filled with 100,000 balls. Each ball contains a story, a statistic, or an idea about environmental protection. Visitors can pick a ball and place it on one of the scanners to view a short presentation.

'Amazing' experience

The Campus Germany tour ends with an inspiring "graduation" ceremony. After learning many things about sustainability, visitors sit on swing seats and are given the task of making the seats swing together, marveling at the incredible results they can achieve together.

The message is clear: If everyone works together, we can solve the pressing problem of climate change and achieve sustainability.

"The experience is amazing. Usually, when they talk about climate change or environmental problems, the tone is very serious. But here at the German Pavilion, I find it can also be promising and hopeful," said Joshua Armstrong, a visitor from the United States.

Walking inside the Singapore Pavilion is just like walking inside Singapore, the garden city. Lush plants, trees and shrubs have become integral parts of the pavilion.

When visitors walk upward along the spiraling galleria, it is lined with gardens and trees.

The self-sustaining pavilion is powered by solar panels on the glass roof. Saline water is drawn from underground and desalinated to irrigate all the plants. The pavilion uses mist fans to spray small water droplets to significantly cool down the venue by 6 to 10 degrees Celsius, so there is no need for air conditioning, even though it is located in a scorching desert in Dubai.

Calling it an "oasis in the desert", a staff member at the Singapore Pavilion said: "It showcases the coexistence of architecture and nature." It demonstrates that buildings can be designed as responsible and sustainable for the environment, achieving net-zero energy and water use in the desert.