網上版請按此
How Hong Kong can use advanced technologies to reduce carbon emissions
The Covid-19 epidemic will be over one day, but the global climate change issue will remain. Fortunately, there is a light at the end of the tunnel, according to the MIT Technology Review.
Earlier, the United Nations (UN) found that global temperatures could rise more than 5°C by 2100. But late last year, the Climate Action Tracker, an independent scientific analysis by two research organisations, projected that if countries around the world follow through with all the climate policies already in place, we would be on track for 2.7°C of warming this century, nearly half the rate estimated by the UN.
In line with increasingly stringent emission reduction measures in various regions and continuous decline in renewable energy prices, solar photovoltaics (PV) has become a mainstay of low-carbon sustainable energy strategies, with the cost of power generated by PV plants declining by 77% between 2010 and 2018, according to the International Renewable Energy Agency. Another intergovernmental organisation, the International Energy Agency, also predicted that the global demand for wind, hydroelectric and solar power would increase by more than 60% by 2026, surpassing fossil fuel and nuclear power.
In addition, electric vehicles have been prevailing in recent years. Data from research firm BloombergNEF shows that the global number of electric vehicles sold increased by 80% to 5.6 million last year compared with 2020. Statistics from China also aligned with the worldwide trend. According to the China Association of Automobile Manufacturers, the number of new energy vehicles newly registered surged from 650,000 in 2017 to 2.95 million last year, accounting for 11% of newly registered cars, a 151% increase from 2020.
In Hong Kong, the total number of electric vehicle registrations has also increased from just 162 in 2010 to more than 28,000 by the end of last year, accounting for 3% of all vehicles.
This is good news. But to tackle the climate crisis is an ongoing effort. The following three measures may also be considered in Hong Kong:
1) Floating Solar
In densely populated cities, it is difficult to build large-scale solar panels, however, it is a different story on water surfaces such as reservoirs.
A new floating solar plant in South Korea will be the world's largest and is expected to provide power to 60,000 people. According to the World Bank, there are more than 150,000 square miles of reservoirs globally; floating solar has giant global potential.
In Hong Kong, the Drainage Services Department and the Water Supplies Department respectively plan to install floating solar power systems on the Shing Mun River, Shek Pik Reservoir and Plover Cove Reservoir as pilot projects. In fact, there are over 20 reservoirs and irrigation reservoirs in Hong Kong. Could we explore their possibilities as well?
2) Tree Corridors
In the hot summer, sun-baked pavement and cemented areas can create urban heat islands.
Medellin, Colombia's second-largest city, has planted over 350,000 trees and shrubs since 2016, successfully creating 30 shaded "green corridors", reducing the city's temperature by more than three degrees and improving air quality at the same time. Other cities like Mexico City and Paris have also adopted this relatively cheap climate-mitigation measure.
In the past 10 years, Hong Kong has planted more than 400,000 trees in urban areas, but "green corridors" are not commonly found. Perhaps the authority should adjust their planting strategies.
3) Green Cement
The global cement production industry is estimated to create 4 gigatons every year. The production of cement requires heating limestone to over 2,000 degrees, releasing enormous amounts of carbon dioxide. A US technology company has developed cement that can be fired at lower temperatures, reducing emissions by one-third. It can also solidify the resulting carbon dioxide emitted, and lock them in the rock. The company said that if the entire industry used this method, it could lower the annual carbon emissions by 1.5 gigatons (about 4% of global emissions), while saving three trillion liters of water.
According to research by the WWF, the construction industry was the second largest carbon-emitting industry in Hong Kong. Adopting more sustainable construction technologies is one way to reduce carbon emissions.
These technologies look promising. I encourage the government to explore these options so that we can accelerate our trajectory toward a greener future.
Dr. Winnie Tang
Adjunct Professor, Department of Computer Science, Faculty of Engineering; Department of Geography, Faculty of Social Sciences; and Faculty of Architecture, The University of Hong Kong