Life in a modern city like Hong Kong is easy and comfortable. But that superficially easy life is reliant on a complex supply system which brings in water, food, energy and numerous kinds of goods day in and day out. This system is immeasurably complicated with numerous links, thus is vulnerable in many ways. A city like ours cannot survive with resources from its own land, but must connect itself to multiple sources of material and energy from faraway lands. It is in this background that we should ponder how climate change would affect Hong Kong.

“… winter might disappear in urban areas before the middle of the century.”

The Hong Kong Observatory has carried out a number of studies into the future climate of Hong Kong. The obvious thing is that it will warm up. Previously we projected that winter would probably disappear by the end of the 21st century. But more recent analyses showed much more rapid warming, mostly likely to be the consequence of increasingly dense urban development. Now it seems that winter might disappear in the urban areas before the middle of the century. While it is good news to those who don't like cold days, it is bad news for the old and the weak living in tiny rooms in densely built areas. They will have to face stuffy, damp and hot days and nights in the extended summer. This is going to be a significant social and health issue.

The other consequence of climate change is a higher frequency of droughts and floods in Hong Kong and the nearby region. In the great drought of 1963, we lived through a period with 4 hours of water supply every 4 days. Such harsh days disappeared after we secured water supply from Dong Jiang in Guangdong. But when the whole region goes dry again in the future, the competing demand for water from the much bigger population in Pearl River Delta region could mean restricted water supply returning. The service industry including tourism is a heavy user of water. Restricted water supply would have a serious impact on the economy.

“the consequence … is a higher frequency of droughts and floods in Hong Kong”

Now let us think about the food supply to Hong Kong. The cost of living in Hong Kong has been kept rather low partly due to the stable supply of cheap food from China mainland. However, the China Meteorological Administration has estimated that, owing to climate change, the total food production in China mainland could decrease by 5-10% in the next few decades and by up to 37% in the second half of the century. In that situation, would Hong Kong continue to be able to enjoy the cheap food it has become used to? Some might say, "No problem, we'll buy food elsewhere in the world". Unfortunately, decreased food production will be a global phenomenon. Hong Kong does not enjoy any special privilege in terms of access to food.

According to Nobel Peace Prize 2007 winner Intergovernmental Panel on Climate Change, that human beings caused the current climate change through the additional emission of carbon dioxide and other greenhouse gases into the atmosphere is unequivocal. This is due to the burning of a vast amount of fossil fuels including coal, petroleum and natural gas to produce energy, in connection with transport, running of houses (lighting, heating, air-conditioning, cooking, pumping water, etc.) and manufacturing. It is truly worrying that half of the extra carbon dioxide in the atmosphere was added to the atmosphere in the last three decades, during which materialism and consumerism drove up demand for comfort and goods and thus the use of energy. And the rate is still accelerating!

“…half of the extra carbon dioxide in the atmosphere was added in the last three decades”

Climate change is a global problem but the solution has to come from the individuals changing their values in life and their life-style. Thrifty is an old-fashioned word but it is exactly what we have to place a lot of value on nowadays in order to combat climate change effectively. Use or own less of everything that you desire. Then less energy would be required, and less carbon dioxide would be emitted. That way we would at least give the Earth’s atmosphere a chance to take a rest and hopefully recuperate.

Climate change is global. The solution is local, everywhere.