The Chinese mainland has started earnestly on its journey to deal with waste. Hong Kong and Macao must continue to advance to keep pace.

Since 2007, leading mainland cities have piloted garbage sorting plans, culminating in the mainland's first mandatory program starting on July 1 last year in Shanghai, which has a population of 24 million.

Shanghai residents had several months to get used to placing waste in separate bins before the mandate became effective. The authorities ran a massive public education campaign on what to put where and about fines for noncompliance. After some initial confusion, most people got used to it, although there are still laggards and the authorities are also having to deal with kinks in the system.

Beijing, a city with 21 million people, imposed its mandate on waste separation on May 1. All the other leading cities, including Guangzhou, are at various stages of readiness for implementing mandatory waste separation this year, and smaller cities are in line to follow suit by 2025.

In 2017, the mainland shocked the world by putting limits on the import of recyclables, which it progressively tightened. It is only willing to take the best quality recyclables. With its own mountains of waste, it makes sense to not be the dumping ground for other people's rubbish.

The latest campaign is reducing food waste - referred to as the Clean Plate 2.0 campaign. There are several aspects worth observing.

There is the indisputable narrative that wastage of a precious resource is inexcusably bad. There is a social-economic dimension to wasting food when many people don't have enough to eat, and it harms the environment too. Moreover, treating and disposing of waste cost a lot of money for individuals, businesses and the State.

Accompanying the "don't waste" message is that of food security. China has the largest population in the world with 1.4 billion people, thus, feeding the nation has always been a top priority. In other words, food security is vital for everyone's well-being.

To keep everyone fed requires enormous domestic efforts, as well as a very large volume of imports. With climate change, which affects weather patterns and therefore food production, and geopolitical considerations that relate to food imports, it is imperative to reduce food waste.

Food waste is not just what we throw away in the kitchen or from dining. Food "loss" happens all along the supply chain from where it is grown or produced, during transportation or storage, and ordering too much food that then has to be thrown away. Better management in food-related businesses will help to minimize food loss.

Hence, policymakers now talk in terms of "drastically reducing" food wastage. Targets and timelines can be expected in the foreseeable future, perhaps with the 14th Five-Year Plan (2021-25).

Moreover, COVID-19, the coronavirus that has decimated so many economies around the world, has brought a change in food consumption habits. People are cooking more at home and at the same time, they are also ordering takeouts from restaurants and eateries that have had to adapt to stay-at-home circumstances. In parallel, COVID-19 is making people think more about health and well-being.

The combination of pressure from the government to reduce food wastage and from COVID-19 in the intake of food in quantity and quality terms is stimulating all manner of digital innovation. Being more efficient all along the food chain is crucial to those in the food business. They also need to meet customers' demands for "smart" ways to make life easier. The latest demands relate to information about food portions and nutrition.

In other words, China is becoming a trendsetter.

The special administrative regions of Hong Kong and Macao are physically small by comparison to the mainland's major cities. Being SARs, they are not bound by the mainland's waste policies, although like cities everywhere, waste is a major challenge for them, too.

Hong Kong has a broad waste management plan, including in food waste reduction. Its current edge is in specific infrastructures, such as T-Park, which is the world's largest sewage-sludge-to-energy plant; WEE Park, which deals with waste electrical and electronic equipment and recycling; and O PARK, which is the city's first 200-tons-per-day food-waste-to-energy plant. It is also building the city's first 3,000-tons-per-day waste-to-energy plant to treat municipal solid waste.

Hong Kong has not focused on mandatory waste separation. Instead, it is relying on public education to promote sorting but it has put forward a mandatory MSW charging program. By making people pay for their waste to landfill, the authorities expect it will have a major waste reduction outcome - as in many overseas jurisdictions. Under the program, there is no charge for recyclables that are set aside for collection.

Hong Kong's legislators decided not to continue scrutinizing the MSW bill because time was running out, as the legislative term was coming to an end. Now that the term has been extended for a full year in light of COVID-19 and the original election date had to be postponed, it would make sense for the government and legislators to pick up the bill again to get it done when the legislature resumes in October.

For Hong Kong. the MSW bill is the linchpin for the city to move ahead on waste management, and all sides of the political divide should support it since the business sector and community have been preparing for some time. Hong Kong should give this matter the highest priority as landfills are bursting.

Clean Plate 2.0 could also be adapted for Hong Kong. Food waste reduction is just the sort of thing that could unite the community.