Feel strongly about these letters, or any other aspects of the news? Share your views by emailing us your Letter to the Editor at letters@scmp.com or filling in this Google form . Submissions should not exceed 400 words, and must include your full name and address, plus a phone number for verification. As our agricultural landscapes strain to meet the needs of the growing global population, the world is realising the sheer scale of our agrifood system challenges . We are looking to the research community for future-proof strategies that benefit coastal aquaculture and high-elevation wheat production. Diversification is a powerful way to recapture agro-ecological functions lost in monocultural production and to build resilience to increasingly volatile weather and markets. Traditional production systems can provide useful models for diversification, such as the low-input, high-nutrition “co-culture” of rice and fish in Asia, and the milpa system in Latin America, where many different crop species are grown together. International research centres in Malaysia and Mexico are producing proteins and carbohydrates from the same plot of land. Many complementarities emerge when agricultural landscapes are managed to produce both these essential macromolecules. We can see this in traditional wheat-growing areas of the Nile Delta, which are confronting a growing gap between water demand and supply. Researchers are helping Egyptian wheat producers to more efficiently use water and nutrients by incorporating indoor tilapia production into their operations and using the nutrient-rich effluent to grow fruit trees and vegetables. Integrated aquaculture-agriculture is enabling these producers enhance their productivity and diversify their income streams despite degraded conditions. In Asia, scientists are quantifying the benefits of different integrated rice-fish production systems and investigating the role of emerging innovations. The next step would involve mechanisation for early planting, preventing loss to extreme heat events, and improved conservation of soil and water through integrated management. Co-design can be central to locally adapted innovation. Farmer-centric innovation models, combined with new measurement tools, allow scientific advances to benefit diverse smallholder production systems. To combat antibiotic resistance, Egyptian aquaculture stakeholders use a process called “system mapping”, which generates feasible options – rapid diagnostics, improved water management and feed storage – that maintain fish health while reducing antibiotic use. In response to the wheat supply crisis, other scientists are combining integrated crop management, soil-conserving practices, digital advisories and improved varieties. Substituting wheat flour with blended wheat flour is another response. The world is not moving quickly enough on the future-proof solutions we need. Scientists need to continue testing new research models for integrated aquatic and terrestrial production systems. Bram Govaerts, director general, International Maize and Wheat Improvement Center and A.D. White professor at large at Cornell University, and Essam Yassin Mohammed, interim director general of WorldFish and acting senior director of aquatic food systems of CGIAR Make food waste reduction scheme more rewarding In 2020, food waste made up 30 per cent of municipal solid waste in Hong Kong. In 2014, the government launched the Food Wise Hong Kong campaign, under which ambassadors have been recruited to promote the culture of making good use of food resources and reducing waste in the community. All Hong Kong residents can be appointed as ambassadors by attending at least one training workshop. While the mission of the ambassadors is critical for the city to reduce solid waste and its carbon footprint, the government website contains no information about additional support from the Environmental Protection Department for the ambassadors beyond the training workshops. In response to our inquiry on what kind of activities the ambassadors have conducted, the Environmental Protection Department said it did not require them to report the activities to the department. The scheme has declined in popularity, with the number of applications dropping from 144 in 2013 to 15 in 2021. In 2020, a university in Nanjing organised a reward scheme to encourage students to reduce food waste. On presenting empty plates after meals, participants can collect red heart stickers to redeem gifts. This year, the Communist Youth League on the mainland launched an online campaign and developed a WeChat app for participants across the nation to upload pictures of empty plates. Once the images have been verified by artificial intelligence, participants can collect credits and donate them to a charitable organisation that supports education in less developed regions. They can also celebrate their food waste reduction efforts on social media. To reinvigorate the Food Wise Ambassador scheme, the Hong Kong government should organise similar activities so participants can be recognised and rewarded for reducing food waste. Chen Yuhang and Gong Yuan, Nanjing Save up leave for long trips to cut carbon emissions Long-haul flights that generate elephantine carbon footprints seem unavoidable (“Why net-zero sustainable tourism by 2050 starts with you taking fewer long-haul flights”, November 16 ). Yet time and money permitting, why not make intermediate layovers on the way to your furthest destination, and do the same on the way back? Surely a butterfly breaking free of its Covid cocoon will find it easier to have resting stops flying in one direction and then back. My recent travels incurred less carbon guilt than they might have. Emerging starved from lockdown after three years of travel abstinence, I spent a whopping 100 days of unused leave on a “Southeast Asia unlimited” trip. After looping the vast Indonesian archipelago eastward from North Sumatra to Lombok across Java, I adventured to Borneo, city-hopped northwards from Singapore to Bangkok via Kuala Lumpur, then followed Vietnam’s East Sea coastline between Hanoi and Saigon before flying home to southeastern Australia. Lessons are being learned as the pandemic wanes. Long trips away using leave saved up during lockdown mean leaving and returning home just the once. Heading north on an outbound journey to Southeast Asia and south on the homebound trip means no doubling back. By consolidating my trips into one itinerary, I was able to minimise my carbon output. Map large dollops of your travel bucket list onto a globe using a piece of string. The most carbon-friendly multi-destination itinerary is the one that cuts the shortest length. Joseph Ting, Brisbane