Immaculate Njuthe Maina

I had the honor of delivering my first lecture as Adjunct Research Professor at Western University, Ontario, to a full house of 300+ students. The theme: Climate Change, Global Health & One Health: lessons from the frontlines. I began with a memory. As a teenager in Cameroon, heavy rains turned my village into a floodplain. When the waters receded, disease followed, malaria, cholera, bilharzia. That night I learned the first lesson of One Health: when nature falls sick, people fall sick. My grandmother used to say: “When the soil is sick, the harvest is hungry.” Today, science confirms it. Over 50% of human diseases are aggravated by climate change. Air pollution claims 1.1M African lives annually. 30–50% of Africa’s food is lost post-harvest, fueling methane and hunger. But here is the most important truth I shared: knowledge only matters when it moves from research → policy → people. That’s why I introduced the students to the One Health Policy–Practice Ladder (OH-PPL) — a practical tool to turn science into change: 1️⃣ Diagnose the risk (floods, air pollution, food loss).. 2️⃣ Co-design solutions with communities, youth, informal sector. 3️⃣ Resource with standards, small finance, skills. 4️⃣ Implement low-cost, high-impact pilots. 5️⃣ Scale by embedding into policy and standards. In #Uganda, this ladder took solar dryers from pilots to national food safety standards, cutting food loss by 40%, methane by 90 tCO₂e/year, and raising farmer incomes by $1,800/year. In #Cameroon and #Nigeria , youth co-designed biodigesters that turned waste into cooking gas, avoided 1,000 tCO₂e, and created green jobs. The ladder works because it moves us from ideas → action → scale. The greatest innovation is not a new idea, but a tested solution scaled to serve people. To the youth: your innovation is empathy in motion don’t, wait for permission to act. To leaders: fund the ladders that turn pilots into policy, because without scale, even the best science stays in the lab. The future of health is not in theory, it is in how fast we climb the ladder from knowledge to action.