 The International Atomic Energy Agency runs a range of unique laboratories that drive sustainable development. These 12 high-tech facilities in Austria and Monaco are using cutting-edge science to address some of the biggest challenges faced by humanity. Nuclear scientists know that studying our world at the atomic level can give us the insights we need to unlock the planet's secrets. Because you can't solve a problem, you don't understand. The nuclear application labs are focused on applied research into human health, food security and environmental protection. They are distinct from the IAEA facilities that are used in the search for traces of undeclared nuclear activities. From preparing for the next pandemic, to tracking the sustainability of our water supplies, to tracing contaminants in global food chains, research at the atomic level can give us precise information about our complex natural world. For example, researching marine health, like monitoring the current ocean acidification crisis or assessing the movement of plastics through fish and onto our plates. Nuclear scientists are also at the forefront of research into climate-smart agriculture techniques, such as breeding drought-resistant and high-yield plants or examining soil to determine the optimal amount of water or fertilizer. Some of these labs are run jointly with the Food and Agriculture Organization of the United Nations. They undertake vital research and testing to enhance agricultural production and food security and to help combat major zoonotic diseases such as COVID-19 and Zika. They run the agency's sterile insect program, which uses radiation as a form of insect birth control, naturally suppressing the population of major invasive pests like fruit flies without the use of pesticides. Radiation therapy is an essential tool in modern healthcare, and the IAEA Dosimetry Lab helps set international standards for safe and effective radiotherapy. The IAEA's nuclear application laboratories provide all these technical and environmental services, and many more, at the request of member states. The discoveries that are made and techniques that are developed in these laboratories are shared with the world, helping to drive sustainable development. Because to address the big problems, we have to start small.