 All countries face the challenge of a warming planet. The IAEA helps member states meet this challenge by using nuclear science and technology to monitor, mitigate, and adapt to climate change. Effective climate action requires reliable data. Countries use nuclear techniques to monitor and measure emissions of CO2 in the air and its absorption in the sea. Using acidification threatens marine ecosystems and the livelihood of coastal communities. Nuclear techniques can also help map, date, and assess the quality of freshwater resources, and they can help identify threats to ecosystems. Such data help policymakers take informed decisions about climate change. Countries also need to mitigate the effects of climate change. Assistance on energy planning helps to identify forms of low-carbon electricity that are most suitable for each country. This includes nuclear power. During operation, nuclear power releases almost no greenhouse gases. It can replace high-carbon energy sources to reduce greenhouse gas emissions. The IAEA provides guidance on establishing and expanding nuclear power programs. It helps to ensure such programs are safe, secure, and sustainable, and it supports research and development on advanced technologies such as nuclear power, sustainable for thousands of years. Countries also need to adapt to environmental change. Climate-smart agriculture and resource management developed with nuclear technology helps cope with a warming planet. Plant breeding based on nuclear science produces crops that thrive in extreme climates, a new strain of rice to grow in extremely salty waters, or a type of barley ideal for high altitudes. The agency also advises on countering biodiversity loss due to climate change and reducing the impact of severe weather on energy systems.