Over the next five years CEH will deliver its strategy, Meeting the Challenges of Environmental Change, by Science Areas underpinned by Monitoring & Observation Systems and Environmental Informatics, through Business and Policy Innovation, and Public Engagement. Natural hazards have been identified by the National Security Review as some of the most significant risks to the UK in terms of economic, social and environmental consequences. Natural hazards are increasingly a concern for humanity, as both the rate and impact of natural disasters are rising because of increased societal vulnerability, caused by trends in climate, population growth, urbanisation and land-use. The over-arching science challenge is to increase our understanding of the nature of threats from natural hazards, to improve our predictions and forecasts of the onset, frequency, magnitude and duration of such events. The knowledge and methodologies developed will allow us to better mitigate the impacts on people and the environment, thereby improving our management of natural hazards. CEH plays a vital role in understanding the nature and threats that natural hazards pose by developing the underpinning science to understand and reduce their damaging impacts, and to support the implementation of mitigation strategies. The prediction of hydro-meteorological, biological and air quality hazards will facilitate the design of management systems and improve societal resilience to extreme events. The hazards include floods and droughts, threats from parasites, pathogens and invasive non-native species and threats from natural air pollution incidents.