Options to reduce the consequences of climate change generally fall into four broad categories: 1) mitigation—efforts to reduce greenhouse gas emissions; 2) adaptation—increasing society’s capacity to cope with changes in climate; 3) geoengineering or Earth manipulation—additional, deliberate intervention in the Earth system that tries to counteract some of the impacts of greenhouse gas emissions; and 4) pursuit of additional knowledge—efforts to understand more about the climate system, our impact on it, the consequences, or the response options themselves.

Scientific evidence relating to the climate system and the impact that people might be having on it spans dozens of fields of study and includes work from tens of thousands of individual scientists. The evidence comes from decades of intensive research and is based on observations, field and laboratory experiments, and model simulations. 

This memo considers best practices in the assessment process, compares best practices with recent high-profile climate assessments, and identifies overarching scientific conclusions. 

Water is simultaneously a resource and a threat. It is centrally important to every aspect of socioeconomic wellbeing and water becomes a hazard when there is too much, too little, or if the quality is poor. The opportunities and challenges posed by water are especially acute at the coasts, which are both major resources and often highly vulnerable to extreme events. Coastal communities are also particularly sensitive to changes in land use, population distributions, and climate. This memo identifies seven ways to enhance coastal risk management.

The weather, water, and climate community relies on the radio frequency spectrum for two vital functions: (1) to observe the earth (e.g., with satellites, weather radars, and wind profilers) and (2) to transmit data about the earth system to meteorologists, hydrologists, emergency managers, and other scientists throughout the country. These uses of radio frequencies benefit a wide range of social and economic sectors by supporting operational services that protect life and property and by helping advance scientific understanding of the earth system. 

Earth observations, science, and services (Earth OSS) inform and guide the activities of virtually all economic sectors and innumerable institutions underlying modern civilization. This AMS Policy Program memo describes Earth OSS and illustrates how Earth OSS are a fundamental component of efforts to meet basic human needs including food, shelter, energy, health and safety. At the same time, the opportunities for societal benefit from Earth OSS are increasing.