Since 2017, we have chaired popular sessions focused on climate extremes, mechanisms and attribution. We have typically led 3 sessions per year, attracting submissions from many of the top scientists in this rapidly evolving discipline. This year, however, we would like to take advantage of the flexible union session format to literally unite the scientific community with those developing and deploying early warning systems, thereby supporting the AGU vision by supporting 'discovery, innovation and action' for the 'benefit of people and the planet'. We would like to maintain our sessions prior grouping by hazard type, with a mix of invited and non-invited talks, as well as associated poster sessions, but add in invited presentations from a diverse set of early warning experts. These experts can discuss opportunities, successes and limitations, fostering a dialog leading to improved climate science. We would seek participation from a diverse set of participants, including presenters from Africa, central Asia, and Latin America.

--- Abstract

According to the latest data from the Aon/Benfield reinsurance company, 2020 brought an estimated $258 billion dollars (USD) in global weather-related economic losses. Tropical cyclones resulted in $78 billion in losses globally, and the Atlantic hurricane season was the busiest on record. Cyclone Amphan battered India and Bangladesh while two landfalling typhoons struck the Philippines, with Typhoon Goni being the strongest on record, with wind speeds of 315 kilometers per hour. Flooding events resulted in another $76 billion in losses, as extreme monsoon rains in India claimed almost 2,000 lives. Severe weather, wildfire, and drought together brought another $93 billion in loss. Understanding, anticipating, and responding to these types of climate extremes demands rapid improvements in climate science. This session brings together both climate scientists and early warning practitioners to share discoveries and descriptions from the frontlines of innovation and real-world early warning and early action. The session’s overall objective is to foster a more inclusive and diverse dialogue that bridges the gap between research and application.

Extreme events associated with extreme temperatures, droughts, floods, and wildfires represent the greatest impacts of climate variability on our environment and society. In the ocean, marine heat waves can be extremely damaging to marine ecosystems, coral reefs, and fisheries. Understanding and predicting these types of extreme events is critical for effective decision-making, mitigation, and adaptation. However, this understanding and predictive capacity presents significant scientific challenges due to gaps in our understanding, limitations in models and modeling approaches, and lack of observations. This session invites contributions that advance our understanding of extremes from weather to climate timescales and/or their impacts, including theoretical research, data analysis, numerical modeling, and/or data-model integration. This session also welcomes studies in relevant areas such as weather dynamics, maritime hazards, impacts of climate variability and change on water cycle extremes, surface/subsurface water interactions, managed and unmanaged ecosystems, and environmental and societal impacts of extreme events. Finally, this session also welcomes presentations from early warning/early action practitioners who like to share their success and/or communicate gaps and hurdles they face.

• AMS: American Meteorological Society -