Coastal Climate Change

Earth’s climate is now changing faster than at any point in the history of modern civilization, primarily as a result of human activities. Global climate change has already resulted in a wide range of impacts across every region of the United States. Oceans are warming, rising, and becoming more acidic, and heavy precipitation events occur more often leading to increased flooding along the U.S. coastline.

Below are links to reports that provide a general overview of climate change as it affects coastal areas.

Climate Literacy Guide: Essential Principles for Understanding and Addressing Climate Change: A Guide for Educators, Communicators, and Decision-Makers
Third Edition: September 2024

Published by the U.S. Global Change Research Program, Climate Literacy is the leading climate education resource for educators in the classroom and in the field. This third edition represents the collective efforts of 15 federal agencies and the White House to share the latest understanding, impacts, and work in climate science.

State of the Global Climate 2024

The clear signs of human-induced climate change reached new heights in 2024, which was likely the first calendar year to be more than 1.5°C above the pre-industrial era, with a global mean near-surface temperature of 1.55 ± 0.13 °C above the 1850-1900 average.

This is the warmest year in the 175-year observational record. The State of the Global Climate 2024 report, prepared by the World Meteorological Organization, underlines the massive economic and social upheavals from extreme weather and the long-term impacts of record ocean heat and sea-level rise.

Featured articles explore progress towards the Paris Agreement goals and the drivers behind 2024’s record heat. Supplementary reports detail climate services and major events, including floods, droughts, tropical cyclones and wildfires, underscoring the urgent need for stronger early warning systems and investment in climate services to protect lives and livelihoods.

Key messages

Key climate change indicators again reach record levels
Long-term warming (averaged over decades) remains below 1.5°C
Sea-level rise and ocean warming irreversible for hundreds of years
Record greenhouse gas concentrations combined with El Niño and other factors to drive 2024 record heat
Early warnings and climate services are vital to protect communities and economies

The Fifth National Climate Assessment

The Fifth National Climate Assessment is the US Government’s preeminent report on climate change impacts, risks, and responses. It is a congressionally mandated interagency effort that provides the scientific foundation to support informed decision-making across the United States.

Overview
- The effects of human-caused climate change are already far-reaching and worsening across every region of the United States. Rapidly reducing greenhouse gas emissions can limit future warming and associated increases in many risks. Across the country, efforts to adapt to climate change and reduce emissions have expanded since 2018, and US emissions have fallen since peaking in 2007. However, without deeper cuts in global net greenhouse gas emissions and accelerated adaptation efforts, severe climate risks to the United States will continue to grow.
Chapter 9: Coastal Effects
- Climate impacts, including rising sea levels and shifting storm patterns, are transforming coastal landscapes and undermining the resilience of communities and ecosystems. Proactive community-led adaptation strategies, including nature-based solutions and planned relocation, can help communities adapt to both current and future increases in the severity of coastal hazards across the US.
Chapter 10: Ocean Ecosystems and Marine Resources
- Climate change is altering US marine ecosystems in unprecedented ways, leading to shifts in species’ location, productivity, and seasonal timing. This poses risks to fisheries, tourism, recreation, transportation, energy, and other economic sectors—and also undermines critical connections between people and the ocean, especially within Indigenous communities. Swift implementation of equity-focused adaptation and mitigation could help limit future risks.
Chapter 22: Southeast
- The Southeast’s growing population faces increasing threats from climate change, with impacts on human health, ecosystems, economies, infrastructure, and food systems. While there have been notable advancements in adaptation throughout the region, these efforts tend to be concentrated in wealthier coastal and metropolitan areas, leaving rural and other under-resourced communities at risk. Coordinated climate strategies could improve equity, well-being, and economic vitality.
Chapter 31: Adaptation
- Adaptation activities are occurring across the US but have been small in scale, incremental in approach, and lacking in sufficient investment. Transformative approaches will be necessary to adequately address current and future risks. To improve capacity and promote an equitable future, adaptation activities must address the uneven distribution of climate harms and incorporate collaboration with local communities.

State of the Climate in 2023

This is the 34th issuance of the annual assessment now known as State of the Climate, published in the Bulletin since 1996. As a supplement to the Bulletin, its foremost function is to document the status and trajectory of many components of the climate system. However, as a series, the report also documents the status and trajectory of our capacity and commitment to observe the climate system.

View by Chapter:

Another Year of Record Heat for the Oceans

Changes in ocean heat content (OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum. According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ (1 Zetta Joules = 10²¹ Joules); and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins (the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier—fresh gets fresher” pattern, also reached its highest level on record in 2022, implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Niña event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.

Cheng, L., Abraham, J., Trenberth, K.E. et al. Another Year of Record Heat for the Oceans. Adv. Atmos. Sci. 40, 963–974 (2023). https://doi.org/10.1007/s00376-023-2385-2

IPCC Synthesis Report of the Sixth Assessment Report

IPCC Sixth Assessment Report: Climate Change 2022: Impacts, Adaptation and Vulnerability

The Working Group II contribution to the IPCC Sixth Assessment Report assesses the impacts of climate change, looking at ecosystems, biodiversity, and human communities at global and regional levels. It also reviews vulnerabilities and the capacities and limits of the natural world and human societies to adapt to climate change.

Cross-Chapter Papers

2022 Global and Regional Sea Level Rise Scenarios for the United States: Technical Report; Sea Level Rise and Coastal Flood Hazard and Tools Interagency Task Force

The Sea Level Rise Technical Report provides the most up-to-date sea level rise projections available for all U.S. states and territories; decision-makers will look to it for information.

This multi-agency effort, representing the first update since 2017, offers projections out to the year 2150 and information to help communities assess potential changes in average tide heights and height-specific threshold frequencies as they strive to adapt to sea level rise.

There were four main takeaways from the report:

The Next 30 Years of Sea Level Rise. Sea level along the U.S. coastline is projected to rise, on average, 10 – 12 inches (0.25 – 0.30 meters) in the next 30 years (2020 – 2050), which will be as much as the rise measured over the last 100 years (1920 – 2020). Sea level rise will vary regionally along U.S. coasts because of changes in both land and ocean height.
More Damaging Flooding Projected. Sea level rise will create a profound shift in coastal flooding over the next 30 years by causing tide and storm surge heights to increase and reach further inland. By 2050, “moderate” (typically damaging) flooding is expected to occur, on average, more than 10 times as often as it does today, and can be intensified by local factors.
Emissions Matter. Current and future emissions matter. About 2 feet (0.6 meters) of sea level rise along the U.S. coastline is increasingly likely between 2020 and 2100 because of emissions to date. Failing to curb future emissions could cause an additional 1.5 – 5 feet (0.5 – 1.5 meters) of rise for a total of 3.5 – 7 feet (1.1 – 2.1 meters) by the end of this century.
Continual Tracking. Continuously tracking how and why sea level is changing is an important part of informing plans for adaptation. Our ability to monitor and understand the individual factors that contribute to sea level rise allows us to track sea level changes in a way that has never before been possible (e.g., using satellites to track global ocean levels and ice sheet thickness). Ongoing and expanded monitoring will be critical as sea levels continue to rise.

Climate Change 2021: The Physical Science Basis

The Working Group I contribution to the Sixth Assessment Report is the most up-to-date physical understanding of the climate system and climate change, bringing together the latest advances in climate science, and combining multiple lines of evidence from paleoclimate, observations, process understanding, and global and regional climate simulations.

Summary for Policymakers
- The Summary for Policymakers (SPM) provides a high-level summary of the understanding of the current state of the climate, including how it is changing and the role of human influence, and the state of knowledge about possible climate futures, climate information relevant to regions and sectors, and limiting human-induced climate change. (39 pages)
Chapter 9: Ocean, cryosphere, and sea level change
- This chapter assesses past and projected changes in the ocean, cryosphere and sea level using paleo-reconstructions, instrumental observations and model simulations. In the following summary, we update and expand the related assessments from the IPCC Fifth Assessment Report (AR5), the Special Report on Global Warming of 1.5oC (SR1.5) and the Special Report on Ocean and Cryosphere in a Changing Climate (SROCC). Major advances in this chapter since the SROCC include the synthesis of extended and new observations, which allows for improved assessment of past change, processes and budgets for the last century, and the use of a hierarchy of models and emulators, which provide improved projections and uncertainty estimates of future change. In addition, the systematic use of model emulators makes our projections of ocean heat content, land-ice loss and sea level rise fully consistent both with each other and with the assessed equilibrium climate sensitivity and projections of global surface air temperature across the entire report.
Chapter 11: Weather and climate extreme events in a changing climate
- This chapter assesses changes in weather and climate extremes on regional and global scales, including observed changes and their attribution, as well as projected changes. The extremes considered include temperature extremes, heavy precipitation and pluvial floods, river floods, droughts, storms (including tropical cyclones), as well as compound events (multivariate and concurrent extremes).

State of the Climate in 2020

This is the 31st issuance of the State of the Climate, published in the Bulletin of the American Meteorological Society since 1996. As a supplement to the Bulletin, its foremost function is to document the status and trajectory of many components of the climate system. However, as a series, the report also documents the status and trajectory of our capacity and commitment to observe the climate system.

View by Chapter: