Mitigate Climate Change - Temperature - Ocean Central
Rising ocean temperatures are a direct consequence of human-driven climate change, fueled by increased greenhouse gas emissions.
As the atmosphere warms, the ocean absorbs the excess heat in the climate system, helping regulate global temperatures but at a cost to its own health. Warmer waters disrupt marine ecosystems by driving coral bleaching, forcing species migration toward cooler regions, and altering primary productivity, which underpins the marine food web.
These changes affect biodiversity, fisheries, and coastal economies, and as temperatures continue to climb, the ocean’s ability to buffer climate change weakens, creating feedback loops that accelerate global warming threaten to weaken the ocean’s ability to buffer the planet against further change.
Key Stats
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>90%
Excess heat from climate change absorbed by the ocean.
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0.88°C
Source: NASA - https://data.giss.nasa.gov/gistemp/Increase in global average sea surface temperature since 1880.
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649,475
Number of recorded marine heatwaves per year.
NASA Goddard Institute for Space Studies (GISS) (2021) GISTEMP Surface Temperature Analysis (v4). Available at: https://data.giss.nasa.gov/gistemp/
(Accessed: 24 July 2025).
Globally, the mean sea surface temperature has increased 0.88°C since 1880.
Take Urgent Action to Combat Climate Change
A global goal to reduce greenhouse gas emissions, strengthen resilience, and protect communities from the impacts of a warming planet.
Reduce Human-induced Climate Impacts to Safeguard Biodiversity
The Kunming-Montreal Global Biodiversity Framework urges a commitment to limit climate-related pressures on ecosystems to help preserve species and maintain healthy, functioning biodiversity.
Keep Global Warming Below 1.5ËšCelsius
Earth's surface is warming rapidly, with some regions, such as the Arctic, experiencing even faster rates of change. To safeguard marine ecosystems, the Paris Agreement set a goal of keeping global warming below 1.5°–2° Celsius above pre-industrial levels.
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Temporal Coverage
The number of years of available data.
145Years
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Data Frequency
Sufficient - At least 2 data points available for trend analysis AND at least one data point in the last 7 yearsInsufficient – Does not have any data at all for analysis Expired – Does not have any data in the last 10 years Not Recent – At least one data point in the last 8 to 10 years Recent – At least one data point in the last 7 years Sufficient – At least 2 data points available for trend analysis AND at least one data point in the last 7 years
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Geographic Range
100% of global data availableThe percentage of the ocean represented by the available data.
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Goal Assessment
2025 Goal - Medium Quality (Specific)None – No Global Goal Established Low – The goal is broad Medium – The goal is specific High – The goal is measurable
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2030 Goal – Low Quality (Broad)
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2050 Goal – High Quality (Measurable)
There is still so much we do not know about our oceans.
Join us in filling critical gaps in ocean data.
The ocean’s vast heat capacity has long buffered the planet from climate change, but that protective barrier is being tested.
Rising sea surface temperatures alter chemical balance, fueling acidification and deoxygenation, and trigger widespread stress in marine life. Coral bleaching, mass die-offs, and species migration now occur more frequently and at lower thresholds than climate models once predicted.
There are concerns ecosystems are moving toward changes that could have significant impacts on food security, coastal protection, and global climate stability. The global warming goal in the Paris Agreement is critical for preserving marine life as well as safeguarding the ocean’s role as Earth’s largest carbon sink and climate regulator. The loss of these functions would have significant socio-economic consequences.
Marine heatwaves, sometimes referred to as “wildfires of the ocean,” are a prolonged period of unusually high ocean temperatures that lasts days to months. These extreme warming events can cause widespread stress to marine life, leading to coral bleaching, shifts in species distributions, reduced productivity, and increased mortality, disrupting entire ecosystems.
Zhao, Qianshuo (2020), “Where Marine Protected Areas would best represent 30% of ocean biodiversity”, Mendeley Data, V1, doi:10.17632/wk6s7kh48m.1
National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (n.d.) Daily Global 5km Satellite Marine Heatwave Watch (MHW) product. NOAA Coral Reef Watch. Available at: https://coralreefwatch.noaa.gov/product/marine_heatwave/ (Accessed: 24 July 2025).
Critical Marine Areas – Marine regions that are identified as having high ecological value and conservation importance—typically because they encompass a large proportion of marine biodiversity, key habitats, or unique ecosystems—and are prioritized for protection and management to support long-term conservation goals.
CMA Area Impacted (%) – the share of Critical Marine Area surface affected by marine heatwaves.
Globally, 6.5% of critical marine areas (CMAs) are impacted by marine heatwaves in 2024.
| Most Impacted Marine Areas | CMA Area Impacted (%) |
|---|---|
| Alboran Sea | 93.105 |
| Irish Sea and St. George's Channel | 90.342 |
| Inner Seas off the West Coast of Scotland | 89.223 |
| Sea of Azov | 82.804 |
| Sea of Marmara | 80.124 |
| Rio de La Plata | 76.276 |
| Bristol Channel | 72.458 |
| Mediterranean Sea - Western Basin | 67.52 |
| Ionian Sea | 66.602 |
| Bay of Biscay | 64.579 |
| Caribbean Sea | 64.32 |
| Adriatic Sea | 58.403 |
| Gulf of Mexico | 56.949 |
| Red Sea | 54.907 |
| Tyrrhenian Sea | 47.73 |
| Mediterranean Sea - Eastern Basin | 46.25 |
| Strait of Gibraltar | 45.58 |
| English Channel | 43.959 |
| Balearic (Iberian Sea) | 41.563 |
| Gulf of St. Lawrence | 40.58 |
| Arabian Sea | 39.52 |
| Japan Sea | 38.207 |
| North Atlantic Ocean | 37.706 |
| North Sea | 36.729 |
| Laccadive Sea | 36.368 |
| Aegean Sea | 32.03 |
| Barentsz Sea | 29.242 |
| Tasman Sea | 28.82 |
| Mozambique Channel | 28.503 |
| Celtic Sea | 27.632 |
| Hudson Bay | 26.083 |
| South China Sea | 25.763 |
| The Coastal Waters of Southeast Alaska and British Columbia | 25.578 |
| Malacca Strait | 23.908 |
| South Atlantic Ocean | 22.858 |
| Sea of Okhotsk | 22.719 |
| Yellow Sea | 22.502 |
| Indian Ocean | 22.351 |
| Eastern China Sea | 19.146 |
| Black Sea | 19 |
| Java Sea | 18.859 |
| Labrador Sea | 18.854 |
| Bass Strait | 18.778 |
| Gulf of California | 16.553 |
| Singapore Strait | 16.471 |
| North Pacific Ocean | 16.368 |
| Celebes Sea | 15.43 |
| Gulf of Boni | 15.422 |
| Sulu Sea | 14.914 |
| Greenland Sea | 14.176 |
| Seto Naikai or Inland Sea | 12.884 |
| Gulf of Aqaba | 12.657 |
| Ligurian Sea | 12.537 |
| South Pacific Ocean | 12.438 |
| Andaman or Burma Sea | 12.226 |
| Gulf of Aden | 11.944 |
| Gulf of Suez | 10.836 |
| Bay of Bengal | 9.2446 |
| Norwegian Sea | 8.8326 |
| White Sea | 8.5193 |
| Bering Sea | 8.0107 |
| Gulf of Thailand | 7.913 |
| Coral Sea | 7.273 |
| Kara Sea | 7.1756 |
| Makassar Strait | 7.0255 |
| Philippine Sea | 7.0232 |
| Bay of Fundy | 6.1319 |
| Gulf of Bothnia | 4.7193 |
| Gulf of Guinea | 4.4058 |
| Chukchi Sea | 4.1747 |
| Great Australian Bight | 3.7631 |
| Davis Strait | 3.6382 |
| Baltic Sea | 3.1499 |
| Ceram Sea | 3.1467 |
| Skagerrak | 2.8478 |
| Southern Ocean | 1.3616 |
| Timor Sea | 1.3384 |
| Hudson Strait | 1.0044 |
| Molukka Sea | 0.94172 |
| Persian Gulf | 0.78524 |
| Gulf of Tomini | 0.54916 |
| Arafura Sea | 0.54727 |
| Gulf of Oman | 0.53482 |
| Solomon Sea | 0.21086 |
| Laptev Sea | 0.12251 |
| Gulf of Alaska | 0.11887 |
| Banda Sea | 0.10334 |
| The Northwestern Passages | 0.098401 |
| Kattegat | 0.050117 |
| East Siberian Sea | 0.0016417 |
| Savu Sea | 0 |
| Bali Sea | 0 |
| Flores Sea | 0 |
| Bismarck Sea | 0 |
| Beaufort Sea | 0 |
| Baffin Bay | 0 |
| Lincoln Sea | 0 |
| Gulf of Riga | 0 |
| Gulf of Finland | 0 |
| Halmahera Sea | 0 |
| Arctic Ocean | 0 |
Rising greenhouse gas emissions trap more heat in the atmosphere, causing ocean temperatures to increase. This warming stresses marine ecosystems by disrupting habitats, altering species distributions, and triggering events like coral bleaching.
Lan, X., P. Tans, & K.W. Thoning (2025). Trends in globally-averaged COâ‚‚ determined from NOAA Global Monitoring Laboratory measurements (Version 2025-11) NOAA Global Monitoring Laboratory. https://doi.org/10.15138/9N0H-ZH07.
NASA Goddard Institute for Space Studies (GISS) (2021) GISTEMP Surface Temperature Analysis (v4). Available at: https://data.giss.nasa.gov/gistemp/
(Accessed: 24 July 2025).
Ritchie, H., Roser, M. and Rosado, P. (2024) COâ‚‚ and greenhouse gas emissions. Our World in Data. Available at: https://ourworldindata.org/co2-and-greenhouse-gas-emissions (Accessed: 13 January 2026).
Globally, the 100 ppm increase in COâ‚‚ concentration has coincided with a 1.2ËšC increase in global mean surface temperature from 1959 to 2024.
Rising temperatures cause coral to become stressed and expel the algae they rely on—a process called coral bleaching—which weakens the coral and increases its risk of disease and death.
Hughes, T. P., et al. (2018). Spatial and temporal patterns of mass bleaching of corals in the Anthropocene. Science. – processed by Our World in Data. https://ourworldindata.org/grapher/coral-bleaching-events
There were 43 severe coral bleaching events in 2016.
Tackling rising marine temperatures demands urgent action on both mitigation and adaptation to safeguard ocean health and the biodiversity it supports.
Taking Action
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Scale Up Blue Carbon Solutions
Protect and restore coastal ecosystems, including mangroves, seagrasses, and salt marshes, that naturally capture and store carbon. These blue carbon systems strengthen biodiversity, buffer coasts from storms, and play a vital role in reducing atmospheric COâ‚‚.
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Restore Marine Ecosystems
Rebuild coral reefs, fisheries, and megafauna populations to enhance ocean resilience against climate change impacts. Natural and artificial reef restoration supports biodiversity, reduces erosion, and protects coastal infrastructure.
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 Expand Offshore Renewable Energy
Accelerate wind, tidal, and wave energy projects to cut reliance on fossil fuels and drive the decarbonization of the global energy mix, while creating new ocean-based jobs.
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Decarbonize the Ocean Economy
Reduce emissions across shipping, fisheries, and tourism through cleaner fuels, efficiency standards, and low-carbon technologies, easing climate pressure on marine systems.
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Build Coastal Resilience
Combine engineered defenses with nature-based solutions, such as mangrove and reef restoration, to protect coastal communities from storms and sea-level rise. Innovative tools, including ecosystem insurance, can further strengthen adaptation.
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Strengthen Climate Adaptation in Maritime Industries
Modernize ports, fleets, and logistics to withstand climate risks. Invest in early warning systems, resilient infrastructure, and real-time monitoring to safeguard supply chains and maritime operations.
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 Rebuild Fisheries and Protect Marine Life
Restore fish stocks and marine megafauna to boost biodiversity and carbon sequestration. Use AI and advanced tracking to target fishing sustainably, cut bycatch, and protect vulnerable species.
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 Enhance Ocean-Climate Monitoring & Early Warning Systems
Establish and expand real-time global observing networks for ocean temperature, salinity, ice cover, circulation and heat uptake. Use this data to model tipping points, inform policy, and trigger rapid response.
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Mobilize Climate Finance for Ocean Resilience
Channel investment into blue carbon, ocean-based carbon removal, coastal protection, and climate-resilient maritime infrastructure. Align public and private finance with ocean-climate goals, and integrate ocean health into carbon accounting and national climate strategies.
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View relevant data layers on the globe using the available map toggle in the top right of each card in the left panel.
View relevant data layers on the globe using the available map toggle in the top right of each card in the left panel.