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Coral Bleaching Increase

The rate and magnitude of climate disruption on coral reefs is already testing the ability of organisms to adapt, leading to increased risk of extinction, biodiversity loss, and the compromising of ecosystem services. Ecosystems depend upon biodiversity to be healthy and to ensure protection against disruption and disaster. As ocean temperature increases, only the most resilient species, are able to thrive in a warmer climate.

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About 93 percent of the heat trapped by greenhouse gas emissions since the 1970s has made its way into the oceans.[1] Increased sea surface temperature makes mass coral bleaching events more frequent and severe. When sea surface temperatures rise above average (typically by 1.0–1.5°C above seasonal maximum mean temperatures) in reefs that receive a relatively high amount of light, the algae start producing toxic compounds, prompting the corals to expel them and turn white.[2][3]

Once bleached, the corals are physiologically damaged and more susceptible to disease.[4][5] Widespread bleaching becomes likely when corals are exposed to more than four accumulated weeks of heat stress and excessive sunlight.[3][6]

It is possible for corals to recover,[7] but if water temperatures take too long to return to normal, the organisms actually starve and die.[7][8] Significant bleaching or death is possible after eight accumulated weeks of heat stress.[6]

Global trends

In the last three decades, 19 percent of global coral reef area has been lost due to coral bleaching.[8] Global-scale bleaching events were not observed until 1998.[9]

Global warming triggered the Earth’s third global coral bleaching event, which began in the north Pacific in the summer of 2014 and became global in 2015. The fingerprint of global warming was found in this event.[10]

There is indisputable evidence climate change is harming the Great Barrier Reef. Climate change has increased sea surface temperatures in the hottest March months by just over 1°C.[11]

Abnormally warm ocean temperatures linked to anthropogenic greenhouse gas emissions may have increased the probability of occurrence of thermal stress events like the 2005 eastern Caribbean coral bleaching event by an order of magnitude.[12]

The two earlier global coral bleaching events on record lasted only one year each.[13] They were observed in 1998 and 2010, meaning all such events have taken place within the last 20 years.

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Air Mass Temperature Increase
Arctic Amplification
Extreme Heat and Heat Waves
Glacier and Ice Sheet Melt
Global Warming
Greenhouse Gas Emissions
Land Ice and Snow Cover Decline
Land Surface Temperature Increase
Permafrost Thaw
Precipitation Falls as Rain Instead of Snow
Sea Ice Decline
Sea Surface Temperature Increase
Season Creep/ Phenology Change
Snowpack Decline
Snowpack Melting Earlier and/or Faster
Atmospheric Moisture Increase
Extreme Precipitation Increase
Runoff and Flood Risk Increase
Total Precipitation Increase
Atmospheric Blocking Increase
Atmospheric River Change
Extreme El Niño Frequency Increase
Gulf Stream System Weakening
Hadley Cell Expansion
Large Scale Global Circulation Change/ Dynamical Changes
North Atlantic Surface Temperature Decrease
Ocean Acidification Increase
Southwestern US Precipitation Decrease
Surface Ozone Change
Surface Wind Speed Change
Drought Risk Increase
Land Surface Drying Increase
Intense Atlantic Hurricane Frequency Increase
Intense Cyclone, Hurricane, Typhoon Frequency Increase
Intense Northwest Pacific Typhoon Frequency Increase
Tropical Cyclone Steering Change
Wildfire Risk Increase
Coastal Flooding Increase
Sea Level Rise
Air Mass Temperature Increase
Storm Surge Increase
Thermal Expansion of the Ocean
Winter Storm Risk Increase
Coral Bleaching Increase
Habitat Shift or Decline
Parasite, Bacteria and Virus Population Increase
Pine Beetle Outbreaks
Heat-Related Illness Increase
Infectious Gastrointestinal Disease Risk Increase
Respiratory Disease Risk Increase
Vector-Borne Disease Risk Increase
Storm Intensity Increase
Tornado Risk Increase
Wind Damage Risk Increase
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