COLUMBUS (WCMH) — In the past quarter-century, the seas warmed at twice the rate of previous decades; five of the past six years were the warmest on record globally.
The first three months of 2020 continued the trend of record warmth in the Pacific, Atlantic and Indian Oceans. The Gulf of Mexico is averaging about 3 degrees warmer than normal, which has contributed to the warmest year on record so far in Florida.
Miami has endured 11 days of 90-degree heat through April 24. The maximum temperature of 97 degrees on Apr. 20 and minimum of 82 degrees on Apr. 24 are April heat records, coupled with sweltering humidity, all coming on the heels of drought conditions dating back to last year.
The atmosphere has been warming, too. The World Meteorological Organization’s Statement of Global Climate in 2019, citing data from agencies including NOAA and NASA, reported that last year was the second warmest on record, after 2016. The last five years (2014-2019) were the warmest on record, as was the most recent decade (2010-2019).
Levels of atmospheric carbon dioxide, methane and nitrous oxide reached record highs in 2019–greenhouse gases that trap Earth’s outgoing heat.
Warming impacts affect ecosystems and fish populations by bleaching corals and shifting marine habitats, which cascades to food supplies that provide nutrition for hundreds of millions of people around the world. Coral bleaching linked to record high levels of carbon dioxide threatens many marine ecosystems, where millions of fish thrive.
Corals (tiny polyps) draw in algae, converting sunlight into food. The 1,500-mile Great Barrier Reef showed marked bleaching in Australia in 2016 and 2017, and again this year. Temperatures in February were a record 5 degrees Fahrenheit above normal in the Southern Hemisphere.
The Great Barrier Reef lost about 30 percent of its corals in 2016, after a period or more normal seawater conditions from 2002 to 2016. This was the fifth bleaching since 1998. In recent years, a number of coral reef species have undergone die-offs around the world.
The oceans absorb 93 percent of the trapped heat from greenhouse gases emitted by the burning of fossil fuels. The rate of warming of the oceans has increased 40 percent since estimates were published 6 years ago.
Warm water pools cyclically in the eastern tropical Pacific during El Nino, which peaked during the winter of 2018-19. Diminished mixing and upwelling of colder nutrient-rich water during El Nino affects fisheries off the coast of South America.
Extreme weather attributed to a global warming trend was responsible for historic drought conditions that resulted in record wildfire extent in the Amazon and Australia in the warmer months in 2019. Excessive rains in East Africa from October to December, coupled with tropical cyclones in the Horn of Africa, caused widespread and deadly flooding.
The Indian Ocean Dipole acts as an Indian El Nino, which was especially strong. The climate system swings between warmer and cooler phases. Higher temperatures correlate with upward-moving air conduce to thunderstorms, which sinks and dries out farther east over Australia.
Several thousand sensors (Argo floats) routinely measure the temperature in the upper 6,500 feet of a column of water, providing a more accurate accounting of the amount of heat in the ocean.
Warmer water affects the global average sea level. Melting glaciers that reside on the edge of warmer water in Greenland and Antarctica release large quantities of meltwater. Warming oceans are also subject to thermal expansion. The global mean sea level has risen 3.4 inches since the 1980s, threatening low-lying coastal zones, which are also more susceptible to storm surges and battering wave action.
Previous marine heat waves, in the North Atlantic in 2012, and the appearance of “the blob” of warm water off the West Coast of North America in 2014, resulted in the loss of thousands of seabirds and sea lions that likely suffered from a combination of starvation and acid poisoning.
A glimmer of good news in the report is that the carbon dioxide level has plateaued (2014-2019), rising 0.6 percent in 2019, as the use of coal for electric power declined, and energy-efficiency regulations were implemented.
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