COLUMBUS, OH (WCMH)– A record-tying hot summer in the Northern Hemisphere and blazing heat in Australia in December capped off the second hottest year globally, according to the U.S. National Oceanic and Atmospheric Administration and NASA.
2019 was the warmest year on record (58.7 degrees Fahrenheit), 1.71 degrees above the 20th century average for ocean buoys and land surfaces, according to NOAA. Last year fell just shy of the 2016 record warmest departure from normal by 0.07 degree, according to NOAA’s measurements.
June 2019 was the warmest June, and July equaled the warmest month. The five warmest years have occurred since 2015 (2016 was the warmest).
NASA data, which applies slightly different methodologies, showed similar results. The global mean global temperature in 2019 was 1.77 degrees above 30-year mid-20th century mean (1951-80), just shy of 2016 (1.83 degrees).
The past five years are the warmest on record globally, and eight of the 10 warmest years occurred in the past decade. (The remaining top 10 hottest years worldwide happened in 2005 and 1998.)
Temperatures worldwide have warmed nearly 2 degrees Fahrenheit since the 1880s. Much of the warming has occurred in the past half-century, and the most recent decade was the warmest, beating out 2000-2009 by 0.3 degree.
Prolonged drought, extreme heat, and longer wildfire seasons took a human and wildlife toll, which was highlighted by the historic extent of the Australian bushfires (15.6 million acres). In other parts of the world, warmer seas and air temperatures contribute to more evaporation and heavier rain events, resulting in flash flooding.
Arctic sea ice continues to melt at a rapid pace during the warmer months, reaching its second-lowest extent (about 3.94 square miles) in the satellite record since 1978 (tied with 2016 and 2007). The Arctic has warmed slightly more than three times faster than the rest of the world. Alaska baked in its warmest year on record (32.2 degrees Fahrenheit), 6.2 degrees above the long-term average (1925-2000), according to NOAA scientists.
Antarctic sea ice also reached its second-lowest coverage (4.16 million square miles) in 2019.
The steady loss of tropical high-elevation glacial mass requires experts to work faster to secure historical data, as glaciers slowly retreat. Lonnie Thompson, a geologist in the Ohio State University School of Earth Sciences, has completed 80 expeditions to retrieve ice from mountain glaciers that reveal a record of Earth’s climate as far back as 800,000 years.
Ice cores are stored at the Byrd Polar and Climate Research Center for further analysis of the chemical isotopes trapped in ancient air bubbles. Temperature and precipitation patterns are inferred by the deposition of pollen, dust and volcanic ash.
“We look at microbes, bacteria, viruses; everything gets archived in the ice,” Thompson said.
The team of researchers encountered harsh conditions ascending a mountain peak to drill at an elevation of 20,000 feet in July 2019. The observed increasing melt rate contributes to higher sea levels.
Mountaintop glaciers are smaller and more susceptible to melting, said Thompson. Warmer conditions raise the snow level, and rain falls at altitudes where mostly snow had accumulated and restocked the ice. When water replaces ice, more heat is absorbed from the sun, accelerating the melt cycle. Water also gets in the crevasses and causes the glacier to slide to a slightly lower and warmer elevation, Thompson noted.
A very warm start to January 2020 (more than 10 degrees above normal through Jan. 18) left Lake Erie ice-free at a record late date.
Ohio had its warmest decade (2010-19) dating back to the early 1900s. Total precipitation and heavy rain events have increased in Ohio and much of the eastern half of the U.S.
Most of the Great Lakes achieved record high water levels in July and August 2019, and some basins had the greatest rises in history since 1918. Eroding shorelines and impacted recreational activities and imperiled homes and cottages, with several collapsing into the water in the past year.
Heavy rainfall and runoff, coupled with less evaporation, causes lake levels to rise. The 12 months spanning the latter half of 2018 and the first half of 2019 combined for the wettest year-long period in more than a century of record-keeping.
“This is by far the highest water levels we’ve seen,” said Kristen Fussell, assistant director of administration and research Ohio Sea Grant College Program, who grew up in the Toledo area and keeps a close eye on lake levels algal blooms.
“More frequent and heavy rain events leading to high water levels in the Great Lakes,” she said are responsible for recent fluctuations.
More than 1.5 million acres of corn and soybeans that are usually planted lay fallow due to excessive rainfall that left fields partly submerged through most of June in northwestern Ohio.
The U.S. Department of Agriculture reported that were unable to plant more than 19.4 million acres of their primary crops — the most since the USDA’s Farm Service Agency began keeping records in 2007.
Failing sewage systems and septic tanks during heavy rain events, coupled with increased agricultural runoff that contains nitrates, contributes to large blooms of toxic algae when sunlight heat the water more intensely in the summertime.
Atmospheric carbon dioxide reached another record high in 2019 of 414.7 parts per million (ppm), based on NOAA data taken at Mauna Loa Atmospheric Baseline Observatory. Rising greenhouse gas levels (carbon dioxide, methane, nitrous oxide, primarily) produced by human activities are strongly linked to higher temperatures, because those gases preferentially trap outgoing heat from Earth.
The combination of heat and extreme drought, which is more likely in a warmer world, fueled devastating wildfires in the western U.S. and Australia. Blazes that raged in California and Alaska in 2019 resulted in more than $1 billion in damages.
In 2019, NOAA recorded 14 billion-dollar natural disasters in the U.S. (flooding, violent storms, wildfires, tropical cyclones) that caused an estimated $45 billion in economic losses and 44 deaths. Wildfires were responsible for $4.5 million in damages to property, concentrated in Alaska and California. Major flooding ($20 billion) and severe storms (nearly $14 billion) also took a heavy toll.