2021's climate extremes show global warming has 'no sign of slowing'

A new federal summary of the globe's climate last year takes bits and pieces of grim news from the past 18 months and rolls it into a sobering report on the world's warming climate. 

Long-term warming trends continue worldwide, even when interrupted by temporary cooler weather phenomena, such as the lingering La Nina in the Pacific, concluded the 2021 "State of the Climate" report released Wednesday.

"The data presented in this report are clear – we continue to see more compelling scientific evidence that climate change has global impacts and shows no sign of slowing,” said Rick Spinrad, administrator of the National Oceanic and Atmospheric Administration. The report is prepared by NOAA's National Centers for Environmental Information, with contributions from scientists around the world.

Given the floods, drought and historic heat that have continued this year, Spinrad said the "climate crisis is not a future threat but something we must address today."

He and Paul Higgins, associate director of the American Meteorological Society, said the world should use the report to become more resilient against climate extremes. 

A cyclist bikes past the setting sun at Papago Park during a heat wave where temperatures hit 115 degrees on June 15, 2021, in Phoenix.

"If we take it seriously and use it wisely, it can help us thrive on a planet that is increasingly small in comparison to the impact of our activities," Higgins said.

The news, however, wasn't all bad. The La Nina lowered sea surface temperatures in the Pacific and helped suppress other global temperatures. Also, the South Pole saw its coldest winter on record, despite warmer temperatures elsewhere in Antarctica.  

Here are some of the report's biggest takeaways:

Global average temperatures and sea levels keep rising

The Earth's warming trend continued, and for the 10th consecutive year, the global mean sea level set a record high.

  • Scientific analyses showed global surface temperatures were about .5 degrees above the 1991-2020 average.
  • The last seven years have been the warmest since recordkeeping began in the mid- to late-1800s, according to the meteorological society. 
  • Sea levels were 3.8 inches above the 1993 average, a two-tenths of an inch increase over 2020.  Federal scientists say every inch of sea level rise increases the risk of high tide flooding days in cities along the Atlantic and Gulf coasts. 

Is the globe prepared? Extreme heat waves may be our new normal, thanks to climate change.

Some nations saw dramatic impacts 

Temperature extremes set many new record highs, but also a few record lows. 

  • China and New Zealand saw their warmest years on record.
  • In Kyoto, Japan, one of its native cherry tree species' full bloom dates were the earliest on record, dating back to 801. 
  • Europe saw its second-hottest summer on record, setting a new high temperature of 119.8 degrees in Sicily on Aug. 11, 2021. 
  • Spain set a new record low in January, when the temperature at Clot del Tuc de la Llança in the Pyrenees dropped to minus 29.4 degrees. 

Learn more about earlier bloom dates:Festivals forced to adapt as climate change disrupts historic weather patterns

Polar regions suffered 

Glaciers around the world continued melting for the 34th year in a row, while the temperature of permafrost in many areas reached record high levels. 

  • in June 2021, Canada's Northwest Territories set an all-time high of 103.8 degrees, the highest temperature ever recorded north of the 60th parallel. 
  • A station on the Greenland Ice Sheet recorded the first rainfall since recordkeeping began 33 years ago. It used to be too cold at the top of the ice sheet for it to rain. Scientists say warming conditions there are melting more of the ice sheet, adding to higher sea levels. 

Weather extremes reigned 

Some areas experienced new levels of drought, while others saw record rainfall. Experts say both reflect the warming climate. 

  • Nearly a third of the world's land areas saw drought conditions in August 2021, a record high. 
  • East Africa saw the lowest-ever rainfall along the equator, the third failed rainy season in a row, threatening food security for more than 20 million people. 
  • In Zhengzhou, China, 7.9 inches of rain fell in a single hour on July 20, the highest one-hour rainfall ever reported for the mainland. Scientists say warmer air holds more water and contributes to extreme rainfall.
  • In October in Rossiglione, Italy, 29.2 inches of rain fell in just 12 hours, a European record. 

USA TODAY investigates:How a summer of extreme weather reveals a stunning shift in the way rain falls in America.

Greenhouse gas emissions kept climbing

The big two greenhouse gases  – carbon dioxide and methane – rose to new record highs. Climate scientists say reducing emissions is critical to prevent further warming. 

  • Carbon dioxide reached an average annual concentration of 414.7 parts per million, up 2.6 parts per million over 2020. That's the fifth-highest growth rate since monitoring began in 1958.
  • Methane continued its upward trend upward with an increase of 18 parts per billion, the biggest increase since measurements began.
  • Nitrous oxide also hit 334.3 parts per billion, the third highest level since 2001.

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Dinah Voyles Pulver covers climate and environmental issues for USA TODAY. She can be reached at dpulver@gannett.com or at @dinahvp on Twitter.