Night falls on the Qolqepunku glacier on May 28, 2018, in Ocongate, Peru. A study by the Peruvian government found that its country's glaciers had shrunk by more than 20% over a 30-year period.

(Dan Kitwood/Getty Images)

At a Glance

The combined global warming power of greenhouse gases increased nearly 43% from 1990 to 2018.2018 was the fourth-warmest year on record.The global average sea level reached a record high in 2018 and was about 3.2 inches higher than in 1993.

The dominant greenhouse gases that cause global warming reached record highs last year, according to a report by the American Meteorological Society.

The combined global warming power of carbon dioxide, methane and nitrous oxide, along with a few other gases, has increased by nearly 43% since 1990, according to the study.

Global carbon dioxide concentrations rose to a record level last year: 407.4 parts per million. That concentration, an increase of 2.4 ppm over 2017, is "the highest in the modern atmospheric measurement record and in ice core records dating back as far as 800,000 years," the report said.

Methane concentrations were 1858.5 parts per billion, up 8.9 ppb over 2017. Nitrous oxide was 330.9 ppb, an increase of 1.1 ppb from the previous year.

The annual report, based on contributions from 475 scientists from 57 countries, found that the major indicators of climate change continued "to ," according to a news release.

"This is yet another in a series of expert, science-based reports that continue to ," Dr. Marshall Shepherd, a professor of Geography and Atmospheric Sciences at the University of Georgia, told CNN.com.

"The findings from their State of the Climate report rises above some blog or opinion on social media," said Shepherd, who is also a former president of the American Meteorological Society. "Through the process of science, they are sounding an alarm about the 'here-and-now' climate crises."

Temperatures

The study said 2018 was the fourth-warmest year on record since records began in the mid-to-late 1800s. Only 2015, 2016 and 2017 were warmer.

People cool off in a fountain at Washington Square Park in New York's West Village on Aug. 28, 2018. A late-summer heat wave gripped New York and much of the East Coast with temperatures in the 90s and a heat index making it feel more like 100 degrees.

(Spencer Platt/Getty Images)

Europe observed its second-warmest year since at least 1950, behind only 2014. Several countries, including France, Italy, Serbia, Croatia, Greece, and Bosnia and Herzegovina, reported record-high annual temperatures.

The temperature in the Arctic was the third-highest since 1900, trailing only 2016 and 2017. The maximum extent of sea ice was the second-lowest in the 38 years records have been kept, and first-year ice dominates the ice cover. Greenland was the exception. Regional summer temperatures were generally below or near average, and glaciers there added ice for the first time since 1999 (a recent heat wave has ).

In the Antarctic, 2018 was warmer than average for the continent as a whole. Summer sea ice extent was the second-lowest on record.

The world’s glaciers also lost mass for the 30th straight year. The cumulative loss since 1980 is equal to cutting 79 feet off the top of the average glacier.

The Oceans

Sea surface temperature was near-record high. The globally averaged sea surface temperature cooled slightly since setting a record in 2016, but it was still higher than the 1981–2010 mean.

Despite slight cooling on the surface, the amount of heat stored in the top 2,300 feet of the ocean reached record highs in 2018, according to five of the six datasets analyzed. Oceans absorb more than 90% of the planet's excess heat from global warming, the report said.

The ocean's surface is saltier, reinforcing evidence that dry regions are becoming drier and saltier, and wet regions rainier and fresher.

Global sea level continues to rise at an average rate of 1.2 inches every 10 years, the report said. The global average reached a record high in 2018 and it was about 3.2 inches higher than in 1993.

Hurricanes

The 95 named tropical cyclones across all ocean basins in 2018 was well above the 1981–2010 average of 82. Eleven cyclones reached Category 5 on the Saffir-Simpson scale, including Hurricane Michael, which was the fourth-strongest hurricane to make landfall in the United States in the 168 years records have been kept.