Each year from January to June, hundreds of scientists from around the world crunch the numbers on the previous year's climate, reviewing and cataloging everything from sea level, to the number and strength of hurricanes in every part of the ocean, to the size of the Arctic sea ice pack.
Led by scientists from NOAA’s National Centers for Environmental Information and published by the Bulletin of the American Meteorology Society, this year's report (full download) offers insight on global climate indicators, extreme weather events, and other valuable information on the state of the climate.
Surface Temperature in 2018
The year 2018 was the fourth warmest year on record, despite La Niña conditions (colder-than-average ocean temperatures in the Pacific Ocean) early in the year and the lack of a short-term warming El Niño influence until late in the year. The global land-only surface temperature for 2018 was 1.12°C (2.02°F) above the 20th-century average. The report found that the major indicators of climate change continued to reflect trends consistent with a warming planet.
Ten Warmest Years (1880–2018)
The table above lists the global combined land and ocean annually-averaged temperature rank and anomaly for each of the 10 warmest years on record.
Global Temperature 1900-2018
The graph above provides a longer-term temperature perspective for the globe, including both ocean and land temperatures, from four different data sets.
Sea Level Change (1993-2018)
Change in ocean water levels from 1993-2018, based on satellite altimeter data provided by Philip Thompson, University of Hawaii. On average, the global ocean has risen just over 3 inches since 1993. Global sea level is rising at an average rate of 1.2 inches (3.1 cm) per decade.
Sea Level Change (1880-2018)
For a longer-term perspective on Sea Level rise, we can see in the graph above that it has been rising for over 100 years, with a slight increase in the rate during the past few decades. The graph is from a climate.gov article published in 2018.
Carbon Dioxide Over Time (1980-2018)
Greenhouse gases were highest on record. The major greenhouse gas concentrations, including carbon dioxide (CO2), methane, and nitrous oxide, rose to new record high values during 2018. The global annual average atmospheric CO2 concentration was 407.4 parts per million (ppm). This was 2.4 ppm greater than 2017 amounts and was the highest in the modern 60-year measurement record and in ice core records dating back as far as 800,000 years.
Global Precipitation in 2018
The Global Percent of Normal Precipitation map above shows that there was no global trend in precipitation, with some regions reporting wetter conditions for the year, while many stations were dry.
Global Precipitation in 1980-2018
A longer-term perspective of global precipitation shows a slight upward trend. For 2018, some analyses showed that the year was about average, while other analyses showed well-above-average precipitation. Even with modern satellite, radar, weather station, and forecast models, measuring weather variables is still difficult!
In terms of the 2018-2019 winter season (December - February) was the wettest on record for the contiguous United States. Read more.
Glacier Activity & Snow Cover in 2018
Preliminary data indicate that glaciers around the world continued to lose mass for the 30th consecutive year. For the 25 reporting glaciers, only one reported a positive mass balance for the year. Since 1980, the cumulative loss is the equivalent of slicing 24 meters off the top of the average glacier.
In contrast, snow cover over North America and Eurasia in 2018 was above average in both spring and autumn, but it is still trending overall toward below-average extent during May and June when snowmelt is most prevalent.
Global Fire Activity in 2018
For 2018, global fire activity was the lowest on record. Globally, the levels of fire activity during 2018 were the lowest since the start of the record in 1997, with a combined burned area of about 1.2 billion acres (500 million hectares). Regionally, South America and the Northern Hemisphere of Africa each experienced their lowest annual fire activities, while North America and Australia had fire emissions that were higher than normal.