The State of the Global Climate report is an annual publication from the World Meteorological Organization (WMO) that presents the latest findings on the state of climate change worldwide. The report combines observations from global networks of weather and climate stations, ocean buoys, and satellites, as well as modeling studies, to provide a comprehensive assessment of the Earth’s climate system. The most recent report, released ahead of Earth Day 2023, reveals several alarming trends that highlight the urgent need for climate action.
Key Findings of the Report:
- High Global Mean Temperature: In 2022, the global mean temperature was 1.15 [1.02 to 1.28] °C above the average temperature of 1850-1900. The years between 2015 and 2022 were the eight warmest years recorded since 1850. Even though there were three consecutive years of cooling La Niña, 2022 was still the 5th or 6th warmest year. This is a rare occurrence as such a “triple-dip” La Niña has only happened three times in the past 50 years.
- Concentrations of 3 Main GHGs: In 2021, the levels of the three primary greenhouse gases – carbon dioxide, methane, and nitrous oxide – reached the highest observed levels in the period between 1984 and 2021. The amount of methane concentration increased significantly from 2020 to 2021, making it the highest annual increase recorded. Presently, real-time measurements from particular locations indicate that the levels of these greenhouse gases continued to rise in 2022.
- Reference Glaciers: Glaciers around the world are melting at an alarming rate, with reference glaciers showing an average decrease in thickness of over 1.3 meters between October 2021 and October 2022. This is significantly higher than the average of the last ten years, and six of the ten most severe mass balance years occurred since 2015. The European Alps saw record glacier melting due to a combination of factors, and glaciers in High Mountain Asia, western North America, South America, and parts of the Arctic also saw significant losses. The Greenland Ice Sheet experienced a negative mass balance for the 26th consecutive year, and globally, glaciers lost over 6000 Gt of ice between 1993 and 2019.
- Antarctic Sea Ice: The Antarctic sea ice reached a record low of 1.92 million km2 on February 25, 2022, which is almost 1 million km2 less than the long-term (1991-2020) average. It remained below average for the rest of the year, with record lows in June and July. Meanwhile, the Arctic sea ice tied for the 11th lowest monthly minimum ice extent in the satellite record at the end of the summer melt in September.
- Ocean Heat Content: In 2022, the ocean’s heat content reached a new observed high, breaking previous records. Greenhouse gases trap a significant amount of energy in the climate system, with around 90% of it being absorbed by the ocean, which could mitigate even higher temperature increases but threatens marine ecosystems. The rate of ocean warming has been very high over the last 20 years. Even with La Niña conditions continuing, marine heatwaves occurred in 58% of the ocean’s surface in 2022.
- Global Mean Sea Level: In 2022, the global mean sea level rose to a new high, as measured by satellite altimeters from 1993-2022. The rate of sea level rise has doubled in the past two decades, with a faster rate from 2013-2022 than from 1993-2002. From 2005-2019, melting land ice from glaciers, Greenland, and Antarctica contributed to 36% of the sea level rise, while warming oceans through thermal expansion contributed 55%, and variations in land water storage contributed less than 10%.
- Ocean Acidification: When carbon dioxide combines with seawater, it leads to a drop in pH levels, also known as ocean acidification. This is a major concern for marine organisms and the services they provide. According to the IPCC Sixth Assessment Report, the pH levels on the surface of open oceans have reached the lowest point in at least 26,000 years, and the rate of this change is unprecedented.
Socio-Economic and Environmental Consequences
- East Africa has been suffering from drought, with below-average rainfall in five consecutive wet seasons, resulting in over 20 million people facing acute food insecurity in the region as of January 2023.
- Pakistan experienced extensive flooding in July and August, with over 1,700 deaths, 33 million people affected, and almost 8 million people displaced, causing damage and economic losses of US$ 30 billion.
- Europe had record-breaking heatwaves in the summer, which led to excess deaths of over 15,000 across several countries. China also experienced its most extensive and long-lasting heatwave on record, resulting in the hottest and second-driest summer on record.
- Food insecurity affected 2.3 billion people in 2021, with 924 million facing severe food insecurity, and projections estimated that 767.9 million people would face undernourishment in 2021.
- Heatwaves in India and Pakistan in 2022 led to a decline in crop yields and threatened the availability and stability of staple foods.
- Somalia had almost 1.2 million internally displaced people due to drought, with over 60,000 people crossing into Ethiopia and Kenya during the same period.
- Climate change is having significant impacts on ecosystems, including the expansion of the temperate zone in the Tibetan Plateau and the disruption of recurring natural events like cherry blossom flowering in Japan. The timing of spring events, such as bird migration, is also becoming mismatched with other important events, potentially contributing to declines in some bird populations.