Background Image

Multi-agency report highlights increasing signs and impacts of climate change in atmosphere, land and oceans

Date: 11 March 2020

New York / Geneva, 10 March 2020 - The tell-tale physical signs of climate change such as increasing land and ocean heat, accelerating sea level rise and melting ice are highlighted in a new report compiled by the World Meteorological Organization and an extensive network of partners. It documents impacts of weather and climate events on socio-economic development, human health, migration and displacement, food security and land and marine ecosystems.

The WMO Statement on the State of the Global Climate in 2019 includes input from national meteorological and hydrological services, leading international experts, scientific institutions and United Nations agencies. The flagship report provides authoritative information for policy makers on the need for Climate Action.

The report confirms information in a provisional statement issued at the UN Climate Change Conference in December that 2019 was the second warmest year in the instrumental record. 2015-2019 are the five warmest years on record, and 2010-2019 the warmest decade on record. Since the 1980s, each successive decade has been warmer than any preceding decade since 1850.

2019 ended with a global average temperature of 1.1°C above estimated pre-industrial levels, second only to the record set in 2016, when a very strong El Niño event contributed to an increased global mean temperature atop the overall warming trend.

“We are currently way off track to meeting either the 1.5°C or 2°C targets that the Paris Agreement calls for,” said United Nations Secretary-General Antonio Guterres in a foreword.

“This report outlines the latest science and illustrates the urgency for far-reaching climate action. It brings together data from across the fields of climate science and lists the potential future impacts of climate change – from health and economic consequences to decreased food security and increased displacement,” he said.

The report was launched at a press conference given by the UN Secretary-General and WMO Secretary-General Petteri Taalas at UN headquarters on 10 March.

“Given that greenhouse gas levels continue to increase, the warming will continue. A recent decadal forecast indicates that a new annual global temperature record is likely in the next five years. It is a matter of time,” said WMO Secretary-General Taalas.

“We just had the warmest January on record. Winter was unseasonably mild in many parts of the northern hemisphere. Smoke and pollutants from damaging fires in Australia circumnavigated the globe, causing a spike in CO2 emissions. Reported record temperatures in Antarctica were accompanied by large-scale ice melt and the fracturing of a glacier which will have repercussions for sea level rise,” said Mr. Taalas.

“Temperature is one indicator of ongoing climate change. Changes in the global distribution of rainfall have had a major impact on several countries. Sea levels are rising at an increasing pace, largely due to the thermal expansion of sea water as well as melting of the largest glaciers, like in Greenland and Antarctica. This is exposing coastal areas and islands to a greater risk of flooding and the submersion of low-lying areas,” said Mr Taalas. 


Marine heatwaves: More than 90% of the excess energy accumulating in the climate system as a result of increased concentrations of greenhouse gases goes into the ocean. In 2019, ocean heat content down to a depth of 2 kilometres exceeded the previous record highs set in 2018.

Ocean warming has widespread impacts on the climate system and contributes more than 30% of sea level rise through thermal expansion of sea water. It is altering ocean currents and indirectly altering storm tracks and melting floating ice shelves. Together with ocean acidification and deoxygenation, ocean warming can lead to dramatic changes in marine ecosystems. In 2019, the ocean experienced on average nearly 2 months of unusually warm temperatures. At least 84% of the ocean experienced at least one marine heatwave.

Ocean Acidification: In the decade 2009-2018, the ocean absorbed around 23% of annual CO2 emissions, cushioning the impacts of climate change but increasing ocean acidity. The change of pH reduces the ability of marine organisms such as mussels, crustacean and corals to calcify, affecting marine life, growth and reproduction.

pCO2 measurement from the Hawaii Ocean Time Series long term observation station.   © IOC-UNESCO, NOAA-PMEL, IAEA OA-ICC
pCO2 measurement from the Hawaii Ocean Time Series long term observation station. © IOC-UNESCO, NOAA-PMEL, IAEA OA-ICC


pCO2 measurement from the Hawaii Ocean Time Series long term observation station. © IOC-UNESCO, NOAA-PMEL, IAEA OA-ICC
pCO2 measurement from the Hawaii Ocean Time Series long term observation station. © IOC-UNESCO, NOAA-PMEL, IAEA OA-ICC

Ocean Deoxygenation: both observations and models indicate that oxygen is declining in the open and coastal oceans, including estuaries and semi-enclosed seas. Since the middle of the last century, there has been an estimated 1%–2% decrease (77 billion–145 billion tons) in the global ocean oxygen inventory.

Marine Ecosystems: Deoxygenation alongside ocean warming and acidification is now seen as a major threat to ocean ecosystems and the wellbeing of people that depend on them. Coral reefs are projected to decline to 10%-30% of former cover at 1.5°C warming, and to less than 1% at 2°C warming.

Sea level has risen throughout the satellite altimetery record (since 1993), but the rate has increased over that time, mainly due to melting of ice sheets on Greenland and Antarctica. In 2019, the global mean sea level reached its highest value on the record. 

Ice: The continued long-term decline of Arctic sea ice was confirmed in 2019. The September monthly average extent (usually the lowest of the year) was the third lowest on record with the daily minimum extent tied for second lowest.

Until 2016, Antarctic sea ice extent had shown a small long-term increase. In late 2016 this was interrupted by a sudden drop in extent to extreme low values. Since then, Antarctic sea-ice extent has remained at relatively low levels.

The Greenland ice sheet has recorded nine of the 10 lowest surface mass balance years in the last 13 years. And 2019 was the 7th lowest on record. In terms of total mass balance. Greenland lost about 260 Gt of ice per year over the period 2002-2016, with a maximum of 458 Gt in 2011/12. The loss in 2019 was 329 Gt, well above the average.

Glaciers: Preliminary results from the World Glacier Monitoring Service indicate that 2018/19 was the 32nd consecutive year of negative mass balance for selected reference glaciers. Eight out of the ten most negative mass balance years were recorded since 2010.

Climate-related Impacts

The report devotes an extensive section to weather and climate impacts on human health, food security, migration, ecosystems and marine life. This is based on input from a wide variety of United Nations partners. (See in Editor’s note for full list)

High impact events

Tropical cyclones: Tropical cyclone activity globally in 2019 was above average. The Northern Hemisphere had 72 tropical cyclones. The 2018-19 Southern Hemisphere season was also above average, with 27 cyclones. Tropical Cyclone Idai made landfall in Mozambique on 15 March as one of the strongest known on the east coast of Africa, resulting in many casualties and widespread devastation. Idai contributed to the complete destruction of close to 780 000 ha of crops in Malawi, Mozambique, and Zimbabwe, further undermining a precarious food security situation in the region. The cyclone also resulted in at least 50 905 displaced persons in Zimbabwe, 53 237 in southern Malawi and 77 019 in Mozambique. One of the year’s most intense tropical cyclones was Dorian, which made landfall with category 5 intensity in the Bahamas. The destruction was worsened as it was exceptionally slow-moving and remained near-stationary for about 24 hours. Typhoon Hagibis made landfall west of Tokyo on 12 October, causing severe flooding.

Adapted from WMO Press release on the WMO Statement on the State of the Global Climate in 2019.


Notes for Editors

National Meteorological and Hydrological Services, WMO Regional Climate Centres, and dozens of scientific experts contributed to this report.

United Nations Agencies: Information has been supplied by the Food and Agriculture Organization of the United Nations(FAO), the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO), the International Monetary Fund, the International Organization for Migration (IOM), UN Environment, the UN Office for Disaster Risk Reduction, the United Nations High Commissioner for Refugees (UNHCR), the UN Conference on Trade and Development, World Food Programme and World Health Organization.

Data Centres: Global Precipitation Climatology Centre (GPCC); Met Office Hadley Centre; National Oceanic and Atmospheric Administration National Centres for Environmental Information (NOAA NCEI); European Centre for Medium-range Weather Forecasts (ECMWF) and Copernicus Climate Change Service (C3S); National Aeronautics and Space Administration Goddard Institute for Space Studies (NASA GISS); Japan Meteorological Agency (JMA); WMO Global Atmospheric Watch (GAW); NOAA National Ocean Data Center (NODC); National Snow and Ice Data Center (NSIDC); Mauna Loa Observatory; the Blue Carbon Initiative; Hong Kong Observatory; Pan-Arctic Regional Climate Outlook Forum (PARCOF); European Space Agency (ESA) Climate Change Initiative (CCI); Copernicus Marine Environmental Monitoring Service (CMEMS); Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO); the Polar Portal; Department of Physical Oceanography, Woods Hole Oceanographic Institution; Arctic and Antarctic Research Institute (AARI); Mercator Ocean; Global Ocean Oxygen Network (GO2NE); Global Ocean Acidification Observing Network (GOA-ON); Ocean and Sea Ice Satellite Application Facility (OSISAF) of European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT); Australian Bureau of Meteorology; Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere.

Full details of all the contributors are available in the Statement on the State of the Climate 2019

For further information contact: