May 18, 2022 | Published by |

Originally published by Scimex – 18/05/22

The World Meteorological Organization (WMO) has released the latest State of the Global Climate report, which states that four key climate change indicators – greenhouse gas concentrations, sea-level rise, ocean heat and ocean acidification – set new records in 2021. According to the WMO this is another clear sign that human activities are causing planetary-scale changes on land, in the ocean, and in the atmosphere, with harmful and long-lasting ramifications for sustainable development and ecosystems.

Journal/conference: World Meteorological Organization (WMO)

Organisation/s: World Meteorological Organization (WMO)

Funder: UN

Media release

From: World Meteorological Organization (WMO)

Four key climate change indicators break records in 2021


Geneva, 18 May 2022 (WMO) – Four key climate change indicators – greenhouse gas concentrations, sea level rise, ocean heat and ocean acidification – set new records in 2021. This is yet another clear sign that human activities are causing planetary scale changes on land, in the ocean, and in the atmosphere, with harmful and long-lasting ramifications for sustainable development and ecosystems, according to the World Meteorological Organization (WMO).

Extreme weather – the day-to-day “face” of climate change – led to hundreds of billions of dollars in economic losses and wreaked a heavy toll on human lives and well-being and triggered shocks for food and water security and displacement that have accentuated in 2022.

The WMO State of the Global Climate in 2021 report confirmed that the past seven years have been the warmest seven years on record. 2021 was “only” one of the seven warmest because of a La Niña event at the start and end of the year. This had a temporary cooling effect but did not reverse the overall trend of rising temperatures. The average global temperature in 2021 was about 1.11 (± 0.13) °C above the pre-industrial level.

It is just a matter of time before we see another warmest year on record,” said WMO Secretary-General Prof. Petteri Taalas. “Our climate is changing before our eyes. The heat trapped by human-induced greenhouse gases will warm the planet for many generations to come. Sea level rise, ocean heat and acidification will continue for hundreds of years unless means to remove carbon from the atmosphere are invented. Some glaciers have reached the point of no return and this will have long-term repercussions in a world in which more than 2 billion people already experience water stress.”

“Extreme weather has the most immediate impact on our daily lives.Years of investment in disaster preparedness means that we are better at saving lives, though economic losses are soaring. But much more needs to be done, as we are seeing with the drought emergency unfolding in the Horn of Africa, the recent deadly flooding in South Africa and the extreme heat in India and Pakistan. Early Warning Systems are critically required for climate adaptation, and yet these are only available in less than half of WMO’s Members. We are committed to making early warnings reach everyone in the next five years, as requested by the United Nations Secretary-General Antonio Guterres,” said Prof. Taalas.

The WMO State of the Global Climate report complements the IPCC Sixth Assessment report, which includes data up to 2019. The new WMO report provides information and practical examples for policy-makers on how the climate change indicators outlined in the IPCC reports played out during the recent years globally and how the associated implications on extremes have been felt at national and  regional level in 2021.

The report was released just ahead of the World Economic Forum Davos 2022 Annual Meeting, which brings together more than 2,000 leaders and experts from around the world under the theme Working Together, Restoring Trust. Topics on the agenda will include tackling climate change.

The WMO State of the Global Climate report, which will be used as an official document for the UN Climate Change negotiations known as COP27 to take place in Egypt later this year.

Dozens of experts contribute to the report  from Member-States including National Meteorological and Hydrological Services (NMHSs) and  Global Data and Analysis Centers, as well as Regional Climate Centres, the World Climate Research Programme (WCRP), the Global Atmosphere Watch (GAW), the Global Cryosphere Watch and the EU’s Copernicus Climate Change services.

United Nations partners include the Food and Agriculture Organization of the United Nations (FAO), Intergovernmental Oceanographic Commission of UNESCO (UNESCO-IOC), International Organization for Migration (IOM), the United Nations Environment Programme (UNEP), UN High Commissioner for Refugees (UNHCR), the UN Office for Disaster Risk Reduction (UNDRR) and the World Food Programme (WFP).

Key Messages


Greenhouse gas concentrations reached a new global high in 2020, when the concentration of carbon dioxide (CO2) reached 413.2 parts per million (ppm) globally, or 149% of the pre-industrial level. Data from specific locations indicate that they continued to increase in 2021 and early 2022, with monthly average CO2 at Mona Loa in Hawaii reaching 416.45 ppm in April 2020, 419.05 ppm in April 2021, and 420.23 ppm in April 2022.

The global annual mean temperature in 2021 was around 1.11 ±0.13 °C above the 1850-1900 pre-industrial average, less warm than some recent years owing to cooling La Niña conditions at the start and end of the year. The most recent seven years, 2015 to 2021, are the seven warmest years on record. 

Ocean heat was record high. The upper 2000m depth of the ocean continued to warm in 2021 and it is expected that it will continue to warm in the future – a change which is irreversible on centennial to millennial time scales. All data sets agree that ocean warming rates show a particularly strong increase in the past two decades. The warmth is penetrating to ever deeper levels. Much of the ocean experienced at least one ‘strong’ marine heatwave at some point in 2021.

Ocean acidification. The ocean absorbs around 23% of the annual emissions of anthropogenic CO2 to the atmosphere. This reacts with seawater and leads to ocean acidification, which threatens organisms and ecosystem services, and hence food security, tourism and coastal protection. As the pH of the ocean decreases, its capacity to absorb CO2 from the atmosphere also declines. The IPCC concluded that “there is very high confidence that open ocean surface pH is now the lowest it has been for at least 26,000 years and current rates of pH change are unprecedented since at least that time.

Global mean sea level reached a new record high in 2021, after increasing at an average 4.5 mm per year over the period 2013 -2021. This is more than double the rate of between 1993 and 2002 and is mainly due to the accelerated loss of ice mass from the ice sheets. This has major implications for hundreds of millions of coastal dwellers and increases vulnerability to tropical cyclones.

Cryosphere: Although the glaciological year 2020-2021 saw less melting than in recent years, there is a clear trend towards an acceleration of mass loss on multi-decadal timescales. On average, the world’s reference glaciers have thinned by 33.5 meters (ice-equivalent) since 1950, with 76% of this thinning since 1980. 2021 was a particularly punishing year for glaciers in Canada and the US Northwest with record ice mass loss as a result of heatwaves and fires in June and July.  Greenland experienced an exceptional mid-August melt event and the first-ever recorded rainfall at Summit Station, the highest point on the ice sheet at an altitude of 3 216 m.


Exceptional heatwaves broke records across western North America and the Mediterranean. Death Valley, California reached 54.4 °C on 9 July, equalling a similar 2020 value as the highest recorded in the world since at least the 1930s, and Syracuse in Sicily reached 48.8 °C. The Canadian province of British Columbia, reached 49.6 °C on 29 June, and this contributed to more than 500 reported heat-related deaths and fuelled devastating wildfires which, in turn, worsened the impacts of flooding in November.

Flooding induced economic losses of US$17.7 billion in Henan province of China, and Western Europe experienced some of its most severe flooding on record in mid-July associated with economic losses in Germany exceeding US$20 billion. There was heavy loss of life.

Drought affected many parts of the world, including the Horn of Africa, Canada, the western United States, Iran, Afghanistan, Pakistan and Turkey. In sub-tropical South America, drought caused big agricultural losses and disrupted energy production and river transport. The drought in the Horn of Africa has intensified so far in 2022. Eastern Africa is facing the very real prospect that the rains will fail for a fourth consecutive season, placing Ethiopia, Kenya and Somalis into a drought of a length not experienced in the last 40 years. Humanitarian agencies are warning of devastating impacts on people and livelihoods in the region.

Hurricane Ida was the most significant of the North Atlantic season, making landfall in Louisiana on 29 August, with economic losses in the United States estimated at US$75 billion. 

The ozone hole over the Antarctic was unusually large and deep, reaching its maximum area of 24.8 million km2  (the size of Africa) as a result of a strong and stable polar vortex and colder than average conditions in the lower stratosphere. 

Food security:  The compounded effects of conflict, extreme weather events and economic shocks, further exacerbated by the COVID-19 pandemic, undermined decades of progress towards improving food security globally.  Worsening humanitarian crises in 2021 have also led to a growing number of countries at risk of famine. Of the total number of undernourished people in 2020, more than half live in Asia (418 million) and a third in Africa (282 million).

Displacement:  Hydrometeorological hazards continued to contribute to internal displacement. The countries with the highest numbers of displacements recorded as of October 2021 were China (more than 1.4 million), the Philippines (more than 386 000) and Viet Nam (more than 664 000).  

Ecosystems: including terrestrial, freshwater, coastal and marine ecosystems – and the services they provide, are affected by the changing climate and some are more vulnerable than others. Some ecosystems are degrading at an unprecedented rate. For example, mountain ecosystems – the water towers of the world – are profoundly affected. Rising temperatures heighten the risk of irreversible loss of marine and coastal ecosystems, including seagrass meadows and kelp forest. Coral reefs are especially vulnerable to climate change. They are projected to lose between 70 and 90% of their former coverage area at 1.5 °C of warming and over 99% at 2 °C. Between 20 and 90% of current coastal wetlands are at risk of being lost by the end of this century, depending on how fast sea levels rise. This will further compromise food provision, tourism, and coastal protection, among other ecosystem services.

Notes to Editors

Information used in this report is sourced from a large number of National Meteorological and Hydrological Services (NMHSs) and associated institutions, as well as Regional Climate Centres, the World Climate Research Programme (WCRP), the Global Atmosphere Watch (GAW), the Global Cryosphere Watch and the EU’s Copernicus Climate Change services. United Nations partners include the Food and Agriculture Organization of the United Nations (FAO), Intergovernmental Oceanographic Commission of UNESCO (UNESCO-IOC), International Organization for Migration (IOM), the United Nations Environment Programme (UNEP), UN High Commissioner for Refugees (UNHCR), the UN Office for Disaster Risk Reduction (UNDRR and the World Food Programme (WFP).

WMO extends its gratitude for all the dedicated hard work from WMO’s network of experts which makes this report an authoritative source of information on the state of the climate and on climate impacts. We are especially grateful to the UK Met Office, which acted as lead author of this report.

Where possible the WMO climatological standard normal, 1981-2010, is used as a base period for consistent reporting. For some indicators however, it is not possible to use this baseline due to a lack of measurement during the whole period or because a longer period is needed to calculate representative statistics.

For global mean temperature, a baseline of 1850-1900 is used. This is the baseline used in recent IPCC reports as a stand in for pre-industrial temperatures and is relevant for understanding progress relative to the aims of the Paris Agreement.

WMO uses six international datasets for temperatures HadCRUT.5.0.1.0 (UK Met Office), NOAAGlobalTemp v5 (USA), NASA GISTEMP v4 (USA), Berkeley Earth (USA), ERA5 (ECMWF), JRA-55 (Japan).

Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Ian Lowe is Emeritus professor of science, technology and society at Griffith University, Qld and former President of the Australian Conservation Foundation.

“The new WMO report makes grim reading. It documents the acceleration of climate change. The last seven years are the seven warmest ever, sea-level rise is speeding up as the oceans become warmer and the world’s seas are becoming more acidic.

Unless we take urgent action to reduce the burning of fossil fuels, there will be no chance of saving the Great Barrier Reef. With worse heat waves, flood events and wildfires, the world is already paying a high price for the decades of inaction since the science became clear.

As we go to the polls this week, we should all be aware of our responsibility to elect representatives who will treat climate change with the urgency it demands.”

Last updated: 17 May 2022 5:26pm

Declared conflicts of interest:

None declared.

Professor Mark Howden is Director of the ANU Institute for Climate, Energy and Disaster Solutions and a Vice-Chair of the IPCC Working Group II

“The record levels of atmospheric carbon dioxide, global temperature, sea-level rise and ocean heat and acidification reported by the WMO are, unfortunately, not at all surprising. They are consistent with long and strong global trends in all of these key metrics, which are driven in turn by continued record levels of GHG emissions – in spite of the temporary reductions in emissions caused by COVID lockdowns and in spite of the emission-reduction commitments made last year at Glasgow and at previous global meetings. These trends really matter to Australia and Australians impacting on every sector of our economy, our environment and our health. New records will continue to be broken and the damages will continue to accumulate until we take our foot off the climate change accelerator.”

Last updated: 17 May 2022 5:25pm

Declared conflicts of interest:

None declared.

Dr Tom Mortlock is a Senior Analyst at Aon and Adjunct Fellow at Macquarie University

“The WMO report is another reminder of how climate change is playing out right in front of our eyes.

The report highlights that atmospheric CO2 has now surpassed 420 ppm (parts per million) in 2022. To put this into perspective, ice core records in Antarctica suggest that atmospheric CO2 naturally fluctuates between 150 and 300 ppm.

We are now probably 40 per cent above natural levels of CO2 experienced over the last million years of Earth’s history, and this has all happened in the past 150 years.

It is now unequivocal that this recent period of warming has been driven by human-produced greenhouse gas emissions. If we want to avoid the worst impacts of climate change, we must limit warming to 1.5 degrees in line with the Paris agreement.”

Last updated: 17 May 2022 5:23pm

Declared conflicts of interest:

None declared.

Professor Colin Butler is an Honorary Professor at the National Centre for Epidemiology and Population Health at the Australian National University

“The WMO State of the Global Climate in 2021 report is a terrifying warning for human health and well-being. The report notes that “compounded effects of conflict, extreme weather events and economic shocks, further exacerbated by the COVID-19 pandemic” have “undermined decades of progress towards improving food security globally.” The pattern and trends affecting adverse planetary change are clear; as someone who first published about climate change and health over 30 years ago (1991) the implications are frightening.

Without urgent action to lower carbon emissions, millions of people, in the not far distant future, will die, primarily from hunger and from fighting over limited resources, made scarcer by climate change. For example, the current heatwave in India (mentioned in the press release) is reducing Indian wheat yields and wheat exports. Combined with the loss of Ukrainian food exports (especially of wheat) food prices will rise even more, probably leading to food riots as well as worsening nutrition for hundreds of millions of people.

Australians are not insulated from these intensifying shocks; we depend on a reliable and stable international system. Climate change (interacting with many other factors related to Limits to Growth) places this stability at great risk.”

Last updated: 17 May 2022 5:22pm

Declared conflicts of interest:

None declared.

Professor Pete Strutton is from the Institute for Marine and Antarctic Studies at the University of Tasmania and the ARC Centre of Excellence for Climate Extremes

“Like the recent IPCC reports, the WMO State of the Global Climate in 2021 report confirms that atmospheric carbon dioxide continues to increase, air temperatures are still warming, and the oceans are warming and acidifying while sea level rises. Many of these changes are still accelerating, and extreme events such as droughts, fires and floods are increasing in frequency and severity.

Against this background, it should come as no surprise that Australians increasingly list climate change as their primary concern at this federal election. We have to make enormous progress towards net zero this decade if we are to have even a 50% chance of limiting warming to 1.5°C. Net-zero by 2050 is too late to avoid 2°C warming with certainty.”

Last updated: 17 May 2022 5:20pm

Declared conflicts of interest:

None declared.

Associate Professor Douglas Bardsley is from the School of Social Sciences at the University of Adelaide 

“This report emphasises how important it is now for our society to incorporate the risk of climate change into its planning for the future.

We are already experiencing unprecedented climatic conditions, but the world is going to see a lot more climate change this century irrespective of what humanity does to mitigate greenhouse gas emissions. Society must plan for the new levels of climate risk and that means anticipating the future and building resilience into all of our important systems.

Food security risk is just one of the issues emphasised in the report, and there is much we can do to secure the land and water resources for producing food in Australia, but we are not implementing many of those adaptation responses yet.

Similarly, the risks of hazards such as bushfire and coastal flooding will increase with climate change, but we are still building in areas highly exposed to those risks without accounting for the likely future impacts to those places.

The decisions we make now will increase or decrease the ability for all of our systems to adapt to the climate change ahead.”

Last updated: 17 May 2022 5:18pm

Declared conflicts of interest:

None declared.