The Global Climate 2011-2020

A decade of accelerating climate change

The global climate system is complex.

In order to unpack such complexity, the WMO State of the Global Climate uses seven Climate Indicators to describe the changing climate—providing a broad view of the climate at a global scale. They are used to monitor the domains most relevant to climate change, including the composition of the atmosphere, the energy changes that arise from the accumulation of greenhouse gases and other factors, as well as the responses of land, oceans and ice.

The decadal reports differ from annual reports by taking analyzing these indicators over longer periods of time. This allows trends, such as acceleration, to become more visible.


Greenhouse Gases

Increasing levels of greenhouse gases in the atmosphere due to human activities are a major driver of climate change.

The atmospheric concentrations of greenhouse gases reflect a balance between sources, emissions from human activities, and sinks.

Each of the past three decades has had successively higher fossil fuel CO 2  emissions.

Although the change might not look significant, concentrations of greenhouse gases are not just growing, they are accelerating.

Explore the charts to find out the growth rates from one decade to the next.

The accelerating change in methane (CH 4 ) concentration has been even more pronounced: the growth rate between decades has nearly doubled.

The acceleration in methane has been driven by the growth in emissions from agriculture, waste, and fossil fuel production and use, though natural emissions from wetlands have also contributed to a smaller degree.

It's not all bad news:

Thanks to actions taken under the Montreal Protocol, the ozone hole was smaller in 2011-2020 than the two previous decades.

Global Mean Surface Temperature

As greenhouse gas concentrations rise, so does global mean surface temperature (GMST). GMST is measured using a combination of air temperature over land, and sea surface temperature in ocean areas, typically expressed as a difference from a baseline period.

At approximately 1.10° above the pre-industrial average (1850-1900), it was the warmest decade on record by a clear margin.

Each successive decade since the 1990s has been warmer than all previous decades.

Another indicator of long-term changes in extreme heat is the occurrence of record high temperatures.

Of 96 WMO Members who reported their highest temperatures from 1961-2020, 37 reported their highest temperature during 2011-20, and 2 more their equal-highest, higher than in any other decade, and nearly twice as much as the previous decade.

Precipitation

Compared to temperature, precipitation is characterized by higher spatial and temporal variability.

There were large differences in precipitation by region over the decade.

Some regions had an abnormally dry decade. Long-term drought was predominant in many subtropical regions, including the south-western United States, the western Mediterranean, eastern Australia south of the tropics, southern Africa, central Chile and northeast Brazil.

On the other hand, the decade shows above average to extreme wet conditions across most of Asia. The year 2020 was exceptionally wet in parts of China and Pakistan.

Ocean Heat Content

As greenhouse gases accumulate in the atmosphere, temperatures warm on land and in the ocean.

Around 90% of the excess energy that accumulates in the earth system due to increasing concentrations of greenhouse gases, goes into the ocean.

Ocean Heat Content measures how this energy warms the ocean at various depths down to 2000m deep.

It is expected that the ocean will continue to warm well into the future a change which is irreversible on centennial to millennial time scales.

The upper 2000m depth of the ocean continued to warm throughout 2011-2020, reaching a record high in 2020.

This continues a sequence of record years that began in 2013 in most data sets, and it is expected that this trend will continue in the future.

But why does ocean warming matter?

Coral bleaching

Corals are extremely sensitive to temperature changes. Their health is vital as they create entire ecosystems, serve as a source of food for millions, protect coastlines from storms and erosion and can be key tourist attractions.

Sea Level Rise

As water warms, it expands. Therefore, rising ocean temperatures are a key contributor to rising sea levels around the globe.

Sea Level Rise

The global sea level is rising for a number of reasons.

Ocean warming and melting ice sheets and glaciers all contribute to overall rise.

Between 2011-2020, sea level rose at a rate of approximately 4.5mm/yr.

In the previous decade (2001-2010), sea levels rose at a rate of rate of only 2.9mm/yr.

This means sea level rise is also accelerating.

Since 1993, the acceleration of rise has been estimated at approximately 0.11mm/yr 2 .

 

Ocean Acidification

Rising greenhouse gas concentrations impact the planet in other ways besides warming.

Another impact of rising CO 2  concentration is ocean acidification.

The ocean absorbs around 25% of the annual emissions of anthropogenic CO 2  to the atmosphere, helping to alleviate the impacts of climate change but at a high ecological cost to the ocean.

CO 2  reacts with seawater and increases its acidity. It endangers organisms and ecosystem services, including food security, by endangering fisheries and aquaculture. It also affects coastal protection by weakening coral reefs, which shield the coastline, and encourage tourism.

As the pH of the ocean decreases, meaning that its acidity increases, its capacity to absorb CO 2  from the atmosphere also declines.

Global mean ocean pH has been steadily declining at rates not seen for at least the past 26,000 years.

As more CO 2  is added to the ocean, there is a greater abundance of hydrogen ions (H+), and the water becomes more acidic.

However, this doesn't happen uniformly. Some areas of the ocean are becoming more acidic than others.

Sea Ice Extent

Changes in global temperature resulting from increasing greenhouse gases also impact bodies of ice, both at sea and on land.

Sea ice extent is estimated from measurements taken from satellites.

It serves as a useful indicator of climate change, particularly given how quickly change occurs in the Arctic and how widespread the repercussions of changes in its cover can be.

Arctic Sea Ice

Arctic sea-ice extent continued to decline from 2011-2020, particularly during the summer melt season.

Arctic Sea Ice

The mean seasonal minimum during the 2011-2020 period was 4.37 million km 2 , 30% below the 1981-2010 average of 6.22 million km 2 .

Antarctic Sea Ice

By contrast, Antarctic sea ice extent shows no clear long-term trend. Overall, mean sea ice extent for the decade was close to the average of the preceding years.

Ice Sheets

The Greenland and Antarctic Ice Sheets are the largest freshwater reservoirs on Earth, storing a volume of 29.5 million km 3  of frozen water.

When ice sheets lose mass, they directly contribute to raising sea level. Monitoring the volume of ice they gain or lose is therefore critical to assessing sea level change.

During the 2011-2020 decade, Greenland lost mass at an average rate of 251 Gt/yr and reached a new record mass loss of 444 Gt in 2019.

Antarctica lost ice at an average rate of 143 Gt yr -1  during this decade, nearly 75% more than the rate of the previous decade.

Glacier Mass Balance

Glaciers are found around the world, with many in the high mountain ranges of Asia, and North and South America.

They are formed from snow that has compacted to ice, which then flows downhill to lower, warmer altitudes, where it melts.

Glaciers provide ecosystem services and freshwater to millions around the world. As they shrink, there are significant and direct impacts on both the global climate and sustainable development.

Approximately 40 of the glaciers monitored worldwide by the World Glacier Monitoring Service have long-term observations and are used to estimate glacier mass balance.

The glaciers have been losing mass nearly every year since records began.

From 2011-2020, glacial loss was nearly double the previous decade.

On average, measured glaciers thinned by approximately 1m per year.

What does mass loss look like? Swipe to see how glaciers are shrinking in Switzerland:

View of Vadret da Tschierva and Piz Roseg in 1935 (left) and 2022 (right) (Photo: swisstopo and VAW /  ETH Zurich )

Extreme Events

Rising global temperatures have contributed to more frequent and severe extreme weather events around the world, including cold and heat waves, floods, droughts, wildfires and storms. More details on specific events can be found in the report.

A selection of extreme events from 2011-2020, with triangular icons representing event types. Events are not intended to be exhaustive but rather representative of key extremes over the course of the decade. Click on any event for more information, including impacts to the SDGs.

Impacts to Sustainable Development

It is becoming increasingly clear that climate extremes are affecting our ability to develop sustainably.

National Case Studies

To help put the various components of climate change and development together, WMO, in partnership with various United Nations agencies and national statistics offices (NSOs), has piloted a project exploring the impact of extreme events on national progress toward the Sustainable Development Goals (SDGs).

Swipe to see select case studies ->

Drought in Somalia: 2010-2012

According to the Somali National Bureau of Statistics, the 2010-2012 drought led to “devastating and repeated loss of lives, livestock and crops”, and therefore had a major impact on progress toward SDGs 1 and 2. The drought coincided with a drop in humanitarian assistance and a spike in food prices, leading to a famine that claimed the lives of 258,000 people between October 2010 and April 2012,  including 133,000 children under the age of 5 . Additionally, despite copious investments in the water and sanitation sector, access to safe and adequate water supplies in Somalia remains a challenge. Pre-existing water shortages were exacerbated by the drought, which consequently increased water contamination, and therefore had a significant impact on health, water resources and ecosystems (SDGs 3, 6, & 15).

Reported impacts to SDGs from insignificant, significant to major.

Drought in Colombia: 2015-2016

Colombia experienced a record-breaking mega-drought from 2015 to 2016. Given that over  70 % of Colombia’s power mix  at that time came from hydropower plants, the drying up of rivers during the drought had a major impact on energy provision and infrastructure, particularly of aqueducts (SDGs 7 & 11). More than 300,000 people were affected by the drought, significantly impacting progress toward SDG 1. Additionally, in 2018, the percentage of people without access to clean water rose to nearly 8%, due at least in part to the direct and indirect effects of the drought (SDG 6). However, individuals were not the only ones affected—glacial mass loss was also higher than average from 2015 to 2017.

Reported impacts to SDGs from insignificant, significant to major.

Antigua & Barbuda: Hurricane Irma (2017)

Hurricane Irma had a devastating impact on the Caribbean. Antigua and Barbuda was among the worst hit and was therefore chosen as a case study for understanding the development impact of tropical cyclones. One of the major impacts cited was economic, given the fact that Hurricane Irma led to an approximate 1.1% loss of GDP (SDG 1). The tourism and infrastructure sectors suffered the gravest impact, and this hindered the country’s progress toward SDG 11. According to  a joint assessment  conducted by the Government of Antigua and Barbuda, the EU and the World Bank, the combined damage and loss estimate for the infrastructure sector was approximately USD 21 million. The housing sector was also significantly affected, with 95% of houses damaged on Barbuda, and 45% left uninhabitable (SDG 10). Minor damage was also reported to the agriculture, health, and water sectors (SDGs 2, 3, and 6).

Reported impacts to SDGs from insignificant, significant to major.

2019 European Heatwaves: Belgium

Belgium, the United Kingdom, and the Netherlands were surveyed in order to understand the impact of the 2019 heatwave on national development. NSOs from the three countries reported differentiated impacts. Belgium identified a major impact to the economy (SDG 1), particularly due to heat-related mortality, with approximately 400 more deaths than average (SDG 3), a loss of crop production (SDG 2) and a significant drop in inland waterway transport.

Reported impacts to SDGs from insignificant, significant to major.

2019 European Heatwaves: United Kingdom

The United Kingdom identified a significant impact on SDG 1, citing 863 excess deaths in England over the summer 2018 period.

Reported impacts to SDGs from insignificant, significant to major.

2019 European Heatwaves: Netherlands

The Netherlands identified a significant impact on SDGs 3, 6, 7 and 15, citing known issues of heat-related mortality, water availability and disrupted ecosystem services during the heatwave.  

Reported impacts to SDGs from insignificant, significant to major.

Overall Findings

Progress toward SDG 1: No Poverty and SDG 7: Clean Energy were the most frequently reported as being hampered by extreme events.

Lessons learned: Data Gaps & Challenges

  • Multi-sectoral quantitative/qualitative analysis is not consistently done after every disaster, making it difficult to obtain a clear image of the overall impact to development.
  • Disaster data are often reported annually and not disaggregated by event, thereby presenting a challenge in attributing impacts to a single specific event.
  • Diverse components of the SDGs mean that different agencies across state, national and regional levels are responsible for housing different types of impact data.

Understanding how extreme events are impacting sustainable development is critical not only to support adaptation efforts, but also to serve as a basis for stronger climate action to mitigate worsening events in the future.

These case studies demonstrate the need for high-quality, accessible, timely and reliable disaggregated impact data, and for strengthened international collaboration between NSOs and United Nations agencies.

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Food Security

The distance towards many of the SDG 2 targets grows wider each year, even though the time remaining for reaching the 2030 target date for the SGDs is narrowing. While there are global and national efforts towards making progress on SDG 2, they are proving insufficient in the face of challenging and uncertain contexts and a changing climate.

While the new millennium began with a significant decline in the prevalence of undernourished persons at the global level, from 13.1% to 8.6% between 2001 and 2010, this trend remained stagnant over the following decade (2011-2020) and increased to 9.3% by 2020.

Achieving SDG 2 is tightly linked to climate risk management. For example, heat-stress conditions could result in food losses at the production stage.

Weather-related hazards such as landslides caused by heavy rains may affect road infrastructure, hindering transportation and access to markets, which then results in food spoilage and waste.

All four pillars of food security (access, availability, utilization, and stability) have been  threatened by intensified extreme weather hazards over the 2011-2020 period , and will and will subsequently affect the achievement of SDG 2 targets by 2030.

Health

As the world warms at a faster rate than at any point in recorded history, human health is on the frontline. Climate change threatens to reverse decades of progress towards better health and well-being, particularly in the most vulnerable communities.

Urban populations are growing and are particularly vulnerable to the increasing health risks from extreme heat and air pollution, which threaten the achievement of SDGs 3 and 11.

Most of the 4.4 billion people living in cities are particularly threatened by extreme heat exposure, air pollution that exceeds WHO guidelines, as well as other urban health risks.         

The IPCC states that climate change is projected to significantly increase exposure to heatwaves (very high confidence) and heat-related morbidity and mortality (high confidence).

Humans are also becoming more susceptible to infectious disease as the suitability of dengue and malaria transmission is increasing with changes to the global climate.

The climatic suitability for the transmission of dengue increased by around 12.0% from the 1951-1960 to 2012–2021 periods, causing febrile illnesses and, in severe cases, organ failure and death.

Health care is among the most important sectors in managing the effects of climate change but also has an important role in reducing its own carbon emissions.

High-emitting health systems need to transition to climate resilient and low carbon solutions to harness wider health co benefits.

Displacement & Migration

Throughout the decade, climate and weather-related hazards triggered displacement and increased the vulnerability and protection needs of those already displaced. Internally displaced people and refugees, migrants and asylum seekers were all affected by the impacts of weather-related hazards. Combined with other drivers, the impacts of disasters and climate change can jeopardize years or even decades of development gains and threaten the attainment of most SDGs.

Weather-related events were responsible for nearly 94% of all disaster displacement recorded over the last decade. An annual average of 22.1 million internal displacements were triggered by weather-related hazards between 2011 and 2020.

Floods triggered most of the internal displacements caused by weather-related hazards, with 123 million displacements, followed by storms, with 86 million.

Millions more have also been forced from their homes by drought, coastal erosion, rising sea levels, desertification and other slow-onset events.

Resilience to climate-related disasters, environmental degradation and displacement is often lowest conflict affected contexts. Many of today’s crises are shaped by a complex mix of climate and environmental change, disaster risk, conflict, and displacement.

People displaced in the context of climate change and disasters and their host communities are often faced with the loss of livelihoods which entrenches poverty (SDG 1) and hunger (SDG 2), direct threats to their lives and well-being (SDG 3), widened inequality gaps (SDG 10), limited access to quality education (SDG 4), water and sanitation (SDG 6) as well as clean energy (SDG 7). Due to pre-existing gender and socio-economic inequalities compounding their vulnerabilities, women and girls are among the worst impacted (SDG 5).

With the accelerating impacts of the climate emergency, it is increasingly important to account for the protection, human rights and humanitarian needs of those displaced, to prevent and minimize the negative impacts of displacement by preparing for climate- and weather-related disasters and environmental degradation and to build resilience for all people displaced and their host communities in order to ensure that “no one is left behind”.

Taking Action on Climate & the SDGs

 Climate action is the 21 st  century’s greatest opportunity to drive forward all the Sustainable Development Goals.

United Nations Secretary-General António Guterres

The connections between climate and the SDGs are not just negative.

In the 2023 Synthesis Report, the IPCC demonstrated that there are many more synergies between climate and SDG action than there are trade offs.

Building off this knowledge,  UNDESA and UNFCCC published a report  to strengthen the evidence base to show addressing climate change and achieving the SDGs are inextricably intertwined.

For example, one case study showed how the energy system transition across Africa's largest cities could significantly reduce global air pollution and, in so doing, prevent as many as 350,000 premature deaths across Accra, Cairo, Johannesburg, and Lagos  between 2023 and 2040 .

There are many more possibilities for synergistic action, across all sectors and regions.

We must solve the climate emergency and sustainable development challenges together, or we will not solve them at all.

How will you get in involved?

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© World Meteorological Organization, 2023

WMO uses datasets developed and maintained by the United States National Oceanic and Atmospheric Administration, NASA’s Goddard Institute for Space Studies, and the United Kingdom’s Met Office Hadley Centre and the University of East Anglia’s Climatic Research Unit in the United Kingdom.

It also uses reanalysis datasets from the European Centre for Medium Range Weather Forecasts and its Copernicus Climate Change Service, and the Japan Meteorological Agency. This method combines millions of meteorological and marine observations, including from satellites, with models to produce a complete reanalysis of the atmosphere. The combination of observations with models makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions.

Internationally recognized datasets are used for all other key climate indicators. Full details are available in the State of the Global Climate report.

Videos

National Geographic

Data Visualization

Claire Ransom, Benjamin Pire

View of Vadret da Tschierva and Piz Roseg in 1935 (left) and 2022 (right) (Photo: swisstopo and VAW /  ETH Zurich )

Reported impacts to SDGs from insignificant, significant to major.

Reported impacts to SDGs from insignificant, significant to major.

Reported impacts to SDGs from insignificant, significant to major.

Reported impacts to SDGs from insignificant, significant to major.

Reported impacts to SDGs from insignificant, significant to major.

Reported impacts to SDGs from insignificant, significant to major.

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