21st century

21st century

Remarkable new observation and modelling technologies continue to develop, helping advance understanding of the Earth’s complex global weather and climate system. As a result, today’s five-day forecasts are as reliable as the two-day forecast of 25 years ago. These advances translate into literally billions of dollars in economic gains. 

Local weather forecasts depend on real time access to observations from around the globe under the umbrella of WMO’s Integrated Global Observing System (WIGOS)

Currently, more  than 30 meteorological and 200 research satellites, 10 000 manned and automatic surface weather stations, 1 000 upper-air stations, 7 000 ships, more than 1 100 buoys, hundreds of weather radars and 3 000 specially equipped commercial aircraft measure key parameters of the atmosphere, land and ocean surface every day. These observations are then made freely available to every country in the world through the WMO Information System (WIS)

Meteorologists and climate scientists now make seasonal and longer term forecasts and are developing “seamless weather and climate forecasts” to meet the ever growing need for weather and climate services for key sectors such as agriculture, health, water, transport and energy. 

But it’s no longer just about weather and climate. As we continue to extend our prediction range and improve our understanding of the whole Earth System, the need has become paramount to strengthen data exchange in other areas such as hydrology, atmospheric composition, cryosphere and space weather

An increasingly diverse group of stakeholders are now active in the generation and use of data, including NMHSs, the private sector and academia. There is more Earth System data available than ever before, thanks to strides in ground and space-based remote sensing technology and in the processing speed and memory size of the computers used for meteorological modelling. 

In view of the rapidly evolving needs, an Extraordinary World Meteorological Congress approved the WMO Unified Data Policy in 2021. It provides a comprehensive update of the policies guiding the international exchange of weather, climate and related Earth system data and reaffirms the commitment to the free and unrestricted exchange of data, which has been the bedrock of the WMO community for the past 150 years. 

This  will help the WMO community strengthen and better sustain monitoring and prediction of all Earth-system components, with massive socioeconomic benefits as a result. It will lead to additional exchange of all types of environmental data, which in turn will enable all WMO Members to deliver better, more accurate and timely weather- and climate-related services. 



WMO’s State of the Global Climate reports have tracked changes in the climate system over the years. The reports show how key  climate change indicators – greenhouse gas concentrations, surface temperature, ocean heat, ocean acidification, glacier melt, sea ice loss, and sea level rise – are all at record observed highs. We are getting ever closer to the 1.5° C lower temperature limit of the Paris Agreement on Climate Change.  

Climate change is leading to more extreme weather and climate events such as longer and more intense heatwaves, heavier rainfall, and more severe droughts. Our vulnerability to the adverse impacts of weather events is increasing in many areas. More people than ever live either in megacities or in high-risk zones such as low-lying, exposed coastal areas and flood plains.   

Improved monitoring, prediction and communication capabilities are needed on both what the weather will be and what it will do, and to help society understand and adapt to the weather we may expect to see in the future. Given that many climate change impacts play out through water, integrated water and climate action is essential

Despite the huge technological strides, fundamental gaps remain in the global observing system. Far too many people in vulnerable countries lack even rudimentary early warnings that bad weather is heading their way. 

Half of countries globally do not have early warning systems and even fewer have regulatory frameworks to link early warnings to emergency plans.  Coverage is worst for developing countries on the front lines of climate change, namely Least Developed Countries (LDCs) and Small Island Developing States (SIDS). 

WMO is therefore spearheading a new Early Warnings for All initiative to ensure that everyone in the world is protected by early warning systems in the next five years. The initiative embraces the entire WMO community, the wider UN family, development banks and the private sector, including Big Tech companies.  

“We must boost the power of prediction for everyone and build their capacity to act. Let us recognize the value of early warnings and early action as critical tools to reduce disaster risk and support climate adaptation,” said UN Secretary-General António Guterres in announcing the campaign. 

Early warning systems are widely regarded as the “low-hanging fruit” for climate change adaptation because they are a relatively cheap and effective way of protecting people and assets from weather and climate extremes, including storms, floods and heatwaves to name a few.  It is estimated that they provide a tenfold return on investment.  

The Global Commission on Adaptation found that spending just US$800 million on such systems in developing countries would avoid losses of $3 to 16 billion per year. 

And the price tag to achieve this? The equivalent of 50 cents per person per year for the next five years