April 2009

World Meteorological Day 2009

“Weather, climate and the air we breathe”


Each year, on 23 March, WMO—the Secretariat and its 188 Members—and the worldwide meteorological community celebrate World Meteorological Day. This Day commemorates the entry into force, on that date in 1950, of the WMO Convention creating the Organization. Subsequently, in 1951, WMO was designated a specialized agency of the United Nations System.

World Meteorological Day this year was celebrated around the theme: “Weather, climate and the air we breathe”. Scientists and medical professionals are increasingly aware of the critical linkages between weather, climate and the composition of the air we breathe. Gases and particles emitted to the atmosphere affect people’s health, as well as weather and climate.

This theme is particularly appropriate at a time when communities around the globe are struggling to attain the United Nations Millennium Development Goals, especially in terms of health, food, water security and poverty alleviation, as well as to increase their effectiveness in preventing and mitigating natural disasters, of which 90 per cent are directly related to weather, climate and water hazards and thereby fall within WMO’s mandate.

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WMO produced a kit for the occasion, containing a brochure, a poster and a message from the Secretary-General (all in English, French, Russian and Spanish). The kit may be obtained from the WMO Secretariat upon request. All these materials, as well as the presentations made by guests at the official ceremony are available online from the dedicated World Meteorological Day Website.

“Weather, climate and the air we breathe” was also the theme of the WMO Bulletin in January 2009.



As scientists analyse more data, they increasingly understand how closely air quality is connected to the weather-climate system. Weather variables control the transport and longevity of pollutants around the globe. The more scientists understand the weather-climate system, the better they are able to forecast the distribution of potentially harmful atmospheric particles and gases. The World Health Organization has estimated that an average of two million people die prematurely every year due to air pollution. At the same time, by taking into account the composition of the atmosphere, meteorologists are better able to make short-term weather forecasts and long-term climate predictions.

The WMO Global Atmosphere Watch (GAW) networks of stations collect data on greenhouse gases, such as carbon dioxide and methane, aerosols and reactive gases, including ozone, nitrogen oxides and sulphur dioxide. These observations work in concert with the vast weather, climate and water observational networks coordinated through the WMO Integrated Observing System.  National Meteorological and Hydrological Services use the data collected to produce air quality forecasting products, including air quality indexes that summarize the concentrations of several pollutants. GAW and the WMO World Weather Research Programme are expanding the suite of air quality services currently available, and work continues to better understand the effects of air pollution in various settings.

Additionally, scientists are increasingly incorporating the gases and particles emitted by human activities into climate models to better project future changes. The co-sponsored Intergovernmental Panel on Climate Change (IPCC), which is co-sponsored by WMO and the United Nations Environment Programme, concludes that the average global air surface temperature has increased about 0.74°C from 1905 to 2005. A warming climate can exacerbate air pollution. For example, climate change and land use are expected to increase desertification worldwide, thus increasing risk of sand and dust storms. Climate change models indicate that particle-producing fires will continue to increase in both frequency and intensity with rising global temperatures, as well as the risk of drought, which can lead to more fires.

World Climate Conference-3, which will be held in Geneva, Switzerland, from 31 August to 4 September 2009, will further explore the links between climate and health, especially looking at the impacts of climate variability and change on the occurrence of climate extremes. The Conference will engage scientists with decision-makers and policy-makers from the public and private sectors, with a session on climate and human health planned for 1 September.

A World Meteorological Day celebration was held at WMO headquarters. After a welcome address by the Secretary-General, guest speaker Gregory Carmichael Co-director, US Center for Global and Regional Environment Research, gave a presentation entitled “Globalization of air pollution”. Special guest, Maria Neira, Director, Department of Public Health and Environment, WHO, spoke on “Weather, climate, the air we breathe …  and health”.

podium   World Meteorological Day celebrations at the WMO Secretariat: (from left to right) special guest, Maria Neira, Director, Department of Public Health and Environment, WHO; Michel Jarraud, Secretary-General, WMO; guest speaker, Gregory Carmichael, Co-director, US Center for Global and Regional Environment Research; Jerry Lengoasa, Assistant Secretary-General, WMO



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