The natural environment suffers, for example, from lack of precipitation for extended periods and uncontrolled land use, leading to desertification. It is estimated that one-third of the Earth’s surface and one-fifth of the world’s population are threatened by desertification. WMO, therefore, directs its attention to the aspects of climate variability and change that impact the environment. The observational data of weather, climate and the atmosphere that are collected through the WMO networks of observing, data-transmitting and forecasting systems keep policy-makers informed of the state of the environment so that they are in a better position to prevent its further degradation and are used by used by the Intergovernmental Panel on Climate Change (IPCC) in its assessments of climate climate change, its potential impacts and options for adaptation and mitigation.
WMO is the recognized, comprehensive source of unique global systematic observations on the state of a wide variety of geophysical phenomena, datasets and long-term archives, and scientific and technical expertise in support of policy advice on various critical environmental issues.
Biodiversity (the variety of life on Earth and the natural patterns it forms) helps keep the global environment working. Polluted air, depleted or contaminated water, degraded soil and urban growth are all threats to biodiversity. Rising ocean temperatures are responsible for the widespread bleaching of coral reefs that support vast populations of marine life and are also important tourist attractions. Ecosystems such as wetlands, forests and lakes are an important part of the natural regime of a river. They are a buffer between river and terrestrial ecosystems and play an important role in storing or attenuating floodwaters. Stratospheric ozone protects plants, marine life, animals and people from solar ultraviolet radiation, which is harmful for life on Earth. Chlorofluorocarbons and other anthropogenic chemicals are responsible for the destruction of ozone. It is necessary, therefore, to ensure that all these Earth systems remain healthy.
An essential activity of National Meteorological and Hydrological Services is to monitor long-term changes in atmospheric greenhouse gases, ultraviolet radiation, aerosols and ozone, and to assess their consequent effects on people, climate, air and water quality and marine and terrestrial ecosystems. Another important activity is monitoring the atmospheric and water transport of dangerous particles in the wake of a volcanic explosion or an industrial accident.
The Global Atmosphere Watch (GAW) programme provides reliable scientific data and information on aerosols, greenhouse gases, selected reactive gases, ozone, ultraviolet radiation and precipitation chemistry (or atmospheric deposition). The GAW Urban Research Meteorology and Environment (GURME) project works together with the Group of Experts on Scientific Aspects of Marine Environmental Protection (GESAMP) as well as provides Sand and Dust Storms Warning (SDS-WAS). GAW recently initiated the Integrated Global Greenhouse Gas Information System (IG3S) that will use observations of greenhouse gases and inverse modelling techniques to support climate mitigations efforts. This new approach (explained in the animations below) supports of the UN Framework Convention on Climate Change (UNFCCC) and its Paris Agreement by providing an additional way of identifying and estimating urban and national emissions. It seeks to empower policymakers to take more effective action on mitigation.