Tracking climate change from space.

• Author: Leon, Juan Carlos Villagran De

For centuries, rural communities in the high plateaus of the Andes have utilized water from melting glaciers that typify this amazing mountain range. But the retreat of these glaciers is forcing the communities to reconsider their livelihoods and ways to adapt. From a wider perspective, the melting of glaciers is an iconic warning to the larger cities in the Andes that rely on glaciers for potable water. Unfortunately for these communities, the source of this particular problem and its potential solution lie far away from their arc of influence due to the fact that local actions contribute very little to remedy this problem.

As noted in 2003 and 2007 by the Intergovernmental Panel on Climate Change (IPCC) the melting of glaciers in the Andes, the Himalayas, and the Alps is a consequence of global warming, a process induced by humans, and directly related to industrialization that has fuelled this century, particularly in terms of demand for energy from fossil fuels. The emissions of greenhouse gases such as carbon dioxide ([CO.sub.2]), nitrous oxide ([N.sub.2]O), methane ([CH.sub.4]), and the emission of aerosols have a direct influence on the radiative forcing (the difference between incoming and outgoing radiation energy) in the atmosphere, leading to global warming. Such global warming manifests itself through higher temperatures in the oceans and the atmosphere. In the case of oceans, heat absorption is the main factor leading to the increase in their levels. In the case of glaciers and polar caps, it leads to melting of ice. As expected, the melting of glaciers and ice in continental land masses in Antarctica and Greenland also contributes to the increase in sea level.

Governments recognized the need to address this problem at the global level, and established the IPCC to provide the scientific basis on which to characterize the scale and depth of the problem, and the United Nations Framework Convention on Climate Change (UNFCCC) as the mechanism to facilitate the political discussion on this issue at the international level. Organizations within the United Nations also play other relevant roles. For example, the World Meteorological Organization (WMO) has long supported the establishment and operation of national meteorological departments or offices which generate the data that are required to monitor the Essential Climate Variables (ECVs) such as air and water temperatures, sea ice, water vapour and salinity, etc. In addition, WMO...