Plant Analysis Provides Clue to Earth’s Future
An analysis of data gathered by a uniquely detailed survey of vegetation at sites across Europe may provide clues to the future state of the Earth’s climate.
Dutch scientist Henk Pelgrum has just finished a two-year stint as an Agency Research Fellow. Attached to the ESA Earth Science Division, Henk has been studying the results from DAISEX (Digital Airborne Imaging Spectrometer Experiment). During the DAISEX campaign different sensors were flown over locations in Spain, France and Germany. One of the sensors, known as the HYMAP sensor, is able to record 128 different wavelengths simultaneously, ranging from the optical to the short-wave infrared. Henk said, “This data is used to determine different characteristics of land vegetation, such as chlorophyll content, leaf water content and canopy height. The amount of carbon stored in the plant matter is subsequently derived from these findings.”
Increasing our understanding of the way in which carbon is cycled between the land, ocean and atmosphere is important because carbon dioxide is the most important anthropogenic greenhouse gas. It has been estimated that the amount of carbon dioxide in the atmosphere has increased by one third since the Industrial Revolution due to the burning of fossil fuels. As a result the strengthening of the greenhouse effect has become a pressing environment issue. However, there is a gap in our knowledge – about half of the 1,600 million tonnes of carbon released annually through anthropogenic activity does not actually remain in the atmosphere as was once thought. Instead, it appears that it is either absorbed by the oceans or stored in vegetation, both of which can be considered as ‘carbon sinks’.
DAISEX has been able to analyse the variation of vegetation within different biomes and the resulting data has proved to be uniquely detailed and reliable. Henk has been looking into ways in which this valuable data can be applied to modelling future global climate change. The DAISEX flights have also served as a dry run for SPECTRA (Surface Processes and Ecosystem Changes Through Response Analysis), which is one of the strongest contenders for an ESA Earth Explorer mission. These missions are the cornerstones of ESA’s Living Planet Programme, dedicated to advancing our knowledge of the Earth. The aim of the SPECTRA mission is to study the role of terrestrial vegetation in the global carbon cycle and its response to climate variability under the increasing pressure of human activity.
Although Henk has now finished his Fellowship and is joining Water Watch, an Earth observation consultancy, the Agency will hopefully see him back in the future for further collaboration.