- December 7, 2008
- Posted by: EARSC
- Category: EARSC News
At the United Nations Climate Change Conference in Poznań, 1-12 December 2008, more than 200 countries are about to commit to new levels of carbon dioxide reductions and emission targets, but how do we really know that they will abide by what they pledge. Maybe one of ESA’s (European Space Agency) next generation earth observation satellites will be able to help monitor those commitments.
The ESA A-SCOPE (Advanced Space Carbon and Climate Observation of Planet Earth) spacecraft is a state-of-the-art carbon dioxide measuring satellite mission that will use a pulsed laser and LIDAR (Light Detection and Ranging) techniques to measure carbon dioxide over the entire planet. The ESA spacecraft will also provide information on tree canopy topography, atmospheric aerosol and cloud layer measurements, greatly improving weather models as well as providing invaluable insight into how carbon dioxide is forming and mixing so improving the climate change models being worked on around the world.
A-SCOPE will be able to map global carbon dioxide levels around the entire planet on a repetitive basis to help evaluate how carbon dioxide mixes with the atmosphere, ocean and other environments, both urban and rural.
A-SCOPE has just completed an internal assessment before going to the January 2009 ESA User Consultation Meeting that will choose from one of six possible missions (A-SCOPE, BIOMASS, CoReH20, FLEX, PREMIER and TRAQ). The launch date would be sometime in 2016.
Atmospheric carbon dioxide has increased by more than 30% since the start of the industrial revolution and is the main reason for global temperature increase. Half of the human related carbon emissions are still in the atmosphere while the rest has been absorbed by the land and mostly by the oceans. Knowing how the carbon dioxide re-distributes itself between air, land and ocean will lead to a better understanding of just how much more carbon dioxide can be absorbed, and where that carbon dioxide is mostly coming from around the planet.
The main instrument onboard A-SCOPE will use two short laser pulses of similar wavelengths that are fired at the planet, one pulse is absorbed by the carbon dioxide molecules, while the other is not. Comparing the returned laser reflection of both pulses will allow engineers and scientists to calculate how much carbon dioxide is in the path of the laser. The returned laser signal is also influenced by the reflection from the ground and this was an area of ambiguity, one that required some prior testing to prove the concept.
These advanced tests have just been completed and were comprised of airborne tests, called Reflex, done by the Institute for Atmospheric Physics at the German Aerospace Centre (DLR) to quantify the ground reflectivity. Over 500,000 measurements were made over all of Europe including open ocean, forest, mountains, different agricultural land-types and other typology. It was highly successful, even working very well over the Baltic and Mediterranean seas and shows that the A-SCOPE concept will function from space.
It will be great to have such a spacecraft in orbit, updating the carbon dioxide measurements, helping refine global change models and perhaps even ensuring countries will stick to their green house gas emissions targets. Perhaps A-SCOPE should be renamed Carbon-Cop Satellite and each country would get fined for not meeting their greenhouse gas targets. Now that would truly be worth having – a carbon monitoring eye-in-the-sky.
There is a carbon cost to everything, including building and launching A-SCOPE but it is likely that the information from the satellite will far outweigh the carbon cost of designing, building and launching the satellite.
BQ. Trevor Williams is a University of Victoria Mechanical Engineering PhD candidate specialising in renewable energy, power grid modelling and plug-in hybrid electric vehicles. He has a bachelors in Aeronautical Engineering, a Masters in Management Science and over 23 years international experience in the space industry, having worked on Earth observation and telecommunications satellites.
