Tracking vegetation biomass change plays a crucial role in understanding the carbon cycle. And quantifying the global carbon cycle is essential for monitoring the numerous changes affecting our planet – especially those arising from the burning of fossil fuel and land-use change. This is why, as part of its Climate Change Initiative, the European Space Agency (ESA) has been actively researching vegetation biomass changes around the world.
Today, ESA has released a series of new maps that provide a global view of the above-ground biomass distribution and spatial density over three separate years – 2010, 2017, and 2018. (The 2020 map is currently under construction.)
These maps, provided at a 100 m resolution, have been created using a combination of satellite data from the Copernicus Sentinel-1 mission, Envisat’s ASAR instrument, and JAXA’s Advanced Land Observing Satellite, along with additional inputs from other Earth Observation sources.
The work, however, is far from finished. You cannot quantify the biomass changes over the last decade simply by subtracting the current maps. Since the data has been captured by sensors of different generations under different missions, the issue of temporal consistency between the different years still needs to be addressed.
For this, the research team is actively working on integrating additional low geometric resolution data streams into its algorithms. The new data could include the L-band vegetation optical depth from ESA’s Soil Moisture and Ocean Salinity satellite as well as scatterometer data from Eumetsat’s Metop satellite.
According to the team’s science leader, Shaun Quegan, “Combining these new data is anticipated to increase the consistency of these high-resolution maps, and move a step closer towards tracking changes and direct estimation of gross gains and losses of above-ground biomass at scale.”
Then again, vegetation biomass is a crucial ecological variable for understanding the evolution and potential future changes of the climate system, on a local, regional, and even global scale. And even in their current form, the maps could still allow scientists to undertake trend analyses, such as understanding the impact of regional climate phenomena such as El Niño on biomass dynamics.
Interestingly, ESA plans to launch a new Earth Explorer Biomass mission in 2022. This mission is being designed to provide, for the first time from space, P-band synthetic aperture radar (SAR) measurements to determine the amount of biomass and carbon stored in forests. The mission will also have an experimental ‘tomographic’ phase that would provide 3D views of the earth’s forests.