New advances in 2-μm high-power dual-frequency single-mode Q-switched Ho:YLF laser for dial and IPDA application

In the absence of climate change policies, the fossil fuel emissions are projected to increase in the next decades. Depending on how the current carbon sinks change in the future, the atmospheric CO₂ concentration is predicted to be between 700-1000 ppmv by 2100, and global mean surface temperature between 1.1-6.4°C, with related changes in sea-level, extreme events and ecosystem drifts. Keeping the atmospheric CO₂ concentration at a level that prevents dangerous interference with the climate system poses an unprecedent but necessary challenge to humanity. Beyond this point, global climate change would be very difficult and costly to deal with. There are two main approaches that are currently analysed: (1) to reduce emissions; (2) to capture CO₂ and store it, i.e. sequestration. For these two ways, some monitoring at different scales ultimately from space would be needed. Lidar remote sensing is a powerful technique that enables measurements at various space and time resolution.