Lennard de Klerk (1973) is lead author of the Initiative on GHG accounting of War and co-owner of Irota EcoLodge, the first, and so far only climate-neutral holiday resort in Central Europe. After the Russia’s full-scale invasion of Ukraine in February 2022, he brought together to group of experts to estimate the damage done to the climate, i.e. calculate additional GHG emissions that can be attributed to the war. In cooperation with the Ministry of Environmental Protection and Natural Resources of Ukraine, three assessments were presented at the UN Climate Change conferences in Sharm-el-Sheikh, Bonn and Dubai.