The Ethiopian goal is an eventual total of 4 billion trees. At 1000 trees per hectare, 4 million ha. But the Siberian fires have already consumed 27 million hectares of tiaga and tundra, so another 6 Ethiopian sized efforts are required just to keep even.
Most universities have an informal magazine, where their researchers are showcased to the general public by trained journalists. The journalist author of this article is curiously at odds with the scientist being showcased. Perhaps the readership of the magazine for the Technical University of Munich expects to hear the comforting fairy stories of the "Energiewende" revolution before the discomforting facts are dragged in. We are reminded that trees are "saviours in an era of climate change". Through their (holy) green leaves, they "transform the greenhouse gas into oxygen and biomass". We are told that the IPCC has discovered that Amazon rainforests absorb a quarter of the world's fossil emissions. Rather than offend the University's readers' faith in carbon sequestration, we are not told that most of it is soon released again by biological action.
On the other hand, the research by the ecologist researcher is saying quite the opposite. She explains that the trees are stressed by global warming (though cheered up by a dose of phosphorus) so their capacity to create biomass is decreasing. In consequence the enormous inventory of forest biomass is doomed to shrink as the return flow to the atmosphere exceeds photosynthesis. In the Amazon the decline may reach 100%, that is, a collapse where the rainforest is replaced by fire-ravaged savannah. It is ironic that the C4 photosynthesis of grasslands actually does respond to excess CO2, unlike the C3 photosynthesis of the forests they will replace.