The five systems of Earth: geosphere, biosphere, cryosphere, hydrosphere, and atmosphere interact to produce the earthly known environment. Global forests play fundamental biophysical, biogeochemical, hydrological, economic and cultural roles in the Earth systems. But the most important fact is that all forests have a central role in the local and global carbon and water cycles with feedbacks into the climate system. World’s forests cover 31% of the global land area. The Global Forest Resources Assessment (2020) revealed that forests covered a total of 4.06 billion hectares of Earth’s land and estimated that 50% of the forest area is relatively intact. Additionally, global forests account for 75% of the gross primary production of the Earth’s biosphere, and contain 80% of the Earth’s plant biomass. Forests on Earth are concentrated in 10 countries that have the largest cover of forested areas. 50% of the world’s forests are found in only 5 countries (Russian Federation, Brazil, Canada, USA and China) and a total 66% of forests are found in 10 countries. Tropical forests are home to some of the richest and most diverse ecosystems on the planet with over 50% of the world’s species reside in tropical forests.  All scientific studies showed that the restoration of global forests and planting more trees can be one of the most effective strategies for climate change mitigation and the preservation of biodiversity. But some scientists are sceptical  that future plans to triple the area of global forests to meet the goals by absorbing excess CO2 are very ambitious. Keeping global warming below 1.5 °C (up to 2050) to avoid dangerous climate changes requires the removal of vast amounts of CO2 from the atmosphere, as well as drastic cuts in greenhouse gas emissions.  In the last decade the United UN Environment Programme (UNEP) started the Billion Tree Program which aims to improve quality of life and limit environmental degradation through the multiple benefits provided by planting large number of new trees on a massive scale. Some scientists are skeptical for the large scale planting of trees at a period that  global warming is increasing