The global extent of grasslands is declining significantly because of climate change . In temperate and boreal zones, where about half of tree lines are shifting, they are overwhelmingly expanding poleward and upward, with an accompanying loss of montane and boreal grassland  whereas tropical tree lines have been generally stable  . The Eurasian steppes experienced a 1% increase in woody cover per decade since 2000  and inner Mongolian grasslands in China experienced broad encroachment as well . Climatic drivers of woody expansion in temperature-limited grasslands, particularly alpine grasslands, are most frequently attributed to warming  , an increase in water and nutrient availability from thawing permafrost   and rising CO2  . Interactions of LULCCs such as land abandonment, grazing management shifts and fire suppression with climate change are contributing factors 
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report