  Earth system tipping elements have been predominantly investigated for their
potential to trigger \textit{negative} ecological, climatic, and societal
shifts. Yet, an overlooked but seminal avenue exists in the form of
\textit{positive} tipping phenomena, whose underlying mechanisms and benefits
remain largely underexplored. To bridge this gap, our research introduces a
fundamental percolation-based framework to assess the criticality and
resilience of planetary terrestrial vegetation systems. Leveraging
high-resolution satellite data, we focus on greening-induced positive tipping
dynamics driven by global warming. We feature the Qinghai-Tibetan Plateau (QTP)
and the Sahel region as contrasting yet analogous case studies. Our analysis
uncovers an intriguing phenomenon where vegetation fragmentation aligns with a
percolation threshold, exhibiting a scale-invariant pattern characterized by
nearly perfect power laws with three critical exponents. Remarkably, contrary
to conventional destructive tipping elements, these regions act as favorable
tipping elements, transitioning from fragmented to cohesive vegetation patterns
due to anthropogenic climate change and afforestation efforts. Furthermore, we
propose an \textit{optimal resilience enhancement model} to reinforce
vegetation robustness while minimizing socio-economic costs. This study
provides valuable insights into the favorable aspects of tipping elements under
climate change and offers effective strategies for enhancing ecological
resilience against environmental threats.
