Saudi Arabia, now a desert land with 95% arid terrain, was once a green paradise, say recent scientific studies. Research led by global teams using satellite maps, archaeology, and geology shows the Arabian Peninsula had grasslands, rivers, and large lakes during wetter times of Earth's Ice Age, called the Pleistocene Epoch. University of Oxford's Michael Petraglia said, "Innovative space shuttle technology has allowed the mapping of over 10,000 lakes across Arabia including the now barren Nafud desert." Discoveries of ancient elephants, hippos, and crocodiles fossils prove these water-rich environments existed. King Abdullah University of Science and Technology (KAUST) scientists found a lake in the Empty Quarter desert, once covering 1,100 square kilometres and 42 meters deep. This lake overflowed and carved a 150 km valley during the "Green Arabia" phase about 11,000 to 5,500 years ago. These wet periods varied across the peninsula, creating habitable corridors for early humans. Petraglia said such landscapes "facilitated the expansion of hunting, gathering, and pastoral groups into what is now a dry, barren desert." Prince Sultan bin Salman, head of Saudi's Tourism and National Heritage Commission, highlighted that early humans used Arabia as a migration route during these greener times. Stalagmite records from Saudi caves confirm lush conditions throughout the last eight million years, suggesting the vast desert regions like the Sahara and Thar Desert were once savannahs. Today, Saudi Arabia is fighting desertification with the Saudi Green Initiative. The kingdom pledged to plant 10 billion trees and rehabilitate nearly 75 million hectares. Already, by mid-2025, over 151 million trees were planted, aiming for 600 million by 2030, including major urban projects like Riyadh's plan for 7.5 million trees. The program uses drought-resistant trees, treated wastewater, smart irrigation, and drones for planting. This effort is part of the larger Middle East Green Initiative aiming to plant 50 billion trees. Can modern Saudi Arabia revive the echoes of its ancient green past? New science and bold action may turn the desert kingdom into a model for other dry nations fighting climate challenges.