Green isn't always recovery: Sometimes, it's a warning of danger ahead

It is a peculiar and jarring sight: The Sahara, that unforgiving sea of sand, is boasting blue lagoons and carpet of green; the Thar is becoming wetter; and Antarctica, an ancient expanse of ice and rock, is sprouting moss and algae on its edges.

It’s not a mirage, but a reminder that the climate is changing in ways more complex than just rising temperatures. Precipitation patterns are shifting, turning deserts into sporadic green oases and upending fragile ecological balances. Should we celebrate this green renaissance, or does it serve as a warning of something more ominous?

According to a study, The Greening of the Sahara: Past Changes and Future Implications: “In recent decades, the Sahel region, south of the Sahara Desert, has experienced a significant wettening and re-greening after the dry decades of the 1970s and 1980s.” It further said that in the future, the Sahara and Sahelian regions “could experience more rainfall than today as a result of climate change”. Satellite images captured in September showed vegetation sprouting in pockets across the Sahara, triggered by an extratropical cyclone that drenched northwestern Africa.

The Thar is witnessing a similar transformation, too. Traditionally, monsoon in India leaves the eastern, verdant regions drenched, while the western border regions stay parched. But this predictable pattern is being disrupted. Climate change is causing the monsoon to push further west, spilling over into the Thar, which is greening faster than anticipated. A study published in Earth’s Future suggests that within a century, the Thar could cease to exist as a desert altogether. Data from the India Meteorological Department shows that Rajasthan has received 19 per cent more rainfall than normal between 2005 and 2024 during the monsoon season.

These changes are reminiscent of a time when both Sahara and Thar were fertile landscapes. Thousands of years ago, the Sahara was not the vast desert we recognise today, but a lush savannah teeming with life. Known as the African Humid Period, this era lasted from 14,000 to 5,000 years ago, a time when lakes, rivers, and grasslands sprawled across the region, supporting everything from crocodiles to elephants. In India, the Thar once had rivers like the Sarasvati flowing through it, supporting a wetter, more diverse ecosystem.

Even more alarming is the greening of Antarctica, the driest place on Earth, with some regions having gone without significant precipitation for up to two million years. According to a study in Nature Geoscience, vegetation in Antarctica has grown from a mere 2.84 sqkm in 1986 to 37.03 sqkm in 2021, spurred by rapidly rising temperatures and melting glaciers that expose once-buried soil. The greening of our planet raises important questions: If these trends continue, what will the Earth look like in a century? Will once-barren deserts become lush forests? Will the polar ice caps melt entirely? The answer to these questions are uncertain, but the potential consequences are dire.

One concept critical to understanding this shift is albedo, the measure of a surface’s ability to reflect sunlight. Deserts, with their pale, sandy surfaces, reflect much of the sun’s energy back into space. Similarly, Antarctica’s snow-covered terrain has an exceptionally high albedo, bouncing away up to 80 per cent of sunlight. This reflection helps keep these regions, and the planet, cooler. But when deserts begin to turn green, or when ice melts to reveal darker soil or rock, this albedo effect diminishes. Plants, which are darker than sand, absorb more sunlight, warming up the environment.

The greening of our planet, driven by human-induced climate change, is a complex phenomenon. In the late 1700s, carbon dioxide levels in the atmosphere were about 280 parts per million (ppm). Today, that number has ballooned to 420 ppm. If current trends continue, we could surpass 600 ppm by the end of the century. This accumulation of CO2 traps heat in the atmosphere, altering not just temperatures but also the global currents that determine where rain falls — and where drought prevails.

Scientists agree that cutting CO2 emissions and investing in carbon capture technologies are essential to curbing this crisis. International cooperation, particularly through frameworks like the Paris Agreement, remains our best hope to limit global warming to 2°C above pre-industrial levels. But time is running out, and current policies are falling short of the required ambition.

So, what do we make of these green deserts and melting polar edges? These are not signs of nature healing but signals of a planet under pressure.

Green is not always a sign of recovery. Sometimes, it’s a warning.