Vanishing Forests: How Climate Change is Driving the Decline in Biodiversity - OPINION March 19, 2025

Vanishing Forests: How Climate Change is Driving the Decline in Biodiversity 

Dear Readers!

Forests, often called the "lungs of our planet," house more than 80% of terrestrial species, playing a critical role in maintaining global biodiversity. Nevertheless, they are under siege, facing a silent crisis not just from deforestation but from a far more insidious threat—climate change. Rising temperatures, erratic weather patterns, intensifying wildfires, and shifting rainfall cycles are transforming ecosystems at an alarming pace, pushing countless species to the brink of extinction.

According to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), nearly one million species face extinction in the coming decades, and forests are among the hardest-hit ecosystems. The World Resources Institute (WRI) warns that more than 10 million hectares of forest are lost annually, exacerbating biodiversity decline. As forests shrink and fragment, the delicate balance of their ecosystems unravels, threatening wildlife, indigenous communities, and the global climate itself.

But this crisis is more than just numbers. It is a reality unfolding globally, with visible and devastating consequences. From the heart of the Amazon to the snow-capped peaks of the Alps, from the mangroves of Southeast Asia to the wildfire-ravaged landscapes of California, climate change redefines what forests can sustain—and which species will survive.

So, how is climate change disrupting forest biodiversity? What are various threats that have risen multifolds due to climate change?  

Forests have always been dynamic ecosystems, adapting to environmental changes over millennia. However, the rapid pace of climate change has outstripped their natural resilience, causing disruptions at an unprecedented scale. Rising temperatures, erratic rainfall, wildfires, and invasive species are no longer isolated occurrences—they are reshaping entire forest ecosystems, threatening species survival and biodiversity stability. As these threats intensify, forests lose their ability to function as carbon sinks, protect watersheds, and provide refuge to countless species. Let us explore the significant ways climate change is dismantling forest biodiversity and altering the very fabric of these once-thriving ecosystems:

a. Rising Temperatures and Habitat Loss 

As global temperatures climb, forests are experiencing extreme heat stress, altering their ability to support diverse life forms. Many species, finely adapted to specific temperature ranges, are forced to migrate—if they can—or perish. One of the prominent examples is that of the Amazon Rainforest, the world's largest tropical rainforest, which has reached a dangerous tipping point. Once a carbon sink absorbs CO₂ from the atmosphere, parts emit more carbon than they store presently. A 2021 study in Nature Journal revealed that 30% of the Amazon's ability to absorb carbon dioxide has been lost, leading to drastic shifts in wildlife populations and increased tree mortality.

Another highlight is the Alpine Exodus, in the Swiss Alps, where rising temperatures push tree lines higher, but cold-adapted species such as the alpine ibex and rock ptarmigan have nowhere to go. Their shrinking habitat increases the risk of local extinction.

 b. Raging Wildfires and Mass Destruction 

We all know that extreme heat and prolonged droughts ignite an unprecedented wave of wildfires, leaving charred landscapes devoid of life. The flames destroy trees and entire ecosystems, leaving species with no refuge. One of the primary examples is that of Black Summer in Australia, where in 2020, Australian Bushfires burned 186,000 square kilometres of forest, causing the loss or displacement of an estimated 3 billion animals, including koalas, wombats, and wallabies. Many species pushed to the brink have not recovered.

Another noticeable destruction is from California's Burning Forests, where over the last five years, California has lost 6 million acres of forest to wildfires, with over 10,000 ancient giant sequoias perishing in the 2020 Castle Fire alone. These trees, some over 3,000 years old, are irreplaceable pillars of biodiversity.

 c. Disrupted Rainfall and Drought Stress 

It is a fact that forests thrive on stable precipitation cycles, but climate change is disrupting rainfall patterns, triggering extreme droughts in some areas and flooding in others. The Congo Basin, which is the world's second-largest rainforest, has experienced a 5% decline in annual rainfall over two decades, threatening iconic species like forest elephants, okapis, and lowland gorillas that rely on dense, water-rich environments.

There have been Dry Spells in the Amazon, which suffered one of its worst droughts in 2023, with historic low water levels disrupting the migration patterns of freshwater species such as the Amazon River dolphin and displacing Indigenous communities dependent on the forest's waterways.

 d. Invasive Pests and Deadly Diseases 

Climate change creates favourable conditions for invasive species, pests, and pathogens, wreaking havoc on native forests. One such stark reminder is the Bark Beetle Invasion in the North American pine forests, which are being decimated by bark beetles, whose populations have exploded due to warmer winters. Over 40 million acres of forests have been lost, weakening tree defences and making entire ecosystems more fire-prone.

Furthermore, Africa's Dying Trees, a study by the International Union for Conservation of Nature (IUCN), found that 40% of African tree species are now vulnerable to fungal and bacterial infections linked to climate-induced stress.

e. Vanishing Coastal and Mangrove Forests 

Mangrove forests serve as nurseries for marine species, natural flood barriers, and carbon storage hubs, yet they are rapidly disappearing due to rising sea levels and saltwater intrusion. There has been A Global Decline since 1980, as the planet has lost 20-35% of its mangrove forests, erasing critical habitat for fish and birds, exposing coastal communities to stronger storms, and accelerating biodiversity loss.

Additionally, the Sundarbans Mangrove Under Threat, home to the endangered Bengal tiger, faces an existential crisis. If global warming surpasses 2°C, scientists estimate that 70% of the Sundarbans could be underwater, displacing wildlife and human populations.

All such events have the Ripple Effects of Forest Biodiversity Loss. The loss of biodiversity within forests extends beyond their immediate surroundings, affecting:

• Pollination and Food Security – Declining bee, butterfly, and bird populations disrupt crop pollination, threatening global agriculture.

• Carbon Storage and Climate Stability – Deforested areas release stored carbon, worsening global warming.

• Indigenous Communities – More than 1.6 billion people depend on forests for sustenance and shelter; climate-driven forest loss is displacing many of them.

• Economic Losses – Forest-dependent industries, including timber, medicine, and eco-tourism, are losing over $200 billion annually due to biodiversity collapse.

Therefore, to conclude the entire discussion, there is an urgent need for action as the decline in forest biodiversity is an unfolding ecological disaster. Scientists predict that if temperatures rise beyond 1.5°C, over 30% of global forest species could face extinction by 2100.

We are already witnessing alarming signals, ranging from Amazon's weakening resilience to the crumbling mangrove forests of Asia, from the drying Congo Basin to the infernos of California.

However, there still lies hope since Global initiatives such as the Great Green Wall in Africa, which aims to restore 8,000 km of degraded land, show that large-scale restoration is possible. Enforcing zero-deforestation supply chains, implementing sustainable land management, and investing in climate-resilient forestry are vital steps toward reversing biodiversity loss.

Let us pledge to revive and restore our forests since the fate of the world's forests and the species within them is deeply tied to our collective actions. The time to act is now.

The question is no longer if forests will disappear but whether we will stop their decline before it is too late since:  

Protecting forests is not just an environmental cause; it is a fight for the survival of life on Earth. 

Till we meet again 

Dr Prachi Jain