Climate Change and Biodiversity Loss
 |
| Coral bleaching is one of the signs of biodiversity loss |
The evidence of a changing climate is compelling and diverse, which affects every region of the globe and impacts numerous aspects of daily life. From severe weather events and escalating sea levels to transforming ecosystems and health challenges, humans are suffering. The repercussions of climate change are increasingly intense and, unfortunately, unavoidable. Gaining insight into these developments is essential for formulating effective strategies for mitigation and adaptation to this crisis, which will be examined in the following chapters.
Biodiversity Hotspots Under Threat
Biodiverse hotspots around the globe are experiencing extra heat due to climate change. Biodiversity hotspots are regions characterized by remarkably high levels of species richness and endemism, yet they face significant threats from human activities. Climate change amplifies these risks by altering the environmental conditions essential for the survival of these unique ecosystems.
Often referred to as the "lungs of the Earth," the Amazon is vital for the Earth's carbon cycling and climate regulation. Increasing temperatures and shifts in precipitation patterns heighten tree mortality and increase the risk of forest dieback. A savanna-like ecosystem could be the resulting form of the Amazon when its biodiverse rainforest transforms due to climate change. Such a change would release billions of tons of carbon dioxide into the atmosphere, further accelerating global warming (Malhi et al., 2008), thus intensifying the impacts of climate change.
Located in Southeast Asia and the Pacific, the Coral Triangle boasts the highest marine biodiversity on the watery face of the planet. However, coral reefs in this region suffer severe bleaching due to ocean warming, with certain areas experiencing a loss of up to 50% of coral cover in recent decades (Hoegh-Guldberg et al., 2018).
Escalating temperatures in the Arctic lead to permafrost melting and disrupting habitats crucial for species such as polar bears, Arctic foxes, and migratory birds. The reduction of ice and snow cover diminishes hunting grounds and alters prey availability, which negatively affects the survival of these iconic species (Post et al., 2019). Another study by Kissling et al. (2021) reports that the warming Arctic is leading to shifts in species distributions, impacting predator-prey dynamics. Polar bears are experiencing decreased access to hunting areas as sea ice diminishes, which can lead to decreased body condition and increased mortality rates (Kissling et al., 2021). Additionally, a review by Ganter et al. (2020) indicates that migratory birds face altered migration patterns and habitat availability due to changing climatic conditions, potentially resulting in population declines (Ganter et al., 2020).
Species Extinction and Population Declines
The extreme impacts of climate change are intensifying the extinction rates of both plants and animals, often in conjunction with additional stressors such as habitat loss, pollution, and overexploitation for consumption and business purposes. According to recent studies, scientists estimate that as many as one million species are at risk of extinction due to climate-related impacts (IPBES, 2019).
Shifts in Habitats
As global temperatures rise, numerous species migrate to higher altitudes or latitudes in search of more suitable climates. For instance, certain butterfly species in Europe have shifted their ranges northward by over 100 kilometers in recent decades (Parmesan & Yohe, 2003). However, not all species can adapt or relocate quickly enough to escape these rapidly changing conditions.
Ocean Acidification and Marine Species
The increasing absorption of excess atmospheric CO₂ by the oceans leads to acidification. Ocean acidity has increased by about 25% since the Industrial Revolution. Laboratory studies suggest this could affect species sensitive to acidity, harm organisms with carbonate shells, diminish the availability of calcium carbonate essential for developing shell-forming organisms such as corals, mollusks, and some plankton species, and impact higher-level organisms that depend on these species for food. However, the precise effects on ecosystems are still uncertain (EPA, 2024).
Keystone species, which are responsible for maintaining ecological balance, are particularly susceptible to the impacts of climate change. For example, the decline of sea otters due to warming waters has detrimental effects on kelp forests, as unchecked sea urchin populations can consume kelp beds, ultimately leading to ecosystem collapse (Estes et al., 2011).
Over the past 50 years (from 1970 to 2020), the average size of monitored wildlife populations has dramatically declined by 73%. The most significant decreases have been observed in Latin America and the Caribbean, where the decline is 95%, followed by Africa at 76% and the Asia-Pacific region at 60%. Freshwater ecosystems have also been severely affected, experiencing an 85% decline, according to the World Wildlife Fund for Nature's Living Planet Report 2024 (WWF, 2024).
Ecosystem Services at Risk ($577 billion annually)
Ecosystems provide services to human life and economic activities in varied ways. The services that ecosystems provide are essential to human life and their economic activities. However, due to the disruptions to these vital services, global food security, water availability, and disaster resilience for humans suffer serious negative consequences.
Many crops depend on insects, such as bees, for pollination. Rising temperatures and changes in flowering patterns disrupt the synchrony between pollinators and plants, reducing crop yields and threatening humans and animals. Research indicates that the decline in pollinators could lead to global economic losses of up to $577 billion annually (IPBES, 2016).
Forests and wetlands serve as natural reservoirs, regulating water flow and reducing the risk of floods and droughts. Deforestation, wetland degradation, and other related climate-induced changes compromise their essential functions in water regulation, leading to water scarcity and an increased risk of flooding.
Forests, grasslands, oceans, and relevant ecosystems are vital carbon sinks that absorb CO₂ from the atmosphere. Unfortunately, the various impacts of climate change diminish their natural capacity to sequester carbon in the atmosphere. For example, in the Amazon rainforest, certain areas emit more CO₂ than they can absorb (Phillips et al., 2009). In addition, biodiversity loss in these ecosystems can worsen their ability to capture carbon. The existence of diverse plant and animal species contributes to the resilience and functionality of various sensitive ecosystems, which serve as carbon storage.
Case Studies of Vulnerable Species and Habitats
Real-world examples vividly illustrate the serious and often devastating impact of climate change on biodiversity.
Considered the iconic residents of the Arctic, the polar bears directly suffer the impacts of climate change. Polar bears heavily rely on the existence of sea ice as their major platform for hunting seals, constituting their primary food source. However, due to climate change, this essential ice is melting at an alarming rate—forming later in the fall and breaking up earlier in the spring. As a result, polar bears are forced into more extended fasting periods, exacerbating their struggles to find sustenance. This extended scarcity not only diminishes their physical condition but also significantly hampers their reproductive success, setting off a worrying decline in their population (Stirling & Derocher, 2012).
The Great Barrier Reef, the most extensive and most intricate coral reef system on the planet, is undergoing dramatic changes linked to rising sea temperatures driven by climate change. Since 1998, the reef has faced five catastrophic mass bleaching events, which have crumbled its vibrant ecosystem. The ripple effects occur throughout the marine environment, with live coral cover plummeting by more than 50%. The decline impacts the reef's stunning biodiversity and critical role in supporting local fisheries and attracting tourists, threatening both ecological balance and economic stability in the region (Hughes et al., 2017).
Mountain Gorillas in Africa
In the lush African mountainous forests, the mountain gorillas are already teetering on the brink of extinction due to habitat destruction and poaching, while facing the brunt of additional adversities spawned by climate change. Rising temperatures and shifting rainfall patterns are disrupting the delicate balance of the African ecosystem, such as a reduction in bamboo, a fundamental food source for these magnificent primates. The diminishing number of mountain gorillas due to the scarcer bamboo highlights the interconnectedness of climate health and species existence (Lehman et al., 2020).
The Cascading Consequences of Biodiversity Loss
The loss of biodiversity leads to various cascading effects that disrupt ecosystems and impact human well-being. The following are significant consequences associated with biodiversity loss.
Ecosystem Instability
Ecosystems can become unstable as climate change's cascading effects reduce biodiversity, diminish resilience, and make them more susceptible to multiple issues, such as pests, diseases, and the increasingly severe impacts of climate change. This instability can lead to a breakdown of ecological processes that support life, such as pollination, nutrient cycling, and water filtration, ultimately resulting in less productive environments struggling to recover from environmental stressors.
Food Security
The impacts of climate change existentially threaten food security. As ecosystems are extremely compromised, the consequences for food security become increasingly gloomy. Declining fish stocks in oceans and freshwater bodies, agricultural crop failures, and diminished livestock productivity are direct repercussions of destabilized ecosystems. The risks to a declining food supply chain logically increase food scarcity and price hikes and could ultimately worsen hunger and malnutrition, particularly in the populations in countries and regions affected mainly by climate change.
In 2023, approximately 2.33 billion people worldwide faced moderate or severe food insecurity, with over 864 million experiencing severe food insecurity. The lack of economic access to healthy diets affects over one-third of the global population, with 2.8 billion unable to afford a healthy diet in 2022, predominantly in low-income countries (71.5%) compared to high-income countries (6.3%). The report emphasizes that food insecurity and malnutrition are worsening due to persistent food price inflation, conflict, climate change, economic downturns, unaffordable healthy diets, unhealthy food environments, and increasing inequality, collectively amplifying their impacts (WHO, 2024).
Economic and Cultural Losses
The losses that biodiversity brings extend into economic and financial life, seriously affecting food producers, including agriculture, forestry, and fisheries, among other crucial resources. The decline in several food products is tantamount to lesser harvests and economic instability, primarily for farming and fishing communities. This decline will directly affect the food sector and threaten producers, markets, and consumers.
In addition, the decline and loss of biodiversity negatively impact the cultural and spiritual values of indigenous communities living in the natural world for generations. Therefore, losing connections with nature due to biodiversity loss could lead to social and cultural disintegration should their traditions, practices, and ancestral treasures are affected by biodiversity loss.
Read the complete contents here.
