Biodiversity & Climate Change
Climate change will have significant impacts on many aspects of biological diversity. These impacts include effects on ecosystems, component species and genetic diversity within species, and on ecological interactions. The implications of these impacts are significant for the long-term stability of the natural world and for the many benefits and services that humans derive from it. Because of the importance of these impacts and of climate change itself, there has been a great deal of recent research, which has added to the evidence base.
If one or more species is removed from the environment, it can harm the ecosystem. Introducing foreign or invasive species into a habitat can have similar results, as the invasive species can out-compete the native species for food or territory. If undiscovered or uninvestigated wildlife species disappear, it would disadvantage scientists trying to uncover new sources of inspiration. Biodiversity affects our food, medicine, and environmental well-being.
Dragonflies, bees and beetles pollinate many of the crops we rely on for food, as well as plants in natural ecosystems. One type of pollinator cannot do it all, hence the importance of biodiversity. Loss of habitat — for example, when humans convert meadows into parking lots or backyards — is reducing pollinator populations. If pollinators were to disappear entirely, we would lose over one-third of all crop production. This would reduce or eliminate the availability of foods like honey, chocolate, berries, nuts and coffee.
Biodiversity also provides ecosystem services or benefits to people. These benefits include hurricane storm surge protection, carbon sequestration, water filtration, fossil fuel generation, oxygen production and recreational opportunities. Without a myriad of unique ecosystems and their respective diverse plant and animal life, our quality of life may become threatened.
Changing temperature, precipitation patterns and increasing concentrations of atmospheric CO2 are likely to drive significant modifications in natural and modified forests. Climate change is increasing the vulnerability of many forests across the world through fire, insect infestations, drought, and disease outbreaks. Forests play an important role in absorbing and storing carbon dioxide, but the rate of uptake is projected to decline. However, forests also provide opportunities to reduce future climate change by capturing and storing carbon, as well as by providing resources for bioenergy production (the use of forest-derived plant-based materials for energy production). This is why it is crucial to stop deforestation and protect forests. While restoration and reforestation efforts are equally important, old forests have the capacity to absorb and store more carbon than newer forests.
Large-scale die-offs and wildfire disturbance events could potentially impact local and regional timber production, increase flooding and erosion risks, add to other changes in water budgets, and cause biogeochemical changes including levels of carbon storage and changes to the aesthetics of the landscape.
Check out Ecosia — an organization that restores forests through tree plantations that are sustainable.
There are a number of ways that climate change impacts wildlife. Increases in temperature and changes in precipitation can directly affect species depending on their physiology and tolerance to environmental changes. Climate change can also alter a species’ food supply or its reproductive timing, indirectly affecting its fitness. In the last few decades, natural scientists and conservationists have observed marked changes in the condition and distribution of wildlife on a global scale. These changes are occurring at rates that are higher than expected for a species, habitat, or ecosystem, and such observations are providing real, clear evidence that climate change is already having a devastating impact on our environment. Understanding these interactions is an important step in developing management strategies to help species survive the changing climate. The health of wildlife, people, and the habitats they rely on are all interconnected. Effects on one part of an ecosystem affect other parts over time, and climate change is already impacting many species of native wildlife around the world.
To conserve wildlife and habitats in a changing climate, we must use the best available science to understand the specific threats that wildlife and ecosystems are expected to face — sea-level rise, higher temperatures, and more frequent storms and droughts–and develop measures to mitigate these impacts or provide opportunities for species and habitats to shift in response.
Here is an interesting field guide to climate change impacts to wildlife across North America developed by Defenders of Wildlife.
Climate and the Ocean, from IUCN’s Ocean and Climate Change Brief
At the front line of climate change, the ocean, the coastlines and coastal communities are being disproportionately impacted by increasing carbon dioxide (CO2) and other greenhouse gas (GHG) emissions from human activities. Atmospheric warming is leading to the melting of inland glaciers and ice, causing rising sea levels with significant impacts on shorelines (coastal erosion, saltwater intrusion, habitat destruction) and coastal human settlements. CO2 emissions are also making the ocean more acidic, making many marine species and ecosystems increasingly vulnerable. Ocean acidification reduces the ability of marine organisms, such as corals, plankton and shellfish, to build their shells and skeletal structures. It also exacerbates existing physiological stresses (such as impeded respiration and reproduction) and reduces growth and survival rates during the early life stages of some species.
The ocean and coasts provide critical ecosystem services such as carbon storage, oxygen generation, food and income generation. Coastal ecosystems like mangroves, salt marshes and seagrasses play a vital role in carbon storage and sequestration. Per unit of area, they sequester carbon faster and far more efficiently than terrestrial forests. When these ecosystems are degraded, lost or converted, massive amounts of CO2 — an estimated 0.15–1.02 billion tons every year — are released into the atmosphere or ocean, accounting for up to 19% of global carbon emissions from deforestation. The ecosystem services such as flood and storm protection that they provide are also lost.
The impacts of ocean warming and acidification on coastal and marine species and ecosystems are already observable. For example, the current amount of CO2 in the atmosphere is already too high for coral reefs to thrive, putting at risk food provision, flood protection and other services corals provide. Moreover, increased GHG emissions exacerbate the impact of already existing stressors on coastal and marine environments from land-based activities (e.g. urban discharges, agricultural runoff and plastic waste) and the ongoing, unsustainable exploitation of these systems (e.g. overfishing, deep-sea mining and coastal development). These cumulative impacts weaken the ability of the ocean and coasts to continue to perform critical ecosystem services.
The degradation of coastal and marine ecosystems threatens the physical, economic and food security of coastal communities — around 40% of the world population. Local fishers, indigenous and other coastal communities, international business organizations and the tourism industry are already seeing the effects of climate change particularly in Small Island Developing States (SIDS) and many of the Least Developed Countries (LDCs). Weakened or even lost ecosystems increase human vulnerability in the face of climate change and undermine the ability of countries to implement climate change adaptation and disaster risk reduction measures, including those provided for in Nationally Determined Contributions (NDCs) under the Paris Agreement on climate change.
