Restoring Large Mammal Species Can Help Climate Change Adaptation and Mitigation

When it comes to climate change, we typically think of solutions focused on restoring vegetation to accelerate mitigation and boost the rate of adaptation to the changing climate. However, a new study explains how the restoration of large mammal species can help in climate change adaptation and mitigation. This is just one of many theories of climate change adaptation that may have an impact.

Here’s what you need to know about the study’s findings:

1. The study explains how the restoration of large mammals can contribute to localized climate change adaptation. (more…)

2. The study explains how the restoration of large mammals contributes to climate change mitigation through three factors: carbon stocks, albedo effects, and fire regime control. (more…)

Background Information: What is Climate Change Adaptation?

Full Research:  The role of large wild animals in climate change mitigation and adaptation

Climate change adaptation through the restoration of large mammals to ecosystems 

When animals cause changes to the structure and diversity of terrestrial plants, it’s possible that the locally observed microclimate can shift as well, which impacts climate change adaptation. Large animal species can help with climate adaptation in the following ways:

• Animals are also called the “natural gardeners of the Earth”. With their help, vegetation in particular ecosystems can flourish. For example, when large herbivores eat fruits and plants, they can carry and plant the seeds in different areas through their deposits. This increases habitat diversity and biodiversity, which allows the ecosystem to become more capable of adapting to a changing climate. 

• Large animals can also “filter” or control the species of plants that thrive in a particular area. For example, if large herbivores are restored in tundra biomes, they can help prevent the growing population of plants that are already climate-adapted, such as woody shrubs. This will provide a chance for other plant species like ground flowering plants and grasses to thrive. This ultimately helps create a more biodiverse, and thus more resilient, ecosystem.

• Plant grazing and large herbivore trampling in a localized area can modify the local microclimate, influencing climate change adaptations. The grazing and trampling of big herbivore animals, for example, can alter the surface roughness of the soil. This will have an effect on the heat or water vapor from the ground, which can enhance evapotranspiration and the water cycle in the area. 
• In marine ecosystems, large mammals such as whales can also help in climate change adaptation. For example, whale deposits provide nutrients for phytoplankton to thrive. When phytoplankton flourish, they contribute to seed clouds, which increase precipitation rates and can help alleviate drought and other problems caused by a changing climate.

Large mammals contribute to climate change mitigation

Researchers found three ways that large mammals can help to mitigate climate change: increasing carbon stocks, shifting albedo effects, and changing fire regimes. 

How large mammals help increase soil carbon stocks (carbon sequestration in soil)

• When large herbivores are present in an area, they increase the fertilization of the soil through their fecal deposits. Herbivores also help distribute seeds by moving to new areas to eat and leaving seeds in their deposits. These natural actions can help in improving the vegetation and soil health of the area, which means more CO₂ can be captured.
• In Tundra biomes, the grazing of large herbivores helps keep the surface ground exposed to the cold wind, which can preserve the permafrost or the ground that has been frozen for at least 2 years. This preserves the soil carbon trapped below the frozen ground.

• The presence of more whales in the ocean can cause phytoplankton blooms due to the nutrients from their deposits. Because phytoplankton collects 37 billion tons of CO₂ every year, this has a significant influence on carbon capture from the atmosphere.

How large mammals help maintain the albedo effect

• The albedo effect, or the ability of any surface to reflect solar energy (rather than absorbing energy and causing warming), can be maintained by large mammals. For example, the presence of large herbivores in arctic biomes aids in the preservation of the ice sheet by limiting the amount of woody surface cover or bushes that absorb heat. Herbivores expose the ground through grazing and trampling, allowing either a snowy surface or a grass field to function as a high albedo surface (one that reflects higher levels of solar energy and reduces warming).

• As previously stated, phytoplankton blooms generated by whale presence and deposits can also offer an albedo effect through cloud seeding (a process that generates rain). Dense clouds that hold water can reflect solar radiation in the atmosphere.

How large mammals help against fire regime

• Large mammals help to keep fire regimes, the typical patterns, and impacts of fire in a specific ecosystem, under control. For example, grazing by large herbivores trims and lowers excessive grasses that extend into shrub areas and might become wildfire connectors. Large mammals’ trampling and diggings in the soil generate trails that serve as fire breaks. As climate change increases the frequency of wildfires, the introduction of large mammals may help reduce the spread of wildfires, thus acting as an important method of climate change adaptation.

Sources: 

“The role of large wild animals in climate change mitigation and adaptation.” Current Biology, February 28, 2022. https://www.cell.com/current-biology/fulltext/S0960-9822(22)00101-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982222001014%3Fshowall%3Dtrue

When it comes to climate change, we typically think of solutions focused on restoring vegetation to accelerate mitigation and boost the rate of adaptation to the changing climate. However, a new study explains how the restoration of large mammal species can help in climate change adaptation and mitigation. This is just one of many theories of…