Effects to Species
As with any shift in the natural environment, climate change may cause species’ reductions or increases in range, breeding success, and total population size.
There is evidence that some species’ ranges have already shifted poleward or toward higher elevations as temperatures rose in the 20th century and these trends are continuing. This includes warm-adapted species whose ranges are expanding, and cold-adapted species whose ranges are contracting. Species with narrow ranges of temperature tolerances and less mobile species will likely have greater difficulty adapting to climate change.
Potential effects to fish and wildlife
- Impacts on wildlife physiology – For example, wildlife and the plants that sustain them could be greatly affected if they require certain temperatures to initiate growth or development, or to allow the processing of nutrients.
- Alteration of habitat characteristics – For example, ocean temperature and ocean acidification affects the ability of corals and other species to survive. Another example is the wind-driven ocean upwelling and mixing processes along the Pacific Northwest coast that are particularly important to productive marine ecosystems that support diverse marine life, major fisheries and seabirds.
- Alteration of species’ phenology– For example, temperature and other climate-driven factors can trigger changes in the timing of bird migration.
- “De-coupling” of wildlife relationships with key host or food plants – If seasonality changes as a result of global climate change, plant-animal processes such as pollination, seed dispersal and predator-prey relationships might be pushed “out of phase.”
- Species that cannot migrate will suffer the most. For example, plants, amphibians, mollusks, and coral reefs are more vulnerable to changing conditions that may affect their ability to survive, grow and reproduce.
