The Geography of Climate Change

How Changes in Global Temperatures Could Affect Ecosystems

Feb 14, 2009

Ecosystems exist in large part due to the climate that occurs in a particular place on the planet. As the climate changes, how could ecosystems move and change?

Ecological change happens all of the time. However, as the world moves into an era of global temperature changes that will quite possibly be profound, will ecosystems be able to change and adapt? Or will the world of the future look very different?

How Could Climate Change Move Ecosystems?

Animals and plants are adapted to their environment. Each plant and animal has found a niche in its ecosystem, a place where it contributes to and is sustained by a web of other plants and animals. Scenarios about how climate change is happening and might happen in the future abound. No one knows how people will change their actions and exactly how the planet will react. However, there will be change.

For example, scientists at the Massachusetts Institute of Technology Center for Global Change Science Modeling Initiative have created maps of possible changes in global precipitation for climate change scenarios. While these are based on future "what if" situations, they pose very real possibilities for ecological change due to changes in precipitation. Temperature and precipitation are two factors that could greatly alter the nature and location of global ecosystems.

Subtle Changes in the Seasons Will Challenge Ecosystems

Almost imperceptibly, the seasons have been changing. The Chicago Tribune recently mentioned that the start of spring has moved two days earlier in the last 50 years. This may not seem like a large shift, but a whole succession of events happen during the seasons in a very specific order. If these events happen out of order, animals do not find the food that they need. For example, spring is coming so early in the far north that by the time female caribou come to eat the plants they need to feed their calves, these plants have gone to seed. The change in the seasons could cause animals to move to areas where they can meet their needs at the right time, adapt, or die.

Extreme Weather and Disease Events May Push Species to the Edge

Along with the subtle upward shift in global temperatures comes a change in the frequency of extreme weather events. For example, the David Suzuki Foundation states that in the boreal forests of Canada, forest fires have gone from 1 million to 3 million hectares in the last decade.

Additional movement of animal and plant diseases will also stress ecosystems. For example, the mountain pine beetle has been spreading in Western Canada, killing huge numbers of pine trees. Natural Resources Canada states that the beetle can be controlled by long, deep and cold winters. However, these winters are decreasing. For animals and plants already living on the edge, these extreme events may push them into smaller and smaller ranges where they can survive.

How will species move as the climate changes? Can they move? Species and ecosystem survival in times of change depend on the nature of the change as well as species characteristics. Some species may have characteristics that help them survive.

The existance of ecological reserves and the ability of ecosystems to move within them is one of the most difficult questions related to ecological change in the face of global temperature shifts. In many places in the world, human impacts on local ecosystems have been profound. Areas do exist with trees, natural flowing water, native soil, and the associated host of plant and animal species that interconnect in ecological webs. However, as a changing climate makes it more challenging for plants and animals to survive, species may need to shift to the different parts of their historic territory. If the historic territory is covered with houses, it will be difficult for that species to survive.

Individuals, communities and government need to work together to ensure that animals, plants and ecosystems have places to go as the climate changes. Working to provide urban habitats for species as risk and protect wildlife corridors are two ways that people can conserve species in a changing climate.

The copyright of the article The Geography of Climate Change in Biogeography is owned by Tricia Edgar. Permission to republish The Geography of Climate Change in print or online must be granted by the author in writing.