Unit 5: Climate Change Models Now and in the Future

Over the next century, plants and animals on land in BC might be in for a wild and ultimately devastating ride.  Warming temperatures, changing precipitation patterns, and extreme weather and climate events are likely to increase at a rate and magnitude not seen in more than 65 million years.  Global surface temperatures have risen about twice as fast over land as they have over the ocean, a trend likely to continue into the next century.  Based on current emissions trajectories, temperatures are projected to rise as much as 90 F over much of the Earth’s land.  The last time that the Earth warmed that much was around 55 million years ago, and it did so over a period of 10,000 years.  The projected change over the next century provides a small window in which life on Earth, including humans, will need to adapt to a similar change in temperatures.

The global climatic system is a series of connections between the atmosphere, the hydrosphere, the lithosphere, the biosphere and the sociosphere – us humans.  This global climatic system has been disrupted through huge impacts by humans, and is no longer in equilibrium.  This dis-equilibrium is now causing the extreme weather and climate events that are the subject of evening news stories around the globe.  For example, in the past 6 months in British Columbia, we have experienced the driest November on record, the wettest January on record, the fifth driest March on record and the driest April on record.  Ecosystems and the species that compose them are now subjected to dramatic swings away from ‘normal’ climatic conditions and are in the process of adaptation.  The changing climatic conditions will favour some plant and animal species and discourage others; some plant and animal species will be able to expand and occupy newly favourable habitats, while others will not have that ability, and may disappear.

The relationship between ecosystems and climate in BC is a complicated one, because BC has the highest level of ecological biodiversity in the country.  The climate models that are being developed for the province cannot easily predict the impacts of changing climatic conditions on the wide range of biodiversity here.  How can citizens respond to this complexity in a productive and positive way at the local level?

By gaining a basic understanding of ecological restoration principles, of ecological mitigation and of ecological adaptation, citizens can learn important tools to respond to the changing climatic conditions.  We know that the globe is connected ecologically, and that the global climatic system affects ecosystems down to the local level.  The rate of these changes is now unprecedented.  However, by applying ecological principles and concepts on the ground, through direct local actions such as invasive plant removal, re-establishment of local native species, and protection and enhancement of rare plants, animals and ecosystems, the effects of climate change can be reduced.  Citizens can learn about their local ecosystems, and adapt and restore as a learning opportunity.  Local ecological actions can help to overcome the sense of helplessness that occurs in the face of the scale of global climatic changes.

Essential Points

• Widespread climate change is already underway;
• Ecosystem change is now underway;
• Past climate changes will foster widespread ecosystem changes in the future;
• Natural ecosystem change takes place at the species level from within, through immigration, and through local species loss;
• Ecosystem change lags behind climate change and may not be gradual (could be sudden);
• Amplitude and rate of ecosystem change have few recent precedents;
• Ecosystem instability is likely to occur for many decades/centuries;
• General features of future ecosystems can be projected but composition and structure and trajectory of change is difficult to foresee;
•  Restoration from preservation to active manipulation provides adaptive strategies but cannot stop widespread ecosystem change;
• Support assisted migration of species now, without delaying because of moral uncertainty.