The planet is experiencing a new wave of die-offs driven by factors such as habitat loss, the introduction of exotic invaders and rapid changes to our climate. Some people have called the phenomenon the sixth mass extinction, on par with the catastrophic demise of the large dinosaurs 65 million years ago
The problem with climate change could be summed up in a few words: it disrupts nature’s balance too fast for ecosystems to adapt and resist the change. Ecosystems are often based on a very delicate balance, on cycles that have evolved over millenniums. A fire destroying thousands and thousands of acres of forest land may seem like a huge catastrophe, but in fact, it’s part of a cycle that makes room for new growth. Most seeds on the ground resist the fire and a new forest can grow in a matter of years.
When climate change makes temperatures go up by just a few degrees, many of us don’t even notice. What’s just a few degrees? For many years, scientists and ecologists from around the globe have been warning us that just a slight variation in temperatures has the potential for major disruption. And we are now starting to witness what they have been forecasting for years. Just a small rise in temperatures actually means death for billions and billions of trees over millions of acres of forest land. It’s happening now in the US Rockies and over most of Canada.
Climate change has a huge, multi-faceted impact on everything that’s important to everything that grows.
Climate change affects:
- Ground temperatures. The problem with rising ground temperatures is not so much the ability of plants to adapt to warmer climates, although this can be an issue with some plants, but rather the fact that insects and diseases that are sensitive to cold can start to thrive in locations where they could never before survive. The mountain pine beetle (also called black hills beetle) is a good example. The harsh winters in northern North America used to kill their eggs and thus prevented their spread. With climate change, the eggs can now make it through the cold season and hatch in the spring. The rise in temperatures is directly linked to the spread of mountain pine beetles on the Rocky Mountains in the United States and Canada, as well as in many other parts of Canada. Now billions of trees that have no defense whatsoever against this new bug are under attack.The mountain pine beetle is just an example. Insects and diseases don’t need passports to cross state and national boundaries. So if you start seeing bugs you’ve never seen before, or if your plants start to wither for no apparent reason, beware. A newly naturalized insect or disease may be sucking it’s life away.
- Cycle of water. Climate change also has a direct impact on water evaporation, be it on the ground or on bodies or water, as well as on what happens to that water afterwards. So places that very rarely encountered drought conditions in the past are becoming more and more at risk. And locations that used to have regular, moderate rainfalls are starting to get frequent downpours. Let’s take Australia, for instance. Most of eastern and south-western Australia has experienced substantial declines in rainfall since the 1950’s, while north-west Australia has become wetter over the same period.Almost every week we hear on the news about downpours that flood whole regions or cause mud slides. Many governments have created groups that study the long term effects of climate change and that advise decision makers on how to cope with new and future climatic events. The US Global Change Science Program, the Pacific Climate Impacts Consortium and the Consortium on Regional Climatology and Adaptation to Climate Change are just a few examples.Unfortunately, plants can’t move or adapt the way humans can when the weather conditions don’t suit them anymore. And gardeners can’t change their mature plants and trees to keep with the changing conditions. So less water and more droughts may be fatal to some plant species, just as more water and downpours may fatal to others. Furthermore, changes in humidity levels also have a direct impact on insect populations and diseases. So plants that are made more fragile by changing water conditions may be killed by disease or by changes in the balance between good and bad insect populations.
What to do to cope with climate change
Coping with climate change is a tall order. In some cases, there is just nothing that can be done. Unless drastic measure are taken right now, which we don’t see happening, coastal areas in many countries are just doomed. The same is unfortunately true for entire forests and ecosystems. These will certainly be replaced by other ecosystems, but the whole process will just as certainly wreak havoc with wildlife as well as human populations, not to mention the incalculable financial impacts. And what about the impact on biodiversity? Only the future will tell.
So how can gardeners and landscapers find ways to cope with climate change? Since different regions are affected differently, the first thing is to document yourself on what is happening in your part of the globe.
- Physical observations are very important. How do you see your local weather evolving? What do you notice in your garden? Do you see new bugs? Are some plants changing?
- Information from your local weather authorities as well as from organizations that monitor and study the effects of climate change are also essential in planning for the future.
- Finally, you can get invaluable information from botanical gardens in your region. They are at the front line of this battle. Botanical garden management teams are responsible for the preservation of the plants under their care as well as for adapting to present and future conditions. Some botanical gardens organize public presentations on climate change. Some city halls even hold such events. So ask around. And if you do have the chance to go to such a presentation, don’t hesitate to ask concrete questions on what you did notice in your own garden.
Putting together all this information will definitely help you see where things are likely to be heading. And this will help you plan your strategy for coping with climate change in your area.
Rainfall and humidity are on the rise
If climate change brings more rain to your location, there are a few things you can do to try to deal with these changing conditions.
- If your home is not equipped with a French drain (also known as a weeping tile), then it may be a good idea to consider having one installed. If may cost you a fair amount, but it will protect your house’s foundations as well as drain the excess water that could rot your plant’s roots.
- Bring in plants that thrive in wet locations (see our pages on Wet sun plants and Wet shade plants). With enough wet plants draining moisture away, you may even be able to save those plants that don’t enjoy damp soil so much.
- For more information on this topic, be sure to have a look at our Lawn drainage page.
Rainfall and humidity are dropping
If climate change brings less rain to your location, there are also a few things you can do.
- You may need to start thinking about replacing plants that thrive in wetter locations with plants that thrive in dryer locations (we can suggest a site called Drought Smart Plants).
- If your lawn is suffering from the dry weather, you may start to overseed it with turf grasses that do well in dryer locations. Other plants, such as creeping thyme, may be considered, as it can really thrive in well drained, sunny locations. For more information, have a look at our Grass replacement page.
- Water your yard wisely. The best time to water your yard is before dawn, as less water is lost to evaporation before the sun starts to shine its rays, and as more water is absorbed by your plants when the sun does come up. You can always connect your garden hose and sprinkler or drip irrigation tubing to a watering timer or let your sprinkler system do it all for you while you sleep.
New bugs and diseases are starting to appear
Since climate change means higher temperatures and winters that are less harsh, it is most likely that you may start to see bugs and diseases that you never saw before.
- The first thing is to identify the new bug or disease. A picture of the bug itself or the damage it causes will definitely help in the identification. If the bug is new in your location, information on it may be hard to find, so once again, getting help from your botanical garden may be a good idea. The more you know on this new bug, the better you can fight it.
- Bear in mind that green pesticides may fight the bug directly while green fertilizers may help your plants fight it. Bugs that are attacked on both fronts may very well decide to look elsewhere for a place to spread.
- The Beetles are Coming, The Nature of Things, CBC
- Intergovernmental Panel on Climate Change: Frequently Asked Questions
- LA Times: Climate change will increase extreme precipitation levels
- National Union of Public and General Employees: Climate change is raising rainfall levels across Canada
- The Guardian: How will climate change affect rainfall?
- The Week UK: Extreme rainfall on the rise, is climate change to blame?
- Department of Climate Change and Energy Efficiency, Australia: Climate Change in Australia
- European Journal of Plant Pathology: Impacts of climate change on plant diseases
- Science Daily: Climate change complicates plant diseases of the future
- FAO: Climate change impacts on forest health
- Canadian Journal of Plant Pathology: Climate change and plant diseases in Ontario
- Climate change: impacts and adaptation in England’s woodlands
- Kansas State University: Climate Change Effects on Plant Disease
- Joint Study, Chile: Predicting insect pest status under climate change scenarios