By now, almost no one denies that humans have created a major climate disruption. Millions of years ago, during a period paleontologists called the Carboniferous, swampy forests all over the globe trapped atmospheric carbon and stored it in the form of carbohydrates – tissues that comprised the trunks and leaves or needles of the trees. When those trees died, that carbon fell to the earth and over millions of years and intense heat and pressure, it became coal. Elsewhere, the zooplankton and algae deposited on lake and sea bottoms mixed with mud and, over geologic time, changed chemically into the fossil fuels we now burn. All that fuel – coal to heat homes and run electric plants, gasoline to run our cars, factories, planes, and so on – is releasing carbon back into the air in the form of carbon dioxide. This is carbon that’s been trapped – sequestered – for millions of years, but in just the last 200 years, we have released enormous quantities of it into the atmosphere. There it acts like the panes of glass in your car when it’s parked in the sun. Know how you come back to the car after it’s been parked for a while, and the temperature in the car is way higher than the temperature outside? The air inside has heated up because it had no way to release the sun’s energy. Something similar has happened in the atmosphere, which is why scientists call this ‘the greenhouse effect.’
Some of you probably have mini-greenhouses in which you start seeds and seedlings. These can be glass or plastic – they can even be plastic wrap that you put on top of your seedtrays. It’s the same principle: you trap the heat and moisture. It’s good for seeds, but what does it do to plants? To gardens?

The most immediate evidence of global climate disruption is the increased incidence of dramatic weather events – floods, hurricanes, droughts, tornadoes, tsunamis – that will be occurring with increasing frequency in the next century. The climate we’re used to in our areas may be more variable than we’ve come to expect. These are aggravated by the extent of development that makes is impossible for nature to absorb dramatic events, as we saw in New Orleans, where the wetlands in the delta area had historically absorbed additional stormwater. The development of those wetlands meant there was not enough uninhabited natural area to allow the earth, like a sponge, to soak up the extra rain.

But plant life is clearly affected too. According to the Brooklyn Botanic Garden, both spring wildflowers and spring-flowering woody plants have been blooming earlier and earlier because the soil is warming earlier. Cornell University found that 40% of the species in a study of spring wildflowers were blooming an average of 19.8 days earlier over 50 years. A Wisconsin study on the property of Aldo Leopold, the naturalist and philosopher, found that from 1936 to 1999, spring began an average of .12 days earlier per year. All these are called phonologic changes – phenology is the study of the timing of biological events.

Isn’t this good news? Don’t we want longer growing seasons, more time to enjoy our gardens? Maybe in the short run it’ll mean that I can actually have a flowering dogwood in my zone 5 garden, but the news isn’t so good on other scores. For one thing, diseases that have been killed by cold in the past will now be able to spread further, and so will invasive plants. For another, earlier flowering and fruiting could disrupt the migratory patterns of birds. Plants may need pollinating before the insects arrive; birds may not migrate when plants are fruiting.

Moreover, plants in the wild – the plants of our great forests, prairies, deserts, and mountains – can’t migrate the way buffalo, geese, and people can. Plants do, in fact, migrate, and the natural cycles of heating and cooling that have overtaken the planet in the past have seen large-scale migrations of plants, but that takes centuries, which has been the norm of change in the past. Think about it: how can a pine tree move north when the weather has become too hot for it? It can’t, but maybe the seeds of the northernmost pines will get moved even further north by animals. There, they’ll germinate, and when the offspring are mature enough to produce seed – which can take many years – their seed will be carried even further north. And so on. But that takes generations. In the meantime, diseases and droughts may well wipe out our forests.
In our gardens, we are likely to be able gradually to grow plants that have been outside our zone. Take a look at this web link: view link to get an idea of how planting zones have changed just in the last two decades, according to the Arbor Day Foundation. Of course this also means that we may now find that plants adapted to more northern conditions don’t fare so well for us. Gain a few, lose a few.

But we also need to think about climate in terms of precipitation and water use. (Warning: rant ahead) As far as I’m concerned, people in dry climates should not have lawns. Watering grass every day when that water is being taken out of our dwindling aquifers where it will not be replenished is not worth it! There are lots of gorgeous alternatives to the bluegrass lawn. We need a new aesthetic. (Rant over. For now.)
If you live in a dry climate, plant xeric species. They’ll be happy, you’ll be happy, your garden will be gorgeous, and you won’t be watering all the time. If you live in a wetlands, plant wetland species. They’ll be happy, you’ll be happy, your garden will be gorgeous and you won’t be worrying about drainage.

If you don’t know the drainage capacity of your soil, there’s a test you can do. First, you need to corral a person who likes to dig: maybe a child or robust grandchild. Dig a hole 18-24” deep in your garden (width doesn’t matter). Fill it with water and let it drain overnight. In the morning, fill it again. Put a yardstick – or any strong stick – into the hole and check it every hour or so. If it’s draining less than half an inch/hour, you have soil that’s not well drained, and you need to plant accordingly. If it drains a half inch to an inch/hour, your soil is moderately well drained, and you can plant wet site as well as other species. If it drains at more than an inch an hour, it’s well drained. If it drains really fast, you should probably add compost to the soil to improve the texture and the nutrient value.

Here’s another way you may be able to get involved. Part of the difficulty of understanding global climate disruption is that it’s so difficult to collect enough data; here’s where the citizen scientists come in. In Canada there’s a project called Plant Watch; in it, citizens monitor the first bloom times of certain species and report them to a central data gathering site. If you do a web search with the term ‘plant watch’ you’ll find this site right away, but you may also find one for your area. Project Budburst (www.windows.ucar.edu/citizen_science/budburst) tracks phenologic changes in the U. S. In my area we also have butterfly monitors, river monitors, and prairie and woodland monitors. People are taught how and when to collect data, and their observations help create databases of unusual size. School kids and teachers do these, but so do ordinary folks like you and me. It’s a very satisfying way to feel like you’re part of the solution – or at least the information gathering.

That’s it for today. Let me know what you think about how global climate disruption is affecting your area, and what we can do about it. And do visit my website at view link