Blog
What Planting Tomatoes Teaches Us About Climate Change
Aug
In my hometown there is a gardening tradition that has been passed down through the generations: never plant tomatoes before Show Day, which in Tasmania falls on the fourth Saturday in October. If you are unwise enough to plant them earlier, your tomato plants will suffer during the frigid nights and will not grow.
But does this kind of seasonal wisdom still work as the climate changes? We often talk about large-scale climate change—how much the average global surface temperature will rise.
Nations are trying to keep the temperature rise to well below 2°C. That doesn’t sound like much when you take that as an average – after all, temperatures change much more as day gives way to night. But remember – before the industrial revolution, the average surface temperature of the Earth was 12.1°C. It’s almost a degree warmer now – and could be as much as 3°C warmer by the end of the century if high emissions continue.
Climate change may seem abstract to many of us. However, the natural world is very sensitive to changes in temperature. Everywhere we look, we can see that the seasons are changing. Gardening knowledge is no longer relevant. Flowering may occur earlier. Many species must migrate or become extinct. Here’s what you may notice.
Snapshot
Spring comes earlier
Warmer temperatures mean spring is coming earlier, with Australia now seeing five shorter days than it did between 1950 and 1969, according to the Australia Institute testsTrees and plants sprout novel leaves days earlier.
For some Australian plants, earlier spring means earlier flowering and fruiting – an average of 9.7 days earlier per decade.
The celebrated spring cherry blossoms in Japan are bloom earlier than in centuries. Last year’s cherry blossom peak was the earliest bloom on record in records dating back to 812.
Not only are flowers blooming earlier, but birds are too migration earlierand it can also delay them autumn migrations.
Summer is getting warmer and longer
A warmer planet means warmer and longer summers.
It may not seem that way this year with so much rain, but the overall trend is clear. This means the risk of bushfires is rising year after yearwith more days of high and catastrophic fire danger. An additional 48,000 hectares of forest have burned across Australia each year for the past three decades.
Longer fire seasons make it more tough to plan fossil fuel burn and reduce the time firefighters have to rest and recover between fire seasons.
Warmer temperatures are already a challenge for salmon farmers in Tasmania. Atlantic salmon grow best in cold water and climate change has already raised ocean temperatures. In summer, the waters around Tasmania are close to fish limitWarmer summers will pose a sedate challenge for salmon farmers in the future.
Warmer water also caused almost all of Tasmania’s giant algae to die off, allowing warm-water fish to migrate south.
For millennia, the North Pole has been covered in sea ice. That is changing, too. The Arctic sea ice is melting earlier in summer and freezing later in winterAs warming intensifies, the central Arctic will likely transition from a eternal ice sheet to an ice-free state. through the summer by the year 2100.
Read more: Australia’s Black Summer of Fires Wasn’t Normal – and We Can Prove It
Snapshot
Autumn is delayed
In early autumn, the leaves of the nothofagus, the only one in Australia temperate deciduous treethey change color and fall to the ground, as does many trees in the northern hemisphere.
Here too we can see climate change. Around the world, warmer temperatures and rising levels of carbon dioxide in the atmosphere are Delay in arrival With autumn colors by a maximum of one month.
Winter is disappearing
Alpine species such as the mountain pygmy possum have life cycles built around winter snow, while many cities around the world rely on snowmelt for their water supply. Snowfall in Australia it was decreasing in recent decades.
In a warmer world there is less snow and ice. This is creating serious challenges for cities like Santiago in Chile, as well as semi-desert areas in the United States that have it was about melting snow.
Species are on the move
What else might you notice? Different animals, birds, fish, and plants. Not only are the seasons changing, but many species can now be found in areas where they could not survive before.
Tropical corals have already been found happily growing near SydneyCoral reef fish are also moving south, to areas far removed from their natural habitat. historical scope.
Some of the surprising novel discoveries can be seen in a citizen science project Red mapsuch as tropical observations yellow-bellied sea snake in Tasmanian waters.
Read more: Thousands of photos taken by ordinary Australians reveal secrets of our marine life as oceans sultry
For First Australians, climate change is bringing other shocks. The seasonal link between, say, the flowering of acacia trees and the emergence of fish species is breaking down.
Changes everywhere
Climate change really does mean change—on both immense and petite scales. From extreme weather to changing ecosystems to when you can plant tomatoes.
For gardeners, this means that conventional wisdom is no longer valid. In Tasmania, it is now safe and sound to plant tomatoes 18 days earlier than in the 1900s. This is because October minimum temperatures are now about 1°C warmer than in 1910.
Climate change is changing the seasons and transforming our world in both obvious and subtle ways.
So while planting tomatoes may seem like a petty example, it’s another sign that the climate around us is changing. This isn’t a problem for the distant future. It’s our problem, right now.
