A recent article from The Independent claims that warming average temperatures in the UK are causing more plants to bloom during winter, which point towards “climate breakdown.” This is hyperbolic, there is no reason to fret over daisies blooming in winter. The Independent ignores the urban heat island effect on local temperatures, and is also ignoring the substantial benefits of a greening world, and the contribution of carbon dioxide itself to that greening.
The post, “Daisies and dandelions among plants blooming in winter due to climate change,” describes how a botanical study conducted by the Met Office found that “for every 1°C rise in temperature at a given location, an average of 2.5 additional plant species are observed in bloom,” during the wintertime. The overall count was large, with the study recording 310 native species in January, versus the 10 they would normally find. The Independent says the extra wintertime plants found in gardens across the UK is evidence of “climate breakdown.”
A “vegetation expert” at the Met Office told The Independent that the study’s results “underscore how rising temperatures and increasing climate extreme events are shifting the natural cycles of our plants and wildlife[.]”
There is one glaring issue here, and that is that it should be expected for plants in people’s urban and suburban gardens to struggle less in winter compared to those in the exposed countryside. Over time, the urban heat island effect causes developed areas to warm more, due to the heat-trapping properties of concrete and asphalt, metal surfaces and mechanical equipment. This is not a minor effect; temperatures in developed areas, especially at night when heat is released by hard surfaces, can be 10 degrees warmer or even more than that in certain environments. That could very well be the difference between freezing and thawing. The effect increases (to a point) as urbanization increases.
As outlined in the scientific study, “Urban heat island impacts on plant phenology: intra-urban variability and response to land cover,” plants sense temperature as a primary environmental signal to know when spring has arrived. The UHI effect results in consistently elevated temperatures in urban areas compared to surrounding rural regions, especially in the spring and fall. UHI boosted temperatures have three major impacts on plants: accelerated growth, heat accumulation leading to earlier flowering, and some plants which require a certain amount of chill hours during winter will be impacted.
Photosynthesis and cellular division speed up in warmer ambient temperature so long as those temperatures are still within the species’ optimal range. In other words, warmer temperatures speed up plant growth, it should be no surprise that this would be true particularly for winter temperatures.
UHI also traps and accumulates heat faster in the spring in affected areas faster than they would otherwise, which means plants experience the springtime bloom temperature signal earlier.
A potential negative is the fact that some plants require a specific period of cold temperatures (known as vernalization) during winter to bloom in spring. Warmer winters associated with the UHI effect can sometimes disrupt this process. However, strong spring warmth often overrides this, still leading to an overall earlier bloom time for most species.
One good example of this is the early blooming of Washington DC’s famous cherry trees, covered by Climate Realism in “Sorry, ABC News, Early Cherry Blossom Bloom Is Due to Urban Heat Island, Not Climate Change.” The urban heat island effect has a substantial influence over nighttime lows. It should be expected that a warmer year will also result in warmer UHI, which would protect flowering plants from freezing, or give them a chance to blossom in a temporary wintertime “Indian summer.”
It is certainly not a catastrophe, and the modest warming of the past decades is also part of a much longer warming trend that predates industrialization, especially for Europe. Temperatures in Europe have increased 2°C since the warming trend began around the mid-1800s as the planet recovered from lows set during the Little Ice Age. During that cold period, famine and death dominated.
A colder planet is a less friendly planet to plants and animals. One of the most substantial benefits to the world brought by the modest warming over time has been increased agricultural production and the increase in vegetation, or greening of the planet. This is also boosted by the amount of carbon dioxide in the atmosphere, which helps plants resist droughts and grow larger. While The Independent worries about out of season daisies in their gardens, 2023 and 2024 were both world record global crop yield years, which means that more crops than ever were produced on less land than needed in past years. More people can be fed with less land being used for agriculture.
This year might have been warm for the UK, and it is unusual to have so many flower plants in deep winter, but it is hardly evidence of anything breaking down. Change is a natural part of the planet’s history, and a world that is friendlier to life is not alarming.
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