by Jane Mower
BBC News website, London
When Philip Williams spotted an avocado growing on a tree in west London he was ridiculed, first by a taxi driver and then by his wife.
Mr Williams was in a taxi when he spotted the avocado
"The cabbie said 'Don't be so ridiculous' - and when I went home to my wife she said I was talking nonsense - so I phoned Kew Gardens," he said.
It was then experts said that although they could not confirm this was a first in England, it was unusual.
Indeed Tony Kirkham, Head of Arboretum at Kew Gardens in west London, said this could become a more frequent sight as our climate becomes warmer.
Scientific evidence currently predicts a 2-6C rise in temperature this century and nine of the hottest years on record have occurred in the last decade.
Mr Kirkham said: "With the weather pattern we have had over the last three years with hot summers and into the autumn.... we will start to see more unusual things.
"We will definitely see more fruit trees planted, more cross pollination and there will be quite a change in the landscape."
This is reflected in the planting at Kew this year where Olive, Stone Pine and Cork Oak trees, all of which originate from the Mediterranean, have been selected.
Over the last 10 years olive trees have established themselves as a regular feature outside restaurants and cafes.
And Mr Kirkham believes it will not be long before they begin bearing fruit in this country.
"They need a lot of sun and if they can get through the first winter they should survive," he says.
"If we have a hot summer that promotes flowers the following year I reckon they could bear fruit eventually.
"10 years ago you never saw any olive trees in this country, except at Chelsea Flower Show where it would have been the star of the show.
"Now you can go into any garden centre and they are selling them as the climate is more akin to that of hot countries."
This case highlights that while climate change will result in us losing some species of plant and wildlife, others will arrive and flourish in the warmer climate.
Avocado pear trees originate from Central America and Mexico
With each passing year the onset of spring comes earlier, bringing with it an increase in certain species of birds, butterflies and plants.
According to the UK Phenology Network, for every 1C rise in temperature the timing of spring is roughly six days earlier.
Birds like the Little Egret are now seen frequently in the south, since their arrival around 20 years ago.
The Cetti's Warbler is also now seen in southern wetlands and the Nuthatch, Serin, Lesser Blackbacked Gull and Dartford Warbler have started moving northwards too.
But there are the more obvious signs found on our doorstep of which we are becoming increasingly aware.
The BBC's Springwatch project encourages us to record the first signs of spring, such as frog spawn, bumblebees and swallows, making us acutely aware of how the seasons are changing.
Possible new species
Spanish Carpet (moth)
Although some species are clearly benefiting from increased temperatures experts are predicting these "differential responses may disrupt the complex linkages in nature".
It is also not known how many garden plants or native species may become pests as the British climate becomes more suitable for them.
But the one thing that is clear is the need to act now in order to help the natural world survive and adapt to future change.