[News] from [guardian.co.uk]
[Environment > Climate change]
Gardens of 2050: January cherry blossom and winter buttercup blooms
Spring will arrive a month earlier in 40 years' time thanks to the warming oceans around British Isles, new study predicts
Severin Carrell, Scotland correspondent
The Guardian, Thursday 10 September 2009 A
It is a discovery which should delight Britain's gardeners: by 2050, spring will start before Valentine's day. Cherry and pear trees will blossom in late January, while flower beds will be crowded with blooming buttercups, iris and geraniums long before winter has officially ended.
A new study on the impact of our warming climate has found that across most low-lying, coastal areas of the globe, spring will begin for many plants at least a month earlier than it does now and will end several weeks later in 40 years time.
The predictions are based on a detailed study of plant records from the Royal Botanic Garden in Edinburgh (RGBE) from 1850 and weather records for Edinburgh dating back to 1775, by two scientists, Malcolm Clark of Monash university in Australia and Roy Thompson, at the University of Edinburgh.
They have confirmed that the "botanical calendar" has changed for scores of plants in the RBGE collection, which for more than 150 years has gathered plants from across the globe, are now flowering earlier as average air temperatures slowly but steadily rise. The most affected are plants such as ornamental cherry, peach and pear trees, anemones, saxifrage, irises and perennials such as three-leaved bittercress.
But Clark and Thompson warn that an ever-earlier spring is likely to create significant problems for the plants affected, for farmers and for many of the bird and insect species which rely on them.
As flowering plants move out of step, or "desynchronise", with normal seasons, serious problems may emerge with the pollination of the plants involved. They may flower before the birds and insects that feed on them, or the mammals that carry their pollen, are at large. Most animal behaviour is guided by the length of the day rather than temperature.
They believe the worst-affected places will be low-lying coastal regions of the world and places with maritime climates like the British Isles and western Europe, the Atlantic coast of north America as far south as Florida, New Zealand, Chile and north Africa.
The true start of spring is already a controversial subject. Traditionally, spring starts with the vernal equinox on about 20 or 21 March and ends with the summer solstice on 21 June, but for statistical and record-keeping purposes, the Met Office officially records spring as starting on 1 March and ending on 31 May.
But with continued global warming , these dates are likely to become even less meaningful.
In maritime areas, for every 1C of warming, flowers will bloom as if spring had begun 16 days earlier and ended 11 days later.
Using widely accepted predictions that the world's climate will warm by at least 2C by 2050, leading to warmer winters, this would mean that spring in the British Isles will no longer start on 1 March, but in late January, and end in late June.
In continental regions, further from the warming effects of the oceans, the impact will be lessened but still significant, with the flowering starting seven days sooner and ending 11 days later for every degree of warming.
"Already there is a great deal of observational evidence of regional changes in climate associated with global warming," said Clark. "We have not only seen an earlier break up of ice on rivers and melting glaciers, but also the early emergence of insects, egg laying by birds and the flowering of plants. This new model allows us to refine predictions of the future impact of warming on plant and animal life across much of the world.
"Although the study is based on plant life in Scotland, our models apply across regions spanning hundreds of thousands of square kilometres," said Clark.
But the full impact this will have on the environment is still very difficult to predict. Some plants are more sensitive to temperature changes than others; in some regions, there will be plants and trees that are not heavily affected growing alongside other plants flowering weeks earlier than normal.
Thompson also fears that the pace of climate warming is faster than the ability of plants – particularly long-lived trees - to adapt and evolve, leaving some at risk of dying out in many areas. "We're predicting very fast rates of change. In the past, plants have kept pace with the climate and after the last ice age thawed had lots of time to migrate. In the future, that's most unlikely to happen," he said. "It seems to me inevitable that they're going to be many extinctions."
He is also highly pessimistic about how much warming the world faces, which could see temperatures rising by as much as 5C by 2100 . By then, some plants will be flowering shortly after Christmas.
"I'm a geophysicist, and I've trained my students to find oil. I think they're going to find every last drop of it, and that the Chinese and Indians will extract all the world's oil and that the world's population will increase. If you believe that, the world will continue warming."
Other climate changes
Fish
Cod and haddock are just two of the North Sea fishes that have had to move scores of miles north in search of cooler waters. Sea temperatures have risen by 1C in the past 25 years and more exotic southern species have entered North Sea waters. Scientists at the University of East Anglia found that 21 species had shifted their distributions in line with the rise in sea temperature, and 18 species had moved much further north.
Trees
As climate change affects rainfall around the world, many species of trees are not able to adapt quickly enough. The dimb tree in Senegal is struggling to survive the drier and hotter conditions there and, closer to home, scientists have warned that oak trees will be severely affected if nothing is done to stem temperature rises..
Birds
The British Trust for Ornithology found that, in the period 1971-1995, 51 species of birds tended to nest and lay eggs earlier (around a week or more on average) as background temperatures increased. The species included the wren, nuthatch, starling and also waterbirds such as the oystercatcher, curlew and redshank.
Mosquitoes
The average temperature in Europe has increased by almost 1C in the past century and could rise by a further few degrees by the end of this century. The World Health Organisation has warned that malaria-carrying mosquitoes will find their way out of the tropics as the world warms and could even end up in southern England at some point.
Wine
Global warming is threatening to play havoc with the carefully managed crops in the vineyards of California and France. The warmer temperatures can mean that the grapes make their sugar too early, before the fruit is ready to be picked - this can affects the final taste and alcohol content of the wine.
Alok Jha
[Environment > Climate change]
Gardens of 2050: January cherry blossom and winter buttercup blooms
Spring will arrive a month earlier in 40 years' time thanks to the warming oceans around British Isles, new study predicts
Severin Carrell, Scotland correspondent
The Guardian, Thursday 10 September 2009 A
It is a discovery which should delight Britain's gardeners: by 2050, spring will start before Valentine's day. Cherry and pear trees will blossom in late January, while flower beds will be crowded with blooming buttercups, iris and geraniums long before winter has officially ended.
A new study on the impact of our warming climate has found that across most low-lying, coastal areas of the globe, spring will begin for many plants at least a month earlier than it does now and will end several weeks later in 40 years time.
The predictions are based on a detailed study of plant records from the Royal Botanic Garden in Edinburgh (RGBE) from 1850 and weather records for Edinburgh dating back to 1775, by two scientists, Malcolm Clark of Monash university in Australia and Roy Thompson, at the University of Edinburgh.
They have confirmed that the "botanical calendar" has changed for scores of plants in the RBGE collection, which for more than 150 years has gathered plants from across the globe, are now flowering earlier as average air temperatures slowly but steadily rise. The most affected are plants such as ornamental cherry, peach and pear trees, anemones, saxifrage, irises and perennials such as three-leaved bittercress.
But Clark and Thompson warn that an ever-earlier spring is likely to create significant problems for the plants affected, for farmers and for many of the bird and insect species which rely on them.
As flowering plants move out of step, or "desynchronise", with normal seasons, serious problems may emerge with the pollination of the plants involved. They may flower before the birds and insects that feed on them, or the mammals that carry their pollen, are at large. Most animal behaviour is guided by the length of the day rather than temperature.
They believe the worst-affected places will be low-lying coastal regions of the world and places with maritime climates like the British Isles and western Europe, the Atlantic coast of north America as far south as Florida, New Zealand, Chile and north Africa.
The true start of spring is already a controversial subject. Traditionally, spring starts with the vernal equinox on about 20 or 21 March and ends with the summer solstice on 21 June, but for statistical and record-keeping purposes, the Met Office officially records spring as starting on 1 March and ending on 31 May.
But with continued global warming , these dates are likely to become even less meaningful.
In maritime areas, for every 1C of warming, flowers will bloom as if spring had begun 16 days earlier and ended 11 days later.
Using widely accepted predictions that the world's climate will warm by at least 2C by 2050, leading to warmer winters, this would mean that spring in the British Isles will no longer start on 1 March, but in late January, and end in late June.
In continental regions, further from the warming effects of the oceans, the impact will be lessened but still significant, with the flowering starting seven days sooner and ending 11 days later for every degree of warming.
"Already there is a great deal of observational evidence of regional changes in climate associated with global warming," said Clark. "We have not only seen an earlier break up of ice on rivers and melting glaciers, but also the early emergence of insects, egg laying by birds and the flowering of plants. This new model allows us to refine predictions of the future impact of warming on plant and animal life across much of the world.
"Although the study is based on plant life in Scotland, our models apply across regions spanning hundreds of thousands of square kilometres," said Clark.
But the full impact this will have on the environment is still very difficult to predict. Some plants are more sensitive to temperature changes than others; in some regions, there will be plants and trees that are not heavily affected growing alongside other plants flowering weeks earlier than normal.
Thompson also fears that the pace of climate warming is faster than the ability of plants – particularly long-lived trees - to adapt and evolve, leaving some at risk of dying out in many areas. "We're predicting very fast rates of change. In the past, plants have kept pace with the climate and after the last ice age thawed had lots of time to migrate. In the future, that's most unlikely to happen," he said. "It seems to me inevitable that they're going to be many extinctions."
He is also highly pessimistic about how much warming the world faces, which could see temperatures rising by as much as 5C by 2100 . By then, some plants will be flowering shortly after Christmas.
"I'm a geophysicist, and I've trained my students to find oil. I think they're going to find every last drop of it, and that the Chinese and Indians will extract all the world's oil and that the world's population will increase. If you believe that, the world will continue warming."
Other climate changes
Fish
Cod and haddock are just two of the North Sea fishes that have had to move scores of miles north in search of cooler waters. Sea temperatures have risen by 1C in the past 25 years and more exotic southern species have entered North Sea waters. Scientists at the University of East Anglia found that 21 species had shifted their distributions in line with the rise in sea temperature, and 18 species had moved much further north.
Trees
As climate change affects rainfall around the world, many species of trees are not able to adapt quickly enough. The dimb tree in Senegal is struggling to survive the drier and hotter conditions there and, closer to home, scientists have warned that oak trees will be severely affected if nothing is done to stem temperature rises..
Birds
The British Trust for Ornithology found that, in the period 1971-1995, 51 species of birds tended to nest and lay eggs earlier (around a week or more on average) as background temperatures increased. The species included the wren, nuthatch, starling and also waterbirds such as the oystercatcher, curlew and redshank.
Mosquitoes
The average temperature in Europe has increased by almost 1C in the past century and could rise by a further few degrees by the end of this century. The World Health Organisation has warned that malaria-carrying mosquitoes will find their way out of the tropics as the world warms and could even end up in southern England at some point.
Wine
Global warming is threatening to play havoc with the carefully managed crops in the vineyards of California and France. The warmer temperatures can mean that the grapes make their sugar too early, before the fruit is ready to be picked - this can affects the final taste and alcohol content of the wine.
Alok Jha
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