Rising temperatures put the heat on for Capital's wildlife

Published on Wednesday 20 February 2008 08:15

Global warming may be having a minimal effect on our lives so far but average temperatures continue to rise in Edinburgh. Joanna Vallely looks at how the city's fauna is adapting to the changes.

MANY of us secretly welcome the news of global warming in the gleeful hope of milder winters and warm summers more normally associated with Mediterranean climes.

Last spring was the second warmest ever in Scotland and Edinburgh's average monthly temperature has risen steadily since the mid-1970s.

It's official – the Capital is heating up along with the rest of the planet, where the average global mean temperature of 14 degrees is expected to rise by a degree to a degree-and-a-half by 2050.

In the 1960s and 70s, the mean February temperature in Edinburgh barely wavered from around three degrees centigrade. But in the last two decades, it has been climbing steadily, and for the past five years has steadied at around five degrees, peaking at eight in 1998.

In the last 60 years, only on three occasions has the mean temperature for the month been below freezing.

But while warmer weather may offer opportunities to grow a greater range of crops and the potential of a thriving tourist industry outside of the Scottish ski season, we can't be complacent about the long-term effects of these changes.

Despite the unseasonal temperatures, last month was the wettest in Edinburgh for more than 100 years, with nearly three times the average amount of rainfall. It's this unpredictability that is threatening creatures who have shaped their lifestyles to cope with the four seasons we have traditionally come to expect. For them, changing temperatures can be a matter of life and death.

Animal welfare officers have said they fear for dozens of fox cubs and fledgling birds that will be born too soon this year because of the early onset of spring. Early births in the mild weather mean that, if we suffer a sudden cold snap, the newborns may still be too little to survive.

On a grander scale, Sasha and Yuri, Edinburgh Zoo's pair of Siberian tigers, are being moved north to the Highland Wildlife Park, where it's said they will enjoy the chillier Cairngorms climes.

Met Office forecasters have put the steadily-rising temperatures down to global warming caused by the greenhouse effect – although no definitive proof has yet been presented as to the causes.

The much-feared global phenomenon is predicted to make some islands completely disappear under rising sea levels, while African countries will suffer further drought.

Meteorologist Barry Gromett says the changes in the UK will be less dramatic, though the potential is there for serious impacts on health, particularly due to increased frequency of heatwaves and the temperature of the hottest days.

If a particularly hot day in London may currently reach 35 degrees, by 2050 city dwellers may have to cope with 40 degrees of blistering heat.

HERE in Scotland, the impact of global warming will bring milder, wetter winters, drier summers – and the advance of spring. Barry says: "Overall, the trend shows an increase in temperature, which is down to climate change and caused by greenhouse gas emissions.

"No matter where you are in the UK, there's a distinct trend to see signs of spring – spring bulbs, leaves on trees – earlier.

"Over the last 100 years we have seen spring advance by four weeks. You used to have spring occurring in mid or late March, but we now see the same signs occurring in mid-to-late February."

Which is why the sight of daffodils and other spring flowering plants can already be seen throughout the city. Colin Seddon, of the Scottish SPCA, says the early spring is spelling havoc for some animals.

He explains: "Most animal breeding in the wild is timed to coincide with abundant food supplies. When you have a mild spell and then cold, it confuses the plants and insects and the animals that have had young. If a heavy frost comes, suddenly food is gone and the young won't survive.

"The top of the food chain is most at risk – predators like blue tits and songbirds. Because they are so small they are not built to cope with the temporary loss of food supply, such as bugs.

"Frogs and toads will produce spawn early this year because we have had a mild spell, but then the frost will get them. Hedgehogs will wake up from hibernation and find no food and might then go back to sleep again."

However, the consequences of global warming may not be so negative for all Scotland's wildlife. Gardeners are growing more exotic plants than ever, with banana plants – unfortunately just the ornamental, not the edible, kind – now said to be thriving in parts of Scotland. Pete Brownless, supervisor at the Royal Botanic Garden, pictured left, says rising temperatures mean plants are flowering earlier, giving beautiful blooms of greater variety.

"I think we are more likely to gain from climate change," he says, "Plants are much slower reactors to climate change and they tend to be quite adaptable as long as the change is slow.

"Twenty to 30 years ago, tree ferns wouldn't have survived outside and some species of bananas now grow in the Gulf Stream in Dumfries and Galloway. Some plants are now tending to flower earlier. Common hazels were spring flowering, but are now autumn and winter.

"Plants which are relics of alpine conditions, like the Scottish primrose, are moving further north, but we can expect to see more tropical bedding plants in people's gardens."

There's one vegetable he particularly expects to suffer from rising temperatures – but it won't bother everyone. "We can expect to see fewer quality Brussels Sprouts because there won't be cold weather to give them flavour," he says.