Climate change: a local perspective

Last week I had a call from a local journalist who was researching an article on the signs and symptoms of climate change. In particular he wanted to know how global warming is effecting animals and plants in the Sheffield area. He also asked me for my personal impressions about how the climate is changing locally.

Hurricane Epsilon from the International Space Station.
(Photo by NASA)

I was a little apprehensive about making general statements that I couldn't immediately back-up with hard evidence. I don't dispute the evidence for man-made climate change, but I'm conscious that interpreting and predicting the local effects can be a bit of a minefield.

The UK's weather is notoriously difficult to predict, even in the short-term. The Earth may be getting warmer, but it doesn't necessarily follow that the British Isles will end up sizzling. Besides, our climate is constantly fluctuating. On a local scale it can be extremely difficult to separate man-made trends from naturally occurring variations.

Hummingbird hawk-moth - an increasingly common sight.
(Photo by Matt Savigear)

Journalists have an unfortunate tendency to make complex issues simple (and, perversely, simple issues complex) so I was rather guarded with my answers. I told him that the most obvious changes in our local wildlife so far have been the increased sightings of insects previously found mainly in warmer climes. In recent years the hummingbird hawk-moth (Macroglossum stellatarum) has become a regular visitor to local gardens. Several species of dragonflies from southern Europe turned up in our region this summer.

Long-tailed tit - doing well, thanks to mild winters.
(Photo by Steven Joscelyn)

I also mentioned that milder winters (coupled with other factors) have led to a steady increase in the populations of some small  birds, such as the long-tailed tit (Aegithalos caudatus), which struggle to survive in prolonged cold spells.

When it came to my personal impressions of climate change I was less guarded. I have noticed local climatic changes within my lifetime. The winters in Sheffield are less severe now than they were when I was a child in the 1960s. Heavy snow falls are less frequent. It is 10 years since our last 'big freeze' and 25 years since the city was truly snowbound.

Autumn in the Rivelin Valley - leaf fall seems to be getting later.

Spring usually arrives earlier now and autumn seems to be getting later year by year. As I write, in mid-November, the woods of the Rivelin Valley are resplendent in their autumnal foliage; it looks like it could be another two weeks before all the leaves are gone. My recollection is that, in my childhood, most trees had lost their leaves by the end of October. I recall being taken to see Sheffield University's Rag Parade in the 1960s, an event that took place each year on the last Saturday in October. The tree-lined streets around the student halls of residence were always choked with fallen leaves.

Towards the end of the interview, the journalist made a suggestion along the lines of "so global warming may not effect Sheffield too badly then, and we might see some unusual wildlife to boot". Much as I hate to be the harbinger of doom, I reminded him that we are only in the earliest stages of climate change and once it really begins to bite it will threaten the lives and livelihoods of millions of people around the world.

Us Sheffielders may joke that our city is so hilly that we have nowt to fear from rising sea levels, but the mass displacement of people from low-lying regions is likely to have dramatic knock-on effects wherever you live.

In my view climate change is inevitable. Even without human-induced trends, the global climate is far from immutable in the long run. After all, it's less than 20,000 years since northern Europe was locked in perpetual winter. Since the end of the ice age the climate of the British Isles has see-sawed between warm and cool, wet and dry.

For me, the key questions are:

1. What form will climate change take - fry or freeze?

Current thinking seems to be that although the Earth is in an interglacial period, man-made warming is likely to hold sway over natural cooling.

2. How rapidly will the change happen?

From an ecological perspective, the rate of climate change is critical. If it happens too quickly, some plants and animals will be unable to adapt. This is likely to be more of a problem for organisms with long life-cycles (e.g trees) than those with short life-cycles (e.g insects).

3. How effectively can mankind manage the change?

Within the scope of 'managing the change' I would include:

• reducing emissions of greenhouse gases;
• seeking technological solutions;
• preparing for the long term consequences of climate change.

All of these will require international co-operation on an unprecedented scale - but are we up to it?

Although it wasn't a meteorological phenomenon, the catastrophic tsunami of December 2004 gave an inkling of the scale of humanitarian disaster that could result from rising sea levels. Eight months later, the chaos and destruction caused by Hurricane Katrina demonstrated that even the most powerful nation on Earth cannot yet effectively safeguard itself from the impacts of extreme weather.

A wake-up call, surely?

Comments

[MinorRipper]

Here's an article on Prince Charles' recent green initiative. Kudos for him at least attempting to raise awareness of global warming...
www.minor-ripper.blogspot.com

[Pete M]

Good stuff.

I've written something for the next SWT magazine on this subject, wish I'd have read this first!

[Jess]

Roger...why do I have this sneaking suspicion that one day I'll see you on TV being very respectable and serious, and I'll be stuck with.."well, well...I knew him (sort of) when he and Simon discovered each other again by way of blogging!!"

[Aydin]

A well written piece, Roger.