ACID rain may no longer threaten the verdant slopes of Mount Snowdon but rising temperatures could present a new challenge to the fragile ecological balance in the area, according to an analysis of environmental data stretching back to 1997.
The report released today by the Environmental Change Network (ECN), a body jointly funded by the Welsh Government and the Countryside Council for Wales, paints a mixed picture of the health of arguably Wales’ most important ecosystem.
Stringent controls on sulphur dioxide emissions have succeeded in slashing the amount of acid rain which falls on Snowdon each year allowing vegetation to begin the recovery process.
The report draws on 15 years’ of monitoring environmental changes on Wales’ highest mountain, and its authors believe that shifts in temperature, atmospheric pollutants and land management are all having an impact on the mountain – beyond what could be put down to natural variation.
Despite two of the last three winters featuring heavy snowfall, the reports authors warn that: “Over the last 15 years of monitoring, the data suggests the climate has changed slightly on Snowdon – spring and summer temperatures have risen, and winters have become wetter and less cold.”
And the number of butterflies seen on Snowdon has increased over the period, an indicator of rising temperatures.
While the scientific community is largely in agreement that temperatures on Snowdon have been edging higher, there is little consensus on what that will lead to in the long run.
In 2010, Dr Alun Hubbard, a reader at Aberystwyth University’s Centre for Glaciology, warned that global warming could paradoxically lead not to more butterflies on Snowdon, but glaciers forming as the Gulf Stream disappeared.
“It could start happening next year,” he warned at the time.
“Within my lifetime we could have glaciers on Snowdon. If I live for another 40 years, it’s conceivable.”
Next page: Perplexing forecasters
In June 2011, the mountain continued to perplex forecasters by experiencing snow showers at a time when much of Wales was enduring near drought conditions.
In addition to marking changes in temperature, the ECN report also points to changes in land use which have impacted upon the environmental balance of the mountain.
“In terms of land use, there has been a major change in our uplands in general over the last 10 years including large falls in the number of sheep on the site,” it says.
“Fewer sheep grazing the vegetation has led to an increase in the amount of heather and purple-moor grass on Snowdon, and less grassy areas – a more diverse mix of plant-life which is good news for wildlife.”
The Welsh uplands are vitally important to Britain. Around 70% of fresh drinking water in the UK comes from them and the soil balance is crucial as it helps purify the rainwater which falls there.
Dylan Lloyd, one of the report’s authors, said: “As our monitoring work progresses, Snowdon ECN will continue to track changes in the climate, in airborne pollution and land management, revealing valuable information about the impact of changes on Snowdon’s natural habitats.
“Being part of a broader network of ECN sites across the UK strengthens our findings.
“We can differentiate short-term variation from long-term patterns of change, making ECN sites invaluable to investigate the health of the ecosystems we all rely on.”