Mike Kendon
Climate Information Scientist, Met Office National Climate Information Centre
Taking systematic observations of the weather has been an important role of the Met Office since its foundation by Robert Fitzroy in the 1850s. A climate scientist and mountaineer, Mike takes a look at how temperature changes have affected the hills in Britain and overseas. metoffice.gov.uk
“At the Met Office we monitor the UK’s climate, using data from hundreds of weather stations across the country, including several mountain stations which can take observations in severe conditions. These observations clearly show that the UK’s climate is warming. All ten warmest years for the UK since 1884 have occurred since 2002. The UK has warmed by almost 1°C when we compare the most recent decade to a ‘baseline’ period of 1961-1990, and this is consistent with what is being seen globally. Human influence is clear, and recent man-made emissions of greenhouse gases are the highest in history.
“A 1°C change in temperature might seem small but this can have significant consequences in our mountain environment. At the most basic level, since temperature decreases with altitude, this represents a difference of approximately 100-150m in elevation. So habitat zones may shift to higher elevations, with those at the top being lost altogether.
“Our mountains are dominated by a generally mild, westerly Atlantic influence, and winter conditions, with ice and snow underfoot, are often marginal and transitory. A small shift in mean temperature may result in a disproportionately large decrease in days of frost or snow. In the most recent decade we have seen 16% fewer days of air frost when compared to the ‘baseline’, while widespread and substantial snow events have generally declined since the 1960s.
“The impact of climate change is particularly apparent in the Greater Ranges. During the 1990s and 2000s I was lucky enough to climb most of the major Alpine summits, and even then the effects of deglaciation were clear. Reduced snow and ice cover and increased rockfall mean many mixed Alpine climbs of the past are no longer viable in the summer. Importantly, year-round water resources provided by glaciers in the Greater Ranges are under threat.
“In the UK and worldwide, our mountains may seem enduring and timeless, but appearances can be misleading: they are a fragile environment and likely to be among the hardest hit by climate change. We must not take the services our mountains provide (not just as vital breathing space for ourselves, but also natural habitat and water resources) for granted.”