Climate change: the challenge for Shetland

Climate change and Shetland

We might feel that, at our latitude, a little more warmth would be no bad thing: might we save a bit of money on heating? Might we be able to grow more, bigger and better plants in the garden? Might the sea be just that bit more comfortable for swimming?

In fact, all of these are possibilities; anecdotally, faster tree and shrub growth in Shetland may already be one symptom of change. The grass-cutting and weeding season seems to have extended substantially over the last three or four decades, into October or even November.

But there are, of course, potential downsides. Warmer seas and acidification of the oceans may affect our fishing and shellfish sectors. Increases in storminess may provide even better photo opportunities but will have other less benign outcomes.

For Shetland, one of the more troubling impacts is likely to be a steadily rising sea level. This occurs partly because ice sheets and glaciers are melting and partly because the volume of water in the sea is increasing through thermal expansion.

In Shetland’s case, the issue may be exacerbated by a downward adjustment in the earth’s crust. The assumption is that, in a sort of see-saw movement, Scotland is still rebounding from the last ice age, but Shetland may still be sinking. Current predictions are that sea level will rise more in Shetland than in mainland Scotland.

Globally, the increase was 3.2mm per year between 1993 and 2010, adding up to 54mm, or more than two inches. Predictions are subject to many uncertainties, including of course how successful we are in containing global temperature rise. However, forecasters suggest that, by 2100, Shetland could experience an increase in sea levels of between 35cm and 1.15m.

That’s a wide range, but, beyond that date, forecasting becomes even more difficult, partly because we don’t fully understand the feedback mechanisms. For example, heat absorption increases with the loss of sea ice and the melting of permafrost releases methane; but the scale of these changes is as yet unknown. Nor do we know how successful our efforts at mitigation may be.

In the relatively short term, our island cousins in the Pacific face the obliteration of their homelands. In the very long term, sea levels could rise by many metres, or even tens of metres, wiping out coastal cities and dramatically altering Shetland’s geography.

A rise in sea level of around a metre may not sound very much; but coastal flooding already occurs in parts of Shetland, particularly when there’s a storm surge generated by low atmospheric pressure.

In Lerwick, vulnerable areas include lower-lying parts of the old town centre and the Grantfield and Garthspool areas. In Scalloway, flooding of properties on the main street would become more likely.

Other areas close to sea level are likely to be affected and sections of some roads could be flooded at high tide. It may be relatively easy to raise roads or car parks but protecting properties and reconfiguring infrastructure would present a more expensive challenge.

Archaeological sites have already been damaged by rising sea levels; some, such as Jarlshof, have had to be protected. Others will be at risk.

To coincide with COP26, the Shetland Architectural Society has identified eight sites around the islands in order to illustrate the implications of sea level rise. They point out that historic buildings, for example the lodberries in Lerwick or the Böd of Nesbister at Whiteness, are under ‘huge threat’.

Low-lying beaches and grasslands, for example at St Ninian’s Isle, are at risk; and there may be impacts on wildlife, in particular marine life and seabirds, arising from changes in food supply.

The Shetland response

So, what needs to be done?

Shetland’s carbon footprint is relatively high; the factors include heavy reliance – as in any rural area – on fossil-fuelled personal transport. We’re also dependent on internal and external ferry and air services and, for the moment, these too are powered by oil and its derivatives. And, of course, oil production has been a significant part of the Shetland economy for more than forty years.

New forms of heating

Domestic heating is a major source of CO2 emissions in Shetland, as it is across the UK; and at our northerly latitude, the heating season is longer than farther south.

Unlike much of the UK, though, there hasn’t been a mains gas supply for many years. Decades ago, Lerwick had a coal-fired gasworks, but it’s long gone. Bottled gas is available and is often used to fuel gas hobs, but the use of gas heating is much less common.

At present, most of our electricity is generated by an oil-fired power station, though up to about 20% comes from a combination of wind and tidal power. Some of that electricity is used for heating. Many homes, particularly in rural areas, are warmed by oil-fired boilers. In Lerwick, a district heating scheme fuelled mostly by waste, but occasionally by oil, serves many homes and public buildings.

Lowering demand for heating is fundamental. Whatever source of energy we use, it makes sense to invest in insulation so that older properties can be heated economically and we can tackle the issue of fuel poverty. New houses are well insulated but older ones will need to be upgraded.

Reducing emissions from space heating requires action by national and local government, by business and industry and by all of us as individuals. But there are some clear signs of progress.

At an individual level, there’s real interest in seeking lower- or zero-carbon solutions. Many new houses incorporate air source heat pumps and these are also beginning to be used in some older properties.

Solar energy is sometimes dismissed as a solution in Shetland, but there’s value in it. There have been some installations of photo-voltaic or water-heating roof panels; both can usefully supplement other forms of energy.

Simpler passive solutions can help, too: a large south-facing window can be useful in spring and autumn, when there may be plenty of sunshine but indoor temperatures may be on the low side of comfortable.

Wind energy is abundant in Shetland and a small wind farm at Burradale, near Lerwick, is reckoned to be amongst the most productive, for its size, in the world.

A much larger wind farm is under construction, with others proposed; these have been controversial, with concerns focusing especially on landscape impact and the release of CO2 through disturbance to peat. The energy from these farms will greatly exceed Shetland’s requirements, so most of it will be exported to the UK grid via an undersea cable, which incidentally will result in diesel generation in Shetland being mothballed.

There are also significant numbers of small aerogenerators, either for domestic or business use. In fact, the use of wind power to generate electricity has a long pedigree in Shetland, though today’s machines produce much more power than the 12 volt or 24 volt systems (known as 'windy-lights') that were used when there was no mains supply.

In Unst, our northernmost island, a pioneering ‘zero carbon house’ was constructed some years ago; it embodied all the energy saving technology then available.

But the future has already arrived, in small but important ways, in our northern isles. In Unst, ‘green’ hydrogen produced (in this case) from wind-generated electricity has been used to power a car driven by a fuel cell.

More recently, a tidal power station in Bluemull Sound, developed by Nova Innovation, is feeding electricity into the Shetland grid and also powers an electric vehicle charging station in Yell. Charging points are steadily appearing in other parts of Shetland.

There are other green shoots. Shetland Islands Council has acknowledged that there is a climate emergency and has established a Climate Change Team. One practical step has been the use of an electric vehicle to service the various council offices around Lerwick; another is the ongoing replacement of the petrol-powered car fleet used by social care staff by electric equivalents.

The council is also taking action on other fronts. It’s revising the flood risk management plan and is assuming a sea level rise of up to 1.02m by the end of this century.

And the Council has found that there’s strong public support for measures to address climate change. A council survey indicated that 82% of respondents agree that we face a climate emergency and 98.7% said that they were doing something personally to reduce their impact. Emissions from transport, our energy supply and industry were seen as the top three targets. Fuel poverty was also a priority. Ryan Thomson, who chairs the council’s Environment and Transport Committee: said:

“We are delighted with the high level of response to this important survey. Climate change is something that affects us all, and the number of people who took the time to respond shows our community’s desire to make a real difference to the issue. This is something we will be focussing keenly on as we begin to work on the ‘net-zero route maps’ for both the Council and Shetland, which will lay out our plans, projections and framework as our work progresses.”

Addressing climate change has many facets and one of them is the loss of stored CO2 from blanket bog, which is a serious concern. With Scottish Government support, efforts are being made by Shetland Amenity Trust to restore degraded peatland. Our peat bogs – which cover half Shetland’s land area – store huge amounts of carbon, but when they are damaged and dry out, carbon dioxide is released. By restoring water levels and re-planting, the decline can be arrested.

Tree planting also has potential to absorb CO2 in Shetland. Trees do grow well, given some initial shelter and protection from grazing animals. Many have been planted in recent years, but it would be possible to increase tree cover substantially.

If hydrogen is to play a big part in moving us to zero carbon, producing it in large quantities is clearly an essential piece of the jigsaw.

It was announced at COP26 that there’s the prospect of using ‘green’ hydrogen (i.e. not generated using fossil fuels) from a large floating wind farm that is proposed to be sited about 90 miles north of Unst. The Aker group intends to develop a 10 gigawatt site which, from 2030, would feed the hydrogen to a refinery in Shetland, from where it would be exported. It could presumably also be used in Shetland to replace much of the fossil fuel we presently use. The Shetland Islands Council has welcomed the plan.

A way to go

There’s a long way to go, but some important changes are on the horizon. Phasing out diesel generation of electricity will make a substantial difference. A switch away from fossil fuels in heating and transport, together with better building insulation, will be essential, too.

All sorts of other adjustments will need to be made, by all of us, if we are to help in mitigating climate change and, where we can, adapt to it.

It does seem that there’s is a strong appetite for action in Shetland; and that’s not surprising, because this is a place where life and work are intimately linked to the environment, and changes to it.