UK nature feels the impact of seasonal “baseline shift” and extreme weather events as 2023 set to be warmest year on record
- 27 December 2023
With 2023 widely anticipated to be declared the warmest year on record and 2024 already forecast to be even warmer the National Trust is sounding the alarm for UK wildlife as the loss of predictable weather patterns and traditional seasonal shifts causes chaos for nature.
This year’s key weather impacts included a dry start to the year which did nothing to ease the low water levels caused by last year’s low rainfall with areas in the south west of England and east Anglia remaining in drought for over 12 months (until September).
In the summer, the UK recorded its warmest ever June. The river Derwent in the Borrowdale Valley in the Lake District (traditionally the wettest area of England) dried out for the third consecutive June, and sea temperatures reached new highs – with scientists clocking temperatures 3 to 4C warmer than usual particularly on the north-east coast of England and Scotland and north-west Ireland.
July was also the hottest month ever recorded globally, 1.5C warmer than average with global air and ocean surface temperatures also setting all-time records.
Autumn was warmer and wetter than average with huge levels of rainfall particular in October retipping the balance and two extreme weather events - storm Babet closely followed by storm Ciaran - battering parts of the country causing serious flooding which impacted people, nature, landscapes, properties and coastlines.
One area of the Dorset coast, cared for by the conservation charity, suffered up to 15 years’ worth of erosion in just one day, after Ciaran hit the country’s southern shores.
Ben McCarthy, Head of Nature and Restoration Ecology at the National Trust said: “The shifting weather patterns we’re seeing in the UK, particularly with the warmer temperatures we’re experiencing is continuing to upset the natural, regular rhythm of the seasons, causing stress to wildlife and making it more susceptible to pests and disease.
“This loss of predictability causes chaos for the annual behaviours of animals in particular, but can also impact trees and plants.
“The warmer year-round temperatures are resulting in shorter winters which could have particularly devastating impacts for trees – with cold snaps just not long enough to kill off diseases such as oak processionary moth, whose caterpillars infest oak trees, leaving them vulnerable to other threats. The spread northwards through Europe from their traditional home in the Mediterranean is a tangible consequence of our warming climate.
“Warmer winters could also impact our heathlands, allowing the heather beetle to take hold killing off huge swathes of heather.
“It also impacts hibernators like dormice, which may emerge from torpor (hibernation) early using up vital energy stores, and red deer may leave rutting to later, meaning calves are born in the summer rather than the spring, with insufficient time to grown and put on fat reserves to survive cold snaps.
“It’s these baseline changes that we’re seeing that are really worrying and what we should be taking more notice of, particularly when combined with extreme weather events, which makes things even more challenging.”
Some of the simplest seasonal shifts noted by rangers and gardeners around the Trust, include mowing grass much later, up until late November, due to grass ‘not shutting down’ because of the warm and wet conditions.
These warm temperatures have also resulted in some shrubs budding for a second time or coming into bloom early making them susceptible to sudden cold snaps, reducing flowering in the spring and summer months with knock on impacts for pollinators and seed set.
“The incremental shifts we’re experiencing in terms of our seasons extending may not feel like much in a 12-month period, but over a decade the changes are extremely significant,” continued Ben.
“It demonstrates how vitally important it is to continually assess local conditions to ensure that we have the right conservation plans in place to help nature adapt as we begin to see climate change starting to bite.”
The Trust also experienced the impact of warmer temperatures and low water levels on water with algal blooms occurring in the Lake District as early as January, but also at Port Stewart, on the coast of Northern Ireland, over the summer.
Ben continued: “Sea surface temperature records have also been broken, and in a big way. We are acutely aware of the risks rising temperatures could have not only on the marine environment but on streams, rivers and lakes across the country with increases impacting all river life. One especially worrying result is more instances of algal blooms, which are more likely to grow when a water course is in poor health, covering the water surface and suffocating the ecosystem.
“The increasing temperatures we’re seeing combined with more water pollution and/or damaging sewage outflows, is a recipe for disaster for not only nature, but humans too.”
Keith Jones, National Climate Change Consultant at the National Trust said: “When you consider the extreme temperatures and heatwaves that have devastated parts of Europe and other countries this year, we have been extremely fortunate. We were just 1,000 miles away from experiencing a second year of serious drought and record-breaking temperatures which would have had huge consequences for nature, people and food production.
“But, we can’t allow ourselves to be lulled into any sense of false security. In the near future we are likely to experience a combination of drought and high temperatures as well as high rainfall and flood – and we need to get ready for this new ‘norm’. Water is going to be key – not having enough and also not too much.”
To help deal with the unpredictability of both the seasons and the weather, and to tackle the climate and nature emergency, the Trust has been working hard to make its landscapes more resilient, and able to adapt to these shifts.
Two key projects it has completed this year to meet the challenges of the climate and nature crisis includes its ‘Stage 0’ river reset project on Exmoor in Somerset on the Holnicote Estate, and its work to create 10 hectares of new saltmarsh habitat at Northey Island in the Blackwater Estuary on the Essex coast.
Ben McCarthy continued: “At Holnicote we literally saw more nature move back in, within just three months of the project’s completion as this new complex waterscape started to ‘bed in’ and thrive.
“The new saltmarsh habitat at Northey Island will benefit both people and wildlife. It will absorb some of the force of the waves, providing a flood defence, whilst also sequestering large amounts of carbon and will also offer great new habitat for plants including the nationally scarce shrubby sea blite, golden samphire and bladder rack and birds such as dark-bellied brent geese, dunlins, redshank and ringed plover.
“By viewing the climate and nature crisis as two sides of the same coin, we know projects to help tackle the climate crisis, will also benefit nature too – and that once we create the right habitats for nature to thrive – nature will move back in and we can see signs of recovery relatively quickly.
“We therefore need to see more action from politicians throughout the country – particularly as we enter this election year to ensure tackling the nature and climate crisis is a top priority.
“We want to see parties commit to accelerating progress on nature restoration, increase support for nature-based solutions to climate change and to put climate adaptation at the heart of their manifestos, so the UK can be better prepared for the weather extremes we will increasingly experience.”
Key habitat news at National Trust places in 2023
Rivers, lakes and coast
With much of the country continuing to feel the impacts of low rainfall and remaining in drought for much of the year, more needs to be done to make the landscape more resilient to climate change.
October retipped the balance with huge rainfall figures. Some catchments in the east of England saw 366 per cent of their long-term average rainfall, and 12 catchments recording their wettest ever since 1871.
Water experts at the Trust said this ‘hangover’ from 2022 meant some sites spent the year recovering, with the impact on wildlife populations yet to be fully realised.
Stewart Clarke, National Specialist, Freshwater, catchments and estuaries said: “The effects of drought are cumulative. We can deal with one ‘bad’ year, but it’s the combined effect of several years of drought that is going to have lasting and serious consequences for wildlife populations.
“Just like farmers need certain ‘windows’ each year to harvest crops and manage and rotate livestock, we are struggling to plan conservation work, as periods of stable weather conditions are being squeezed into ever shorter spells.
“The high-water levels we’ve seen across the country in our rivers and lakes will undoubtedly have caused issues for some species such as water voles, who would have been driven from flooded burrows leaving them exposed and at increased risk of cold, hunger and predation.
“With our rivers increasing constrained within their banks, flood waters are unable to spill out onto naturally functioning floodplains increasing flood risk to our towns and cities downstream and ripping out habitat as flood waters scour out river beds and banks.
With 14 per cent of English rivers in poor health due to pollution, the Trust also experienced issues with algal blooms in some areas. The blooms which float on the top of the water, block out sunlight and, when the blooms die, reduce oxygen levels suffocating fish and other aquatic wildlife.
At Bassenthwaite Lake in the Lake District, low water levels and a lack of rainfall resulting in less water flowing through some catchments, meant blooms were spotted as early as January.
Lake Windermere also experienced similar issues in June as did Lough Neagh in Northern Ireland, which then consequentially impacted a stretch of the beach/coastline along Portstewart Strand, cared for by the National Trust, as the water carried the blooms through the catchment from the Lough to the sea.
The very wet July and a warm and wet August, following on from two record breaking years for temperatures, combined with more nutrients in the system resulted in increased growth of the cyanobacteria which form the blooms.
Algal blooms do occur regularly on Lough Neagh but it was the extent of this most recent bloom that has been disturbing.
Climate and Environment Adviser at the National Trust in Northern Ireland, Sean Maxwell explained: “With a warming and more turbulent climate we are seeing longer growing periods for the cyanobacteria and less time for the lough to fully recover from these events, which is priming the lough to see algal bloom events at this scale on a more regular basis.
“Warmer spring months meant the cyanobacteria’s algal blooms were making an appearance across NI water ways from as early as May and levels of the bloom reached unprecedented levels when the lough reached a record 17.4C in June.
“The blooms only started to reduce when temperatures and rainfall dropped in late September. Natural wave action also helps to break up the blooms, so the presence of algal blooms along the coast is heavily dependent on the tides and other weather factors.
“This issue is going to continue as we see more warm and wet weather due to climate change. To help us tackle future issues we need better catchment management as well as reducing pollution from both agricultural fields but also overflows from waste water treatment too.
“This is an example of how all our waters are connected and how an issue from the centre of Northern Ireland can spread through the rivers to the coast.”
Storm Antoni resulted in in a month of rainfall falling in some areas of the country in August – toppling some trees, but it was the two autumn storms – Babet and Ciaran that caused damage to National Trust places.
Storm Babet left a trail of destruction across landscapes, houses and gardens cared for by the National Trust, throughout the spine of England in October.
The persistent rain caused water levels to rise across much of the country, impacting properties in the Midlands and north-east of England.
At Cragside in Northumberland, water levels in the River Coquet rose from its typical 0.4 metres to 3.27 metres, and this together with the sheer volume of water temporarily overwhelmed the Archimedes Screw, installed to generate hydro-electricity, to stop working.
In the Peak District a deluge of water rushed down the hillsides and overpowered river networks causing flooding and eroding hundreds of metres footpaths and damaging fences, walls and bridges; and at Carding Mill Valley and the Long Mynd in Shropshire, the volume of water eroded away some of banks of the Ashbrooke river.
On the Wallington Estate in Northumberland, when close to 10cm of rain fell over 48 hours, the River Wansbeck spilled over onto the River Walk causing both bank and path erosion.
At Charlecote Park in Warwickshire, a 260-year old Cedar of Lebanon, fell and at Attingham Park in Shropshire the floodwater blocked access and the River Tern burst its banks creating a temporary ‘lake’ flowing through the parkland.
One of the consequences of the storm that is just coming to light is the possible impact on the population of the Shags who live and breed on the Farne Islands. The team has noted that there are hardly any birds in the winter roosts on the islands, with a number of dead birds being washed up on the islands, attributing this to possible losses of the birds due to storm Babet which is likely to have disrupted their ability to feed.
Farne Islands Ranger Tom Hendry explains: “The Shags tend to stay local around the islands and east coast all autumn and winter. This is because they prefer to fish in shallower waters, around sand banks and tidal fronts. They typically dive to around 30m.
“This ‘localism’ makes them very susceptible to storms and turbulent waters – and due to the stormy weather, it has been too rough for them to fish effectively. They also do not store much fat - and because they don’t have waterproof feathers, they need to dry out their feathers regularly. We believe that this has caused starvation among birds on the east coast. It could be that other factors play into it, but the weather is the main issue.”
Ciaran ravaged parts of the Dorset coastline, gouging away five years’ worth of beach across the course of two high tides at Studland. At Hive Beach the lower wall protecting the car park was breached for the first time and along the coast at Cogden, the waves crashed over the shingle spit to the reedbeds behind carving out a deep, wide channel as it retreated through the spit.
Commenting on the levels of erosion seen, Ben McCarthy added: “Ciaran created coastal change at three of our places at a rapid pace.
“It was like a starting gun going off, and now these breaches have happened, it’s likely erosion will accelerate much more quickly.
“The damage we sustained is a clear indication of how the frequency and intensity of storms together with rising sea-levels is likely to accelerate erosion and will require us to look at how we adapt and change how we care for the sites to cope with future impacts.”
Trees and woodlands
Trees of all ages were also impacted by the lack of moisture in the ground until the regular rainfall returned in July.
These conditions meant trees were constantly under stress – with symptoms in some instances being a second consecutive mast year for some trees producing significant crops of berries and nuts in some areas of the country, due to not having the opportunity to ‘rest’, and the continuing impact of diseases such as oak processionary moth, which has become established due to the warmer year-round temperatures.
However, in better news, this year has been a better year overall for establishing new saplings – with fewer losses than in 2022 due to the improved warm and wet growing conditions, particularly during the second half of the year.
John Deakin, Head of Trees and Woodland at the National Trust said: “Our trees are under threat from a combination of factors, but we are determined to play our part in planting and establishing the millions of trees needed to tackle the nature and climate crisis.
“Establishing new trees is obviously very challenging in periods of drought – and last year was really difficult with up to 80 per cent of saplings dying in some areas of the country due to the drought (EofE) - therefore we need to be inventive in our approach to maintain the moisture levels in the soil.
“A couple of ways we can do this is through wood mulching, but we’re also finding wool mulches using sheep fleeces, can be really effective.
“As well as helping to retain moisture in the soil, they also prevent grass growth around the base of the sapling, which means there is not so much competition for moisture.”
The Trust is also carefully selecting native tree types for its different projects by projecting ahead to the climate conditions we may be experiencing in 50 years’ time.
John continued “When selecting trees we are encouraging our properties to match their tree selection to provenances which will suit the predicted new norm. We need to adapt and select the species which are most likely to thrive.
“For example, beech trees and woodlands are traditionally thought to be better suited to the south of England, but it’s likely in future that they will be better suited further north. And, lime trees, currently under-represented across the country, are likely to do better in a warming climate.
“Our traditional thinking of where certain species like English oak (Quercus Robur) and Sessile oak (Quercus Petraea) may thrive geographically is also likely to change as we are already seeing the huge impact of Acute Oak Decline on English oak in the south east and midlands, previously their stronghold, now being compromised.
“This is all about thinking through the changes we’re likely to see and planning and planting a wider variety of tree types, mixing things up to improve tree diversity and to build resilience.
“We are aiming to assist what nature, if given time, would naturally try to do. But given that time is against us, when it comes to tackling climate change and the nature crisis, we need to act now.”
Species – winners, losers and mixed findings for 2023
Record-breaking numbers of Cornish Choughs spotted in Cornwall – a 60% increase in the numbers of chicks on last year. (2023 figures - 39 breeding pairs and approx. 112 chicks vs 2022 figures 25 breeding pairs, raising 71 young).
Previously extinct in Cornwall, the successful spread of the population on the Roseland peninsula and north of the Camel Estuary is due to the collaborative efforts of RSPB, National Trust, Natural England, Cornwall Birds (CBWPS) working with nature-friendly farmers to improve conditions and monitor nests throughout the breeding season.
For the first time the beavers living in the second beaver enclosure on the Holnicote Estate in Somerset at Whitemans in Somerset had their first kits. Twins were born there with another kit born to the parents at Paddocks, the fourth kit born since a pair of adult beavers were introduced in January 2020.
A family of four beavers were successfully introduced on the Trust’s Wallington Estate in Northumberland in July. Since their introduction the family has settled in well already constructing several dams, including one measuring 4-feet high, creating a new pond.
Staff at the property said they had been “blown away” by the changes. Kingfishers, small fish and dragonflies have since been spotted in the rapidly changing habitat, and staff hope the frog population will soon benefit.
In October, Storm Babet brought heavy rainfall to the property, damaging four of the beavers’ dams. But rangers noted that the industrious family had been quick to start repairs after the storm.
At Formby in Merseyside, rangers recorded the first natterjack toadlets since 2020 in May.
Bree Hodge, Ranger explained “The Sefton Coast is one of the most important dune habitats in North-west Europe and is home to 40% of the UK’s natterjack population. In recent years natterjack toads have successfully spawned. However, dramatic changes in typical seasonal weather patterns have caused the breeding slacks or pools to dry out too quickly, before the tadpoles completed metamorphosis into a toadlet.
That’s why as part of the Nationwide Dynamic Dunescapes project we’ve been restoring existing pools and creating new ones. This stepping stone network of 26 pools, with different depths and conditions, means natterjack toads now have more options to help them cope with increasingly unpredictable weather conditions.
The Sefton Coast is one of the last strongholds for natterjack toads so it’s crucial we continue doing everything we can to future proof this habitat and boost their chances of survival.”
Black oil beetle
The rare black oil beetle was spotted at Kinver Edge in Staffordshire for the first time in nine years in a regionally significant discovery.
The sandy soils of lowland heath suit many species of burrowing insects, including solitary bees, whose nests and eggs the oil beetle feeds on.
National Trust Countryside Manager Ewan Chapman explains: "These beetles make their home in sandy soils by digging nest burrows into bare earth, which is a key characteristic of heathland habitats.
“The discovery of the beetle is a good indicator that our work to restore the heath on Kinver Edge is really paying off."
The rain in July and warm, wet conditions which continued into the autumn were ideal for waxcap grassland fungi and surveyors noticed a very early start to the season, which was much needed as the previous two years were dry late into the season and meant that many early fruiting species missed their opportunity.
Ancient grassland surveyor Steve Hindle, based in West Yorkshire, noticed several very rare species making an appearance this year, and found that conditions in general were ideal for species belonging to this habitat – one of the most threatened habitat types across Europe.
A species found in West Yorkshire was sent to world experts for analysis and found to be the first record for the UK. The Dark Velvet Fanvault was first spotted by Steve in 2021 and was discovered again in August this year at Hardcastle Crags, a National Trust estate. This small, brown mushroom is likely to have been in the UK for centuries but has not been recorded before.
Surveys also took place in the Yorkshire Dales and finds included Glistening waxcap, Jubilee waxcap and Butterscotch Waxcap, which are all rarities. Other discoveries were made in the Lake District, and in the Peak District, where another unusual find, the Contorted Strangler (Dissoderma galerinicola) – which parasites another species – is believed to be the first record in England.
Mosses and liverworts
Some of the rare lichens and liverworts that grow in the temperate rainforest at Lydford Gorge, on the edge of Dartmoor in Devon were hugely impacted by last year's drought, the dry winter and dry start to the year, and have unfortunately died.
These lichens and liverworts get their water from the air (they have no roots). They can sometimes recover, but despite the higher levels of rain since July, they don’t appear to have survived.
Demelza Hyde, lead ranger for the National Trust at Lydford Gorge said: “We’re seeing dead patches of common and nationally and internationally rare and important species of mosses, lichens, and liverworts such as greater fork moss, holt’s mouse-tail moss, floury dog lichen, stinky sticta’s and hutchins’ Hollywort on the rocks, boulders, woodland floor and trees adjacent to the river which is normally very humid. Typically mosses and liverworts trap moisture and can release it very slowly, helping with humidity levels. However, what we’re seeing is a vicious circle where there is less water, less humidity, more plants get effected.
“These bryophytes are vitally important. They are some of the oldest land plants to exist on the planet and over 400 million years old. They would have been here when the gorge was created 11,500 years ago – although they are not individually that old. They are often the first species to colonise an area, producing the debris which other things like trees can grow in. They also provide the slopes with a certain stability, but when these areas dry out, there is an increasing risk of landslides.”
Bird flu returned to the Farne Islands this year, proving fatal for a range of seabirds.
Worryingly it spread to five more significant Trust sites for breeding seabirds around the UK, including Brownsea in Dorset, Cemlyn in north Wales and Long Nanny in Northumberland.
Long Nanny is home to Britain’s largest mainland colony of Arctic terns as well as a small colony of little terns.
James Porteous Area Ranger said: “At least eight per cent of the breeding population of Arctic terns died over the summer, along with around 40 per cent of the chicks. This is incredibly worrying, especially considering that these fragile seabirds are already having to deal with the impact of climate change, and could take years for the colony to recover.”
On the Farne Islands, the rangers took quick action once it appeared the disease had returned, picking up any dead birds in efforts to limit the spread of the disease.
This approach did appear to help with the number of dead birds down 39% on last year. Different birds were impacted too with the most fatalities across the kittiwakes, herring, lesser black-backed gulls and Arctic tern populations compared to guillemots, kittiwakes and puffins in 2022.
Area Ranger Harriet Reid said: “We’re hopeful that perhaps immunity is building in some species and populations already impacted by the disease.
“We need to rapidly understand what more we can do to protect these precious seabirds and are in a race against time to carry out the necessary research to inform how best to conserve these magnificent birds.”
There was a glimmer of hope at Blakeney Point in Norfolk where the little tern population remained largely unaffected by bird flu, with 49 chicks recorded, the highest numbers since 2020.
Observational data of the Red deer (Cervus Elaphus) calving (birth) dates seem to indicate that Red deer rutting behaviour is extending later into the winter on the Holnicote Estate on Exmoor. The change in rutting times is supported, in-part, by recent research carried out by the Isle of Rum Red deer project.
Simon Powne, Wildlife Manager at the National Trust on the Holnicote Estate said: “We only have two species of native deer in the UK, Red and Roe deer.
“The consequences of later rutting within the wild deer herd is that the calves are then born later in the year – so in the summer rather than the spring. This means they don’t necessarily have the time to grow and put on the weight and fat needed to survive over winter, especially if the weather is harsh.
“We intend to focus on gathering the necessary data over the next few years to quantify this further and to better understand what these changes could mean for this special species.”
Dunwich Heath in Suffolk is usually a blanket of purple. However, in 2022, the summer’s drought, extreme heat and high numbers of heather beetle killed much of the heather.
An infrared drone survey completed this summer revealed a 60 per cent loss in heather, and while the rains that came in late summer do seem to have allowed for some recovery, rangers estimate that around 40 per cent of the famous heathland is unlikely to recover.
As well as regular restoration efforts, the rangers will be completing additional heather regeneration trials this winter to explore which combination of management techniques lead to the quickest and most effective ways to rejuvenate the heather in areas of total die-off.
Area Ranger Sam Cooper said: “Hopefully if we can avoid another drought next year we will have another year where we’ll see some recovery. This along with the heather regen(cutting) trial this winter should hopefully lead to further improvements.”
Where there is significant die off in the heather, there is also a lower number of insects (particularly pollinators), which in turn means less food for the birds. Without enough of an on-site food source, many bird species may not attempt to nest at all or will fail during nesting.
Dunwich is an important site for rare Schedule 1 species such as the Dartford warbler - which is a UK Lowland heath specialist and does not migrate - and recorded numbers in 2023 have dropped from 30 breeding pairs to under 20. While the ratio of Dartford chicks that fledged wasn’t too poor, the overall number was lower than most years due to fewer pairs breeding in the first place.
Butterflies and moths on the whole seem to have had a better year than expected, considering last year’s drought – and once the temperatures did start to rise in the spring there were good sightings and numbers across many National Trust places particularly in the south of the country.
Of particular note was the success of the Heath fritillary butterfly on the Holnicote Estate on Exmoor in Somerset. Staff noted record-breaking numbers on parts of the estate, and individuals being found at new sites, or sites which they had previously been thought extinct.
One site had over 500 individuals recorded in a two-hour survey. The weather played its part in promoting good numbers this year. A warm, sunny period of settled weather coincided with the fritillaries’ flight period, which provided perfect conditions for the adult butterflies to emerge and breed.
The species is known to have a ‘Boom and Bust’ cycle. Making use of good conditions some years, and persisting in lower numbers in others but the team are confident in their efforts to promote a sustainable population.
The team at Collard Hill (also in Somerset) were also pleased to record that numbers of the rare Large Blue butterfly were also good – which had been a worry as they have a slightly unusual lifecycle in that once their larvae have finished feeding on the flower heads of wild thyme they turn into carnivores – and live and feed on ant grubs in red ant nests.
This was in contrast to the fortunes of the grizzled skipper at Calke Abbey in Derbyshire. The team here reintroduced the grizzled skipper with Butterfly Conservation in 2019 with eggs and adults transferred from a donor site in Warwickshire. There was a subsequent second phase but the planned third phase was thwarted by weather which had impacted on the donor population meaning it couldn’t go ahead.
Carl Hawke, Nature Conservation Adviser at the National Trust explains: “We had hoped the original two phases would be sufficient, but numbers never picked up.
“This year the combination of the very hot and dry June which frazzled the wild strawberry plants which the caterpillars feed on, followed by the wet July - when the adults would be flying –almost certainly resulted in the loss of this newly reintroduced population.”