Climate change refers to the long-term shift in weather patterns across the world.
It’s been largely driven by human activity, mainly through the burning of fossil fuels but also through deforestation and intensive agriculture. Global warming poses a huge threat to biodiversity, and further animal and plant extinctions worldwide are predicted as habitats and conditions change faster than a species can adapt.
The UK and climate change
Climate change is expected to result in warmer winters and summers, with a study from 2010 highlighting that in the UK, spring is arriving 11 days earlier when compared to 1976.
Changes in temperature and rainfall, combined with extreme weather events (such as Storm Ciara in February 2020 when extreme winds resulted in the closure of all our parks) are a threat to habitats and wildlife, and present challenges for the management of open spaces. For example, the Met Office described 2020 as:
“a year of extremes with the wettest February on record, the sunniest spring, a heatwave in the summer and a day in October breaking rainfall records.”
How climate change affects nature
Changes in weather and breeding patterns are just a few of the effects that climate change has on the natural environment and wildlife at the Royal Parks. Some of the impacts posed by climate change are described below.
Extreme rainfall can damage habitats
Rain was an almost daily presence in the first few weeks of 2021, causing rivers and streams in the parks to swell and resulting in some localised flooding. The ground became so saturated that some areas were transformed into mud baths. This combined with high visitor numbers and people spreading out in the parks to socially distance, meant the landscape incurred some significant damage with footpaths widening and adjacent habitats trampled.
To address this and to #HelpNatureThrive, we are undertaking a project to reinstate damaged footpaths and protect and restore vulnerable habitats, such as acid grasslands and their ant hills.
Dry periods can harm great crested newts
In contrast, a prolonged period of low rainfall last spring resulted in water levels dropping considerably in some ponds, negatively impacting amphibians. Of particular concern, was the rare and protected great crested newt as low water levels can male it difficult for the newts to perform their courtship displays and successfully lay their eggs, with many ponds drying up before eggs had time to hatch or for the juveniles to mature and leave the pond.
In the long term this will impact amphibian populations by reducing breeding success, potentially even causing localised extinctions.
Recent research led by ZSL, University College London and Queen Mary University of London found that global warming has also increased the spread and severity of a fatal amphibian disease caused by Ranavirus which has impacted common frog populations in the parks and throughout the UK.
On land, prolonged dry periods in the summer can impact important food sources for species feeding on soil invertebrates. Hard and sometimes compacted ground can be impenetrable for species such as hedgehogs, blackbirds and thrushes trying to access those vital sources of food.
Invertebrates are emerging earlier
We know climate change is causing many invertebrates to emerge earlier or to alter their distribution (typically expanding northwards or to a higher altitude).
It’s a delight to see some new species colonising the parks, such as willow emerald damselflies in Richmond Park and Bushy Park, and interesting to observe buff-tailed bumble bees surviving the winter in Kensington Gardens – certainly a result of warmer temperatures in the city and the availability of winter flowering plants in the park.
However, other species adapted to cooler conditions are undergoing contraction in their ranges. And as species respond to environmental change, the interaction between them may also alter including those important predator-prey relationships. For example, the egg hatching time in some birds is falling out of sync with peak caterpillar abundance – meaning a reduction in the availability of a critical food source.
Herons are breeding earlier
Our Conservation Officer, Tony Duckett, has been observing wildlife for decades and has noticed significant changes in the parks’ bird populations.
For example, the Cetti’s warbler, an insect eating bird, has been spreading northwards through Europe since the 1970s. Finding insects during the winter can be hard and a sudden cold snap can kill a large percentage of the birds in the UK. Three of the Royal Parks have had pairs of Cetti’s warbler breed and overwinter, with Regent’s Park being the most recent site to host this bird.
Another species, the willow warbler, was once commonly found in the south of England in spring, but climate change has meant that the life cycle of the invertebrates in the South is too advanced by the time they arrive, and so their range seems to have shifted further north towards cooler woodlands. The lifecycle of the invertebrates they feed on may have only shifted by a week or two, but for a bird that only has one brood the timing of the food supply is critical.
As our winters have become milder with fewer cold spells many birds are breeding earlier including the grey herons in The Regent’s Park. The majority of nests now become occupied by mid-February, but this winter, one pair was spotted incubating eggs as early as December! Early nesting can be risky as food resources may not be sufficient for the survival of offspring, and a sudden cold spell with frozen, inaccessible water would prevent the adults sourcing food for them and their young.
The effects of climate change on trees
Trees play a key role in climate change mitigation, absorbing carbon dioxide and producing oxygen. They also reduce the city’s temperature and help reduce flooding. Research by Treeconomics, demonstrated that Hyde Park removes 2.7 tonnes of pollutants each year including carbon dioxide.
However, trees are impacted significantly by climate change. We have over 170k trees across the parks, and the effects of global warming on them are becoming increasingly more obvious. Heavy rainfall can lead to waterlogging of sites, which can damage or even kill trees. Warmer conditions can lead to an increase in pests and diseases such as oak processionary moth, and drought stress in periods of prolonged low rainfall weakens trees, making them more susceptible to attack and damage from these pests and diseases.
Changing weather patterns also disrupt the established development of tree species. For example, late frosts may disrupt flowering and leaf bud burst, whilst trees in full leaf are at greater risk from an increase in unseasonal storms.
How can we help mitigate the effects of climate change on nature?
We all have a role to play in counteracting climate change; for example, reducing our energy use, reducing or eliminating our use of single use plastic, making thoughtful and informed purchasing decisions and by supporting nature in our local area.
As well as protecting existing habitats, the Royal Parks is working to deliver a range of habitat improvements across the parks. This includes the addition of lakeside habitat, the creation of refuges for birds and invertebrates; improving water quality; the expansion of wildflower meadows and increasing areas of longer grass (which is less prone to moisture loss); reducing bracken encroachment on acid grassland, managing pests and diseases in trees, and the sensitive management of dead and decaying wood to ensure the complex communities of fungi, lichens and invertebrates they support will flourish.
Visitors to the parks can help nature by supporting our ‘Help Nature Thrive’ campaign where we encourage people to learn about nature, to #LeaveNoTrace on their visit and #KeepWildlifeWild by not feeding or touching animals.
Find out more about how you can ‘Help Nature Thrive’ and help counteract the effects of climate change on the natural environment.