Welcome to the third of our weekly areas of focus on climate action, providing encouragement and seeking to inspire action within all the 22 Methodist Churches in the Ipswich area.
By the time the COP26 summit begins on 1st November, we will have covered 9 distinct areas of concern.
This Week’s Focus
Our focus this week is on loss of ecosystems – or more importantly, how can we prevent the loss of ecosystems and reduce the alarming rate at which species are becoming extinct.
What is an Ecosystem?
An ecosystem is a complex community of living organisms (plants, animals, other micro-organisms) sharing the same physical environment and interacting with each other. Strong interdependences between the species contribute to a rough equilibrium whose balance changes subject to common variable conditions such as weather, daylight, temperature, landscape, and local chemistry including availability of nutrients, toxins, and mineral composition.
Examples of Ecosystems
Marine ecosystems cover over 70% of the earth’s surface. Perhaps the type of ecosystem that is familiar to most people is that centred on coral reefs. The physical structure of the coral creates localised pockets with many different conditions, depending on the penetration of sunlight, the intensity of wave and current flows, the water temperature, levels of dissolved nutrient and minerals; acidity levels, and deposits of silt, sediment and decaying organic matter. These pockets create sheltered homes for some organisms, rich feeding grounds for others, and protected nurseries in which young can be born and cared for.
Alternative marine ecosystems may be defined by still water lagoon conditions in shallow water areas protected by rock reefs, or by extreme pressures at the bottom of oceans, or by the turbulence caused by wave and tide action where different temperature ocean currents collide.
An alpine ecosystem is one found in high altitude mountainous regions, where temperature cycles from daylight to night-time, short growing seasons, wind exposure, rainfall characteristics and shallow soils over impenetrable rock will be highly selective in the nature of plants which can survive.
Desert and arid ecosystems may share similar characteristics from the threat of wind desiccation, and temperature cycling, but will be widely different in nutrient availability.
Rainforests provide another unique set of conditions with the amount of sunlight penetrating the tree cover varying considerably from the canopy down to the floor. Decaying debris will build up at ground level, potentially trapping moisture, whereas high levels of humidity within the canopy will offer a very different access to water and nutrients.
Mangrove ecosystems form an important boundary between land and sea and stabilise the land reducing or preventing erosion, whilst also providing home and protection for many sea and land based animals.
Why are Ecosystems Important?
Within an ecosystem, organisms tend to form into a natural hierarchy. The strong interdependence between species means that every species within the ecosystem plays an important role in ensuring the development, relative stability and survival of the whole ecosystem. Ecosystems can be extremely complex, with many interwoven dependences, so that each ecosystem will encourage and support a unique mix of conditions, so that many rarer species may only ever be found in a single ecosystem, whereas other species may be so common that they thrive in many different ecosystems.
What is Happening to Ecosystems?
If any of the conditions influencing that ecosystem are subject to unexpected or sudden change, the balance can be so badly disturbed that one or two species can become extremely rare, or even lost completely, whilst others thrive to such an extent that they become overabundant or dominant, threatening other more vulnerable species, ultimately leading to their own extinction when they have destroyed or exhausted those on which they depend.
Changes within an ecosystem can make one or more species unsustainable, and further damage to or loss of an ecosystem can wipe-out several species, very quickly creating a mass-extinction, as the whole interdependent web of life begins to unwind. A bit like a Jenga tower when too many pieces have been removed.
Close interdependence within ecosystems is both a strength and weakness. Rare and vulnerable plants and animals may gain considerable protection and resilience from the stability provided by the other species within their own ecosystem but are easily lost if their niche conditions change.
The temperature rise of climate change is changing boundaries between and conditions within ecosystems. The increased prevalence of extreme events is exacerbating these changes, as it may be impossible for an ecosystem to recover from an extreme event, before being struck by the next extreme event.
Neighbouring ecosystems also influence each other. Melting snow and ice from a high altitude ecosystem provide much of the seasonal change in water flow in ecosystems lower down the mountains and in the surrounding valleys. Retreating ice on the glaciers threatens conditions across multiple ecosystems.
One way species adapt to change is by migrating or encroaching on other ecosystems, their presence in new regions and absence from others adds to the changing conditions within the ecosystem.
Human activity may be deliberately altering ecosystems – with economic activity in pursuit of mining, logging or clearing ground for planting of more profitable crops all driving deforestation. Not only does this shrink the geography of an ecosystem, but it also changes the conditions within the remaining area of the ecosystem – as the outer forested areas are removed, the protection they provided to the inner areas is also removed. The area which becomes the new peripheral part of the ecosystem will be exposed to greater light levels and no longer be sheltered from winds, and storms.
How Threatened are Ecosystems?
In May 2019, the UN produced a report assessing how much ecosystems were changing. The report indicated:
- around 1 in 8 of all known species (over 1m species) are threatened with extinction due to human activity;
- around 10% of all land-based species face a future with insufficient habitat for long term survival;
- more than 40% of all amphibians are threatened with extinction
- around 10% of all insects face extinction
- spread of invasive alien species has increased by 70% in the last 50 years;
- one third of marine fish stocks are being harvested at unsustainable levels;
- timber production has increased by 45% in last 50 years;
- agricultural land has increased by 50% at the expense of forests;
- around one third of forests have been lost since pre-industrial times;
- over 40% of endangered species are at risk due to invasive species resulting either from human activity or changing influences on ecosystems such as climate change;
- changing weather patterns have caused the timing of spring and autumn bird migrations to alter, affecting length of breeding seasons.
What is the Human Impact?
Biodiversity is not only important to the environment as a whole. The rich diversity of species is an important tool on which human endeavour has relied.
Over 70% of pharmaceutical medications have been inspired by study of natural species. Loss of biodiversity will make it more difficult to discover new treatments and develop new medications.
New strains of food crops have been created or selected from within the wide diversity available, so that productive yields have increased by up to three times in the last 50 years. Different strains can be selected to withstand higher temperatures, longer droughts, higher humidity, stronger winds, or more pest and disease resistant. Loss of biodiversity not only damages the environment directly, but also reduces our ability to continue adapting plants that are optimised for the new environmental conditions.
What Can We Do?
Like many aspects of the climate emergency, we may feel that we can do nothing to reduce the threat to ecosystems. When we understand the subject, we can make small differences, which ultimately add up:
- if you have garden hedges or borders, leave wild areas that encourage wild flowers, insects and birds;
- when you walk or hike in the countryside, make sure you stay on the designated paths – UK national parks have suffered in the pandemic as vegetation has been over-trampled as walkers have widened paths;
- don’t use peat composts – peatlands are an important ecosystem under threat;
- don’t lay more of your garden to hard standing than you need as it will affect drainage
- never buy goods made form unsustainable materials – be especially careful that wooden items have not used wood from areas of deforestation;
- if you choose to buy carbon offsets, make sure that your contribution is sustaining an existing ecosystem, not being used to change land use by replacing an ecosystem that might already be rare or vulnerable;
- think twice about where your vegetables and fruit are coming from – you may be supporting removal of important ecosystems so that farmers can grow non-native crops;
- always buy ethically sourced foods wherever possible – fair-trade, rainforest alliance.
Learn More.
- World Wildlife fund guidance on biodiversity
- Environmental Conscience – helpful views from an environmentalist campaigner
- UN report on loss of biodiversity
- Youmatter – a knowledge website aiming to educate in ways to change the world
- National Wildlife federation – explanation of invasive species
- Forbes report on changes to migration seasons of birds
World Environment Day Exemplar
On 5th June 1974, the first World Environment Day was marked. Every year since then, a host city has brought focus to an environmental topic that was particularly pertinent to them. The 2010 event was hosted by Kigali in Rwanda. They are home to 52 important species on the highly endangered list, including the Mountain Gorilla. As the Rwandan economy was developing. They chose to embed environmental issues throughout their development plans, unlike many countries who treated the environment as an after-thought in their planning. Their reputation made them a natural host for World Environment Day in 2010.
This Week’s Prayer
Pray for an understanding of the threat to species diversity, give thanks for all those striving to protect vulnerable environments, and elimination of practice that damages and exploits resources
Loss of Ecosystems – Key Messages
Ecosystems support the web of life and climate change threatens the delicate balance between them in several ways, including:
- accelerated species extinction
- retreating high altitude glaciers affect all lower lying terrain
- loss of arctic sea ice
- reduction of permafrost
- bleaching and death of coral reefs
- desertification risk in arid regions
- non-native species invasion stimulated by environmental changes
- seasonal migrations confused/ affected by changing conditions