At this point in the history of the universe it is necessary to introduce a few ecological terms to help explain how we are all connected to the environment in some way and that even the most dedicated city-dweller relies on the natural world. We are animals and we need a healthy environment around us to survive. Without forests, healthy oceans, clean water and a thriving, biodiverse ecosystem the human race would not be where it is now.
Ecology deals with the interrelations of all organisms (C Krebs, 2008). Humans have had the greatest influence of all animals on the land use of the planet’s surface, with over 50% changed by our use into cities and agriculture, replacing once diverse natural terrains. Many species are lost when ecosystems are destroyed as species are generally only able to live where they were adapted. However, there are also many plants that do far too well in other places and these may become rampant environmental weeds.
Biodiversity is the number of living organisms, plants, insects, birds, and other life forms in a specified area. In natural systems there is usually high diversity, giving resilience to the system with a good balance of pollinators, pests and predators, plants and decomposers and other organisms. As we remove types of plants and animals from a system it begins to affect how the ecosystem functions, making it less resilient to changes in climate, from wild fire or other of the now more regularly occurring natural disasters. Beyond a certain point these systems become less able to cope with damage, they lose their resilience, the ability to repair themselves and stop performing as a stable ecosystem. This can allow changes of species composition as weeds or other feral species encroach, reducing and often replacing the natural diversity.
There may be keystone species that have a major influence on food webs in an area. This may be a top level predator in the African savannah or the tiny algae that feed krill in the Antarctic oceans, tiny green organisms that power whales and many thousands of fish in the sea. Disturbing the numbers of the keystone species can disrupt other levels in the food web, changing populations.
While some natural resources can easily be replaced with a similarly functioning or visually similar ecosystem, the lack of biodiversity gives less options or resilience for ecological recovery should something go wrong eg wildfires, droughts, floods?
A given ecosystem can only support a certain number of organisms using it. Since the planet overall is a group of ecosystems working together we can consider whether the human race is able to keep living on the planet and consume the current amount of resources that we do. The short answer is No. World Over Shoot day happens earlier each year. (www.overshootday.org)
Everything we use comes from nature or been discovered in nature and had a chemical copy made in a laboratory, such as for medicines based on plants. Ecosystem services refer to the collective process through which the planet’s ecosystems and the species within support the human race (Krebs, 2008, p 531).
There are a series of themes within ecosystem services, but the most obvious to people would be food. Food comes from soils full of millions of microscopic and not so microscopic creatures that help feed the plants by breaking down mineral particles in the soil. Trees make fruit, spices, and timber, protect us from strong winds and floods and make shade. Animals of many kinds have provided us with protein, from meat or milk for thousands of years, and their byproducts provide shelter from skins and tools from their bones or antlers. Even the oil we use to make plastic was once algae. Vast mangroves around coastal wetland areas used to prevent the flooding that cities are subject to these days, as they would slow the water. Forest cover on hills and mountains catches snow and rain and slows it as it melts or falls, allowing water to infiltrate into the ground, rather than rush across the top and cause erosion. The simple beauty of a forest is a service of nature.
The Millennium Ecosystem Assessment (2001-2005) defined four categories of ecosystem services:
Provisioning services – such as timber production, food production, wetlands filtering water
Regulating services – such as climate control, disease control, flood control
Supporting services – such as crop pollination, nutrient cycling
Cultural services – such as recreation, contemplation, ceremonial sites.
Natural capital is the land, water, atmosphere and biodiversity that provide the ecosystem services upon which we rely for our everyday needs. Underpricing natural capital has allowed it to be used as though it has little worth; in fact, these are the very systems that have allowed humans to achieve all the great things we have done. Without healthy soil, clean air and water we cannot thrive. The jungles of the Amazon provide the planet with about 20% of the earth’s oxygen yet it is removed at an alarming rate to grow beef for burgers in the developed world.
An ecosystem can withstand a certain number of losses and damage and still recover to a point of equilibrium where there are enough species to provide pollination or pest control and ecosystem services continue to function. However, with constant land use change and loss of biodiversity a point of no return can happen. Degraded landscapes can be difficult to repair, especially as climate change then adds further drying or flooding events to deal with.
*Embodied energy – emergy
This term describes the energy that has been used by all the industrial processes to create an end product. This includes the energy inputs used to create the machinery for mining the metals and fuels, the materials for building the factories and producing the products plus the energy used to deliver the product to its place of use or sale.
As an example, consider buying a can of tomatoes versus using fresh tomatoes. Canned tomatoes involve growing the tomatoes (fertiliser and its production can be energy intensive and cause pollution, watering and reticulation equipment), harvesting (mining the metals to build all the machinery to harvest and the fuel infrastructure needed to get the tomatoes to the processing plant), the metal can (another factory and more mining), packaging (forestry), labelling (inks) and delivery to the supermarket. Then driving to the supermarket to buy a can or ten of tomatoes.
Or, using unprocessed tomatoes hopefully grown within your general area, at least within the continent you live on. They still needs fertiliser, water and some transport, but not nearly as much embodied energy is contained within your tomatoes. Even better if you have made compost from your food wastes, have a vegetable garden and can simply walk out the back door and pick some tomatoes.
Unfortunately the words sustainable and sustainability have become smeared in greenwashing and corporate environmental policies.
If we don’t leave enough resources for future generations and a functioning environmental system there will be no humans.
“socially responsible economic development while protecting the resource base and the environment for the benefit of future generations” Agenda[ article 8.7