Ecosystem refers to an interdependent group of natural elements and organisms that exist in a particular environment and the habitat with which these elements interact. Ecosystems are important because they sustain the natural world, providing humans with the resources we require in order to live and thrive.
An ecosystem (also known as a "biome") is a unit of the biosphere that has the functional components necessary to sustain itself, though there is sometimes significant interchange between ecosystems that exist next to each other. When adjacent ecosystems interact, they share material and energy. If one ecosystem collapses, it could take the surrounding ecosystems with it. This is especially the case when man-made ecosystems are involved (such as urban ecosystems, croplands and farms), in which case the natural balance has been altered by humans.
Millions of ecosystems make up our world. In a general sense, however, the word "ecosystem" is used to describe the world’s major habitat types. There are two major types of ecosystems: terrestrial (land-based) and aquatic (water-based.) Terrestrial ecosystems include forest biomes, arctic biomes, grassland biomes, desert biomes, tundra biomes, urban biomes and littoral (seaside) biomes, among thousands of others. Aquatic ecosystems include lake biomes, river biomes, swamp biomes as well as the massive range of systems within the ocean. Humans have hardly explored some of these ocean biomes, such as the deep-trench systems along the bottom of the sea.
Each distinct ecosystem consists of two major components: abiotic components and biotic components. Abiotic components include inorganic substances (chemical substances such as oxygen, carbon, nitrogen and compounds such as carbon dioxide and water), organic substances (potentially nutritional chemical compounds such as proteins, humus, fats) and climatic factors (such as the climate and soil). Biotic components are the organisms that live in the ecosystem and interact with one another to sustain the biome. There are three types of biotic components: producers (capable of making their own organic sustenance, such as trees), consumers (unable to make their own food and dependent on the other biotic components for feeding) and decomposers (those organisms that live on the dead animals and plants in the ecosystem.)
Since the term simply defines a system that has the abiotic and biotic elements to interact in a self-sustaining manner, there is no set size that defines an ecosystem. A valid biome can be as small as a corner of an empty lot or as big as the entire ocean. The size of an ecosystem simply depends upon the scale that the observer is studying, and whether the researcher can argue that the components of the subject ecosystem interact in a self-supporting community.
Global climate change is an imminent threat to the function of our world's ecosystems. Climate is a vital abiotic component of each ecosystem, and each organism in the system has developed over the course of millinea to thrive. Rapid changes to ecosystems leave organisms unable to adapt quickly enough to keep up. Climate change disrupts the relationship of the ecosystem's members to each other and to the habitats they occupy. Though, in some cases, climate change benefits a species by increasing its range, this often has detrimental effects on the surrounding systems. According to the Intergovernmental Panel on Climate Change, the ability of many ecosystems to naturally adapt to changing conditions will be wholly exceeded by the environmental disturbances we can expect from the rapid change of climate. Disturbances include floods, long-term drought, widespread fires, insect overbreeding and changes in the chemical balance of the ocean.