Week 9: Global Cycles and their Alteration Flashcards
Biogeochemistry
The science that addresses the “biotic controls on chemistry of the environment and the geochemical control of the structure and function
of ecosystems”
Source-sink
A very low quality habitat that, on its own, would not be able to support a population.
Radiative forcing
A measure of how the energy balance of the Earth–atmosphere system is influenced.
Resistance time
How much an ecosystem resists change when faced with disturbances or stressors
Methanogenensis
The production of methane by
bacteria in the absence of oxygen.
Demographic transition
A switch from high birth and death rates to low birth and death rates.
Emerging infectious disease
Diseases appearing in the human population for the first time or expanding rapidly in incidence or geographic range (much faster than the rate of environmental change).
Zoonoses
Infections that circulate naturally in nonhuman vertebrate hosts but can be transmitted from these to humans.
Phosphorus cycle
The biogeochemical cycle that involves the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.
Carbon cycle
Describes how carbon moves between the atmosphere, soils, living creatures, the ocean, and human sources.
Paleoclimate data
Ice and Sediment cores can provide records of temperature, precipitation, CO2, and wind patterns.
Prediction & Uncertainty
In such a complex system, our knowledge of many parts of the climate system is unlikely to ever be definitive. However, it’s clearly the case that even uncertain answers can help us to work out the scale of the risks we face from climate change, and how to manage them
Nitrogen cycle
A biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil to organism and back into the atmosphere
Methane cycle
Begins in the soil where methane gas is created by microbes. Soil methane is consumed by methanotrophs, microorganisms that feed on methane. Methanogens make more methane that methanotrophs consume.
Methane & Permafrost
If the permafrost thaws too much, greenhouse gas emissions could escape and drive temperatures even higher. Beneath Svalbard’s permafrost, millions of cubic meters of methane are trapped — and scientists have now learned that it can migrate beneath the cold seal of the permafrost and escape.
