Global change is the significant interactions of biological, chemical, and physical processes that pertains to changes in the earth system and that are most susceptible to human perturbation.
Global change takes place in air, water, soil and living organisms through a set of linkages. These linkages begin with incoming solar radiation and the earth atmosphere. The climate produced by this interaction affects all living things. The climate is also affected by those living things, by the land mass and water bodies of the earth, and by geologic activity.
The following links exist between climate and vegetation.
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Atmosphere
: affects plant survival and growth through carbon dioxide and pollutants: plants affect atmosphere by storing carbon and producing oxygen.
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Temperature
: determines plant survival, growth and geographic distribution; affects productivity, governs evaporation and transpiration; it is affected by plant biomass and reflectance properties of foliage.
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Water
: rainfall influences plant survival and growth, affects the regional water balance through evaporation and transpiration.
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Soil
: Stores water and controls plant-water relations, stores carbon, nitrogen and other chemicals. Also, it cycles nutrients through plants, releases chemical through the action of decomposers, and is eroded by surface runoff from rainfall.
Research has pointed to massive human impacts on land, water and the atmosphere. As economic development accelerated in all countries, population increased in poorer countries, stable ecologies such as tropical forests and the ocean were significantly degraded.
As larger economies and populations burned more fossil fuels and used more chemicals, this led to greater accumulations in the atmosphere of greenhouse gases - carbon dioxide (CO2), nitrogen, sulfur and chloro-floro carbons. These higher build up of gases have led to changes in the global environment. Scientists have mathematical models to show warming trends 50 to 100 times greater than changes since the last glaciation.
There are the four observable global-scale changes that are evident; accumulating greenhouse gases, diminished ozone layer; rising sea levels, and acid deposition. The greenhouse effect is produced when some of the infrared radiation is absorbed by carbon dioxide and re-radiated back to earth rather than being transmitted into space.
