Great Stories

The escalating rate of anthropogenic CO2 emissions during the last 200 years has maintained the disequilibrium between atmospheric carbon fluxes. Figure 6.2 shows how the rate of atmospheric CO2 accumulation (dM/dt) has increased since about 1840. Accompanying this mass accumulation has been a steady and exponential rise in the atmospheric […]

Weathering and erosion processes in different climatic zones on the continental land masses may produce characteristic inorganic products. When these are carried to the oceans (by wind, rivers or floating ice) and deposited on the ocean floor, they convey information about the climate of their origin or transportation route, at […]

Most simulations suggest that the warming north of 50N in the winter half of the year should be enhanced due to ice-albedo feedback mechanisms (Manabe & Stouffer, 1980; Ingram et al., 1989). Over the last 100 years, high northern latitudes have warmed slightly more than the global mean during winter, […]

Sources of atmospheric CO2 can today be divided into two groups: natural and anthropogenic. Natural sources include the respiration of animals (60Gt per annum) and the surface ocean (90Gt per annum) (Schimel et al., 1995). Anthropogenic sources include the combustion of fossil fuels (power stations and transport) and cement production […]

Electricity generation from fossil fuels is a major source of carbon emissions, accounting for over 30% of CO2 emissions in 1990. A reduction in emissions attributable to electricity generation will be achieved through the development of new and renewable energy sources, including the increased use of combined heat and power […]

Beginning about 1450 A.D. there was a marked return to colder conditions. This interval is often called the Little Ice Age, a term used to describe an epoch of renewed glacial advance. Although many regions of the world experience cooling during the period 1450 to 1890 A.D., its use has […]

A number of other climatic indices reveal changes during the twentieth century and are discussed in the following sub-sections. 6.7.3.1. Tropospheric and Stratospheric Temperatures Changes Tropospheric and stratospheric temperatures are central to the problem of greenhouse warming because GCMs predict that temperature changes with enhanced concentrations of greenhouse gases will […]

In the mid-19th century, Croll (1867a, 1867b) proposed an astronomical theory linking the Pleistocene (2 Ma to 10 Ka) ice ages with periodic changes in the Earth’s orbit around the Sun. Croll’s ideas were later refined and elaborated by Milankovitch (1941). The Milankovitch theory is the name given to the […]

Variations in the abundance of the atmospheric greenhouse gases have the potential for changing the global climate. Variations in another group of species, namely the atmospheric aerosols, can also affect climate. Aerosols are solid or liquid particles dispersed in the air (Kemp, 1994), and include dust, soot, sea salt crystals, […]

Sections 6.4. to 6.6. reviewed the anthropogenic increase in atmospheric concentrations of greenhouse gases, and the associated increase in greenhouse radiative forcing. Section 6.7 examined the observed climate changes, principally in surface temperature, that have taken place during the last 100 to 140 years. In this section, the evidence for […]