Global Issues

Energy balance models (EBMs) simulate the two most fundamental processes governing the state of the climate: a) the global radiation balance (i.e. between incoming solar and outgoing terrestrial radiation) (see section 1.2.4), and; b) the latitudinal (equator-to-pole) energy transfer (see section 1.2.5). EBMs are usually 0-D or 1-D in form. […]

Increasing greenhouse gases are expected to cause a rise in the global-mean sea level, due partly to oceanic thermal expansion and partly to the melting of land-based ice masses. However, as for global precipitation, such a variable is not wholly independent of global temperature. Thus, whilst both thermal expansion and […]

Epeirogeny is the term used to describe changes in the global disposition of land masses, and like orogenic processes, these changes are driven by internal plate tectonic movements. Because the internal dynamics of the Earth are slow, continents move about the globe at a rate of several centimetres per year. […]

As for the climate system, the rate at which the carbon cycle, and more specifically the atmospheric reservoir of CO2, adjusts to a new equilibrium in response to a forcing perturbation depends upon both the time scale of the forcing and the response period of the relevant components within the […]

The amount of water vapour in the air can be described in at least 5 ways, in terms of: 1) the water-vapour pressure; 2) the relative humidity; 3) the absolute humidity 4) the mixing ratio 5) the dewpoint. A full account of these definitions may be found in Linacre (1992). […]

Although solar variability has been considered, a priori, to be another external forcing factor, it remains a controversial mechanism of climate change, across all time scales. Despite many attempts to show statistical associations between various solar periodicities and global climate cycles, no realistic causal mechanism has been proposed to link […]

Once climate data has been collected and corrected for inhomogeneities, it will need to be analysed. The aim of any statistical analysis is to identify systematic behaviour in a data set and hence improve understanding of the processes at work to compliment the theory. Statistical analysis is a search for […]

The Earth, however, does have an atmosphere (section 1.2.1) and this affects its energy balance. The average global temperature is, in fact, 288K or 15C, 33K warmer than the effective radiation temperature. Although the Earth and Sun behave approximately as black bodies, this is not the case for the gases […]

Most of the gaseous constituents are well mixed throughout the atmosphere. However, the atmosphere itself is not physically uniform but has significant variations in temperature and pressure with altitude. Figure 1.1 shows the structure of the atmosphere, in which a series of layers is defined by reversals of temperature. The […]