Leadership

Although climate models should aid understanding in the processes which control and perturb the climate, the confidence placed in such models should always be questioned. Critically, it should be remembered that all climate models represent a simplification of the climate system, a system which indeed may ultimately prove to be […]

Atmospheric aerosol particles may be emitted as particles (primary sources) or formed in the atmosphere from gaseous precursors (secondary sources). Table 6.6 summarises the estimated recent annual emissions into the troposphere or stratosphere from the major sources of atmospheric aerosol, both natural and anthropogenic, primary and secondary. These include sulphates […]

There are many species of halocarbons, and it would be time consuming to detail the increases in atmospheric concentration of these species. Concentrations of halocarbons are typically measured in pptv. Those with solely anthropogenic sources have increased from zero concentration since they were first manufactured in the 1930s. There is […]

Although there are a number of ways of measuring and contrasting the radiative forcing potential of different greenhouse gases, the Global Warming Potential (GWP) is perhaps the most useful, particularly as a policy instrument. GWPs take account of the various factors influencing the radiative forcing potential of greenhouse gases. Such […]

The fact that the cause (the enhanced greenhouse effect) and effect (global warming) have not unambiguously been linked leads to the question: when is this [attribution] likely to occur? Detection is not a simple yes/no issue. Rather, it involves the gradual accumulation of observational evidence in support of model predictions. […]

Explosive eruptions can inject large quantities of dust and gaseous material (such as sulphur dioxide) into the upper atmosphere (the stratosphere – see Figure 1.1, section 1.2.2), where sulphur dioxide is rapidly converted into sulphuric acid aerosols. Whereas volcanic pollution of the lower atmosphere is removed within days by the […]

The overall state of the of the global climate is determined by the balance of solar and terrestrial radiation budgets (see Figure 1.3). How this energy balance is regulated depends upon the fluxes of energy, moisture, mass and momentum within global climate system, made up of its 5 components, the […]

The state of the global climate is one of general stability, engendered by a balance existing between the coupled components of the global climate system. The amount of incoming solar radiation is balanced by the amount of outgoing terrestrial radiation (section 1.2.3), so that the Earth neither continues indefinitely to […]

Atmospheric aerosol particles are conventionally defined as those particles suspended in air having diameters in the region of 0.001 to 10 m. They are formed by the reaction of gases in the atmosphere, or by the dispersal of material at the surface. Although making up only 1 part in 109 […]

Pollen grains and spores form the basis of another important aspect of palaeoclimate reconstruction, generally referred to as pollen analysis, or palynology. Where pollen and spores have accumulated over time, a record of the past vegetation of an area may be preserved. Often, changes in the vegetation of an area […]