The Earth's climate system has demonstrably changed on both global and regional scales since the pre-industrial era. Some of these changes are the result of human activities, such as the combustion of fossil fuels, agriculture and land-use changes.
These activities contribute to climate change by increasing the concentration of greenhouse gases, especially carbon dioxide (CO2), methane and nitrous oxide (NOx) in the atmosphere and trapping heat. The concentration of CO2 emissions in the atmosphere is estimated to be 30 per cent higher today than it was in pre-industrial times. The concentration of methane and other gasses has also increased.
Average surface temperature has risen by about 0.6C over the past 100 years and the consensus among international scientists recognised as specialists in the field is that it will rise by a further 1.4C to 5.8C between 1990 and 2100. Further increases in global warming risks a number of adverse effects, including the dramatic raising of sea levels and adverse changes to weather patterns. More information on climate change is available from the Intergovernmental Panel on Climate Change (IPCC), the United Nations Framework Convention on Climate Change, and the Australian Government report Climate Change – Risk and Vulnerability.
The minerals industry contributes directly to greenhouse gas emissions through the use of fuel such as petrol or diesel in vehicle fleets and equipment; the use of explosives in blasting; the release of methane from coal seams during mining activities; and the clearing of trees and vegetation for mine development. The industry in NSW and globally has taken this situation seriously for many years and was among the first to report its emissions and to set specific improvement targets.
Other initiatives include energy auditing and improvements in energy efficiency; reduction of haulage distances through improved mine planning and equipment relocation; using solar energy for remote equipment, such as lighting, pumps and environmental monitoring; upgrading compressed air and pumping systems, burners and burner controls; ensuring efficiency in materials handling of ores and concentrates; the capture and utilisation (including electricity generation) of waste coal seam methane; and the mass planting of trees and other vegetation as an aspect of rehabilitation and mine closure.
The minerals industry contributes indirectly to the production of CO2 emissions by mining the coal used by power stations. The NSW minerals industry strongly supports the development of technologies such as carbon capture and storage to minimise CO2, recognising that energy strategies for NSW should include a range of energy sources in addition to clean coal. Minerals companies are also active participants in Australian Government programs such as the Greenhouse Challenge Program involving voluntary initiatives by companies to reduce greenhouse gas emissions; and the Greenhouse Gas Abatement Program (GGAP) for projects involving very significant greenhouse gas abatement.
Case Study: BHP Illawarra Coal Appin Tower Power Project