Although human activity across Antarctica has increased during recent decades, it remains much lower than for all other continents. Human activity in Antarctica is highly seasonal, with the peak presence and activity occurring during the summer months. Although Australia and other nations maintain a year-round presence in Antarctica, there are no truly permanent human populations.

Human activity in Antarctica is concentrated in ice-free areas, which account for approximately 0.18 per cent of the continent. Most Antarctic stations are adjacent to the coast to facilitate access by ship for resupply of stations with essential provisions, such as food and fuel. The environmental impacts of human activities in these areas must be carefully managed, because these ice-free areas also support the greatest biodiversity of terrestrial plants and animals. Human impacts include disturbance and modification of the landscape, and contamination of the air, land and coastal marine environments with a variety of pollutants.

The Protocol on Environmental Protection to the Antarctic Treaty was adopted in 1991 and signed into force in 1998. Its aim is to provide comprehensive and legally binding protection of the Antarctic environment. All human activities are to be assessed for their potential impact on the environment and associated ecosystems. Although the protocol prohibits the introduction of any species not native to Antarctica, there are limited exceptions, including the controlled use of hydroponic systems for growing fresh produce that otherwise would be unavailable for lengthy periods because of transportation constraints.

Operation indicators

Under Article 17 of the Protocol on Environmental Protection to the Antarctic Treaty (Madrid Protocol), all parties are required to report annually on steps taken to implement the protocol. These include the adoption of laws and regulations, administrative actions and enforcement measures to ensure compliance with the protocol. The Madrid Protocol also requires that contingency plans are established to respond to incidents with potential adverse effects on the Antarctic environment, or on dependent and associated ecosystems.

Each year, various ships and aircraft transport people and goods to and from Australia’s 4 permanently occupied research stations of Casey, Davis, Mawson and Macquarie Island. During recent years, the winter populations at the Australian stations have remained relatively stable; they have typically been 16–22 people on the continent and 13–15 on Macquarie Island. An exception occurred on Macquarie Island in 2011 and 2012, when the winter population peaked at 38 during the Macquarie Island Pest Eradication Program, in which rodent and rabbits were eradicated from the island (see Box ANT1). For many years, Davis Station had the largest summer population, with up to 100 personnel. However, Casey Station now has a much larger number of expeditioners coming and going throughout the summer season because of the improved access to Antarctica by air transport. Prevailing weather conditions do not allow use of the runway during winter.

The effective number of people participating annually in the Australian Antarctic Program is shown in Figure ANT13. Participation since the mid-2000s has been lower than in the preceding decades, largely because of reduced construction activity at the 3 continental stations.

The AAD operates the icebreaking research and resupply vessel Aurora Australis from mid-October until April the following year. Winter travel to Antarctica is not possible because of the extensive sea ice that prevents access to the coastal areas where the stations are located.

The AAD undertakes voyages for a range of purposes, primarily the resupply of the stations, and deployment and retrieval of personnel, as well as marine science research. The Aurora Australis caters for all these purposes. Occasionally, other vessels may be chartered for a particular task, such as waste removal, Southern Ocean and marine science research activities, or transport of personnel to and from Macquarie Island. In October 2015, the Australian Government unveiled its plans for a new icebreaker that will offer scientists unprecedented and extended access to the Southern Ocean and Antarctica. The vessel is expected to be commissioned in late 2020.

The AAD also uses a range of aircraft to transport passengers and cargo (see Shipping and aircraft operations). During the 2015–16 summer, the AAD and the Royal Australian Air Force successfully flew several joint operational missions to East Antarctica with a C-17 Globemaster III, which delivered heavy-lift cargo to Wilkins Aerodrome in support of the Australian Antarctic Program. The use of this type of heavy-lift aircraft has the potential to significantly improve the AAD’s logistical and scientific capabilities.

The AAD uses a well-established set of operational indicators to monitor and assess human impact on the environment associated with the Australian Antarctic Program. Several of these are discussed below.

Waste treatment and disposal

Annex III of the Madrid Protocol outlines the obligations of national programs for waste disposal and management. Antarctic research stations generate a variety of wastes, including liquid waste (human waste, water from kitchens and bathrooms, and from operational activities in workshops) and solid waste (e.g. materials for landfill and recycling). Burning of fossil fuels for power generation, powering of vehicles and waste incineration at the stations contributes to emissions into the environment.

Wastewater effluent is discharged directly to the sea adjacent to the stations. At Davis and Macquarie Island, sewage is macerated and released. Maceration is the minimum level of sewage treatment required under the Madrid Protocol. At Macquarie Island, sewage is discharged into a high-energy environment where the macerated particles are quickly diluted and dispersed. The AAD has recently installed a new wastewater treatment facility at Davis. The plant was commissioned during the 2015–16 summer (Box ANT7). This new facility will greatly improve the environmental outcome for the area. During the project’s second stage, an advanced wastewater treatment plant will be installed, which will have the capacity to produce potable water.

At Casey and Mawson stations, treatment plants process the sewage before it is released into the ocean. Biological oxygen demand (BOD) measurements assess how effective waste treatment plants are in removing organic matter from the sewage and how much organic matter is being released into the ocean. Figure ANT14 provides an annual summary of BOD measurements for each of these stations since 2001, from measurements made at approximately monthly intervals. The values for 2011–15 are 24 milligrams per litre (mg/L) for Casey (from 49 measurements) and 11 mg/L for Mawson (from 53 measurements). By comparison, the marine emissions limit for accepted modern technology in Australia is 10 mg/L (DPIWE 2001). A value of 60 mg/L for an individual measurement indicates poor efficiency in the treatment plant, and this threshold is occasionally reached when occupation of the stations is highest. For 2011–15, the threshold was exceeded on 8 occasions at Casey and 4 occasions at Mawson.

The quantities of suspended solids are also measured at the 2 stations. Suspended solids indicate how efficiently the waste treatment plants break down organic matter, and the amount of organic matter that is released into the ocean because of human occupation. Figure ANT15 provides an annual summary of suspended solids measurements for the 2 stations since 2001, from measurements made at approximately monthly intervals. The values for 2011–15 are 3 mg/L for Casey (from 50 measurements) and 20 mg/L for Mawson (from 56 measurements). Similar to BOD measurements, a value of 60 mg/L for an individual measurement indicates poor efficiency in the treatment plant, and this threshold is occasionally reached when occupation of the stations is highest. For 2011–15, the threshold was exceeded on 3 occasions at Casey and 9 occasions at Mawson.

Waste is minimised wherever possible—for example, reducing packaging waste by delivering goods to Antarctica in minimal packing. Substances such as washing powders and dishwashing liquids are biodegradable.

As with any community in Australia, the Australian Antarctic and subantarctic research stations generate a volume of waste in proportion to the station population and level of activity. This waste has been generated since the stations were established. However, how the waste has been managed over time has changed as the organisation has moved into a more enlightened era in terms of environmental management and Antarctic stewardship.

When stations were first established, the practice of ‘return to Australia’ was not considered necessary, and waste was disposed of at localised tip sites near the stations. This was in keeping with the way waste was handled in Australia and elsewhere in Antarctica at that time. These practices ceased when the Madrid Protocol came into effect. However, the tip sites and related waste disposal practices, although abandoned, have left an ongoing environmental legacy (see Contaminated sites and pollution). Through the Australian Antarctic strategy and 20-year action plan (2016), the Australian Government has committed to developing a plan to remove legacy waste and continue the remediation of contaminated sites (Australian Government 2016).

Clean-up operations have already started. In 2011, the remaining legacy waste at the Thala Valley waste site at Casey was returned to Australia. The site is being monitored, and results will be validated in terms of environmental impacts. Tip sites at the Mawson, Davis and old Wilkes stations remain unresolved, and continue to present an environmental legacy and ongoing impact.

Waste generated annually and materials no longer required on station are returned to Australia for recycling, re-use or disposal. Waste typically includes general landfill and commingled recycling, such as paper, glass, aluminium and plastic (polyethylene terephthalate [PET] and high-density polyethylene [HDPE]), sewage sludge, paint, oil, steel, copper, brass, building materials and laboratory chemicals.

Some waste cannot be returned to Australia for quarantine reasons and is incinerated at the station. This includes kitchen scraps, medical waste and human waste returned to the station from field activities. Incineration results in a range of emissions to the environment, and Australia aims to minimise the amount of materials incinerated on the stations by diverting materials from incineration to re-use or recycling. The ash from incinerators is stored on station and returned to Australia for disposal. Data are collected on the amount of material incinerated, as well as all waste returned to Australia. New wastewater treatment facilities under construction have been designed to process food waste, and have the potential to greatly reduce the amount of material incinerated on station. The AAD regularly reviews the environmental impacts of waste activities, the extent of station community compliance with waste-management guidelines and the economics of recycling.

Waste is returned to Australia by ship, usually during the resupply of the stations. The amount of waste returned to Australia each year is highly variable and dependent on the availability of cargo space on the ship, shipping schedules, and sea ice and weather conditions during station resupply. Figure ANT16 shows the total mass of waste returned to Australia and incinerated at the stations from 1999–2000 to 2014–15.

Fuel use

The quantity of fuel used by generator sets, boilers, vehicles and incinerators at all stations is recorded and reported annually (Figure ANT17), as is the use of fuel for shipping and aviation (see Shipping and aircraft operations). The environmental impact of transport and use of fuel in Antarctica is associated with emissions released from power generation and heating. A special cold-climate light-diesel fuel, special Antarctic blend (SAB), is used at the stations to power generator sets, to provide heat through boilers, and to run plants and equipment, including the station incinerators and vehicles. Operations at the Wilkins Aerodrome near Casey, which is used for the airlink to Australia, are largely responsible for the increase in vehicle fuel use since the mid-2000s.

In addition to reflecting population numbers and climatic conditions, fuel consumption reflects the energy efficiency of electrical and heating systems. The AAD is continually exploring energy-efficient equipment and energy-saving strategies. Although the occupancy of the stations is less during winter than summer, the need for electricity increases because the design of most buildings means that they cannot be closed down during winter and require additional heating. A few small buildings have their own electrical heating systems. Fuel-efficient ‘cold pump’ technology is used for the long-term storage of perishable food.

Vehicle use differs between summer and winter. During winter, vehicle use tends to be less than in summer—populations at the stations decrease to about 15–20 people, and vehicles are generally not used in bad weather. Station populations peak in summer, and the demand for resources tends to increase; this includes the use of water and fuel.

Casey Station has the highest level of fuel consumption, mostly because of the operation of Wilkins Aerodrome. Transport of passengers and cargo between Wilkins and Casey Station involves a 140-kilometre round trip. Also, the preparation and maintenance of the ice runway during summer requires the use of heavy plant at the aerodrome and approximately 10,000 litres of SAB per week. The maintenance of buildings and facilities at the aerodrome used by personnel throughout summer has an ongoing demand for energy. During winter, fuel use at Casey is similar to that at the other continental stations. At Macquarie Island, vehicle use is much lower than at the Antarctic stations and is largely limited to the immediate station surrounds.

Electricity use is affected by the season and weather, and can fluctuate from year to year depending on temperatures and the number of people on station at any one time (Figure ANT18). At Mawson Station, wind turbines continue to make a significant renewable contribution to the station’s electrical and heating energy requirements. For the past decade, wind energy has provided around 40–45 per cent of the energy needs at Mawson. Furthermore, waste heat from the station’s diesel-powered electrical generators is captured and used to warm the station buildings, in combination with boilers powered by the wind turbines and boosted by diesel-fired boilers.

Shipping and aircraft operations

The quantity of fuel used by ships travelling to Australian Antarctic research stations and on marine science voyages differs because of variations in shipping demands among years. Marine gas oil is a marine version of normal diesel, and is used on the vessels to power the main engines and generator sets, to provide propulsion and general services—such as power and heating—to the vessels. IFO 40 (RMC 10) is a light-grade fuel oil used by some of the vessels engaged by the AAD. This fuel is used for the main engines and, in some cases, the generators.

The AAD’s Australian–Antarctic Airlink operates a seasonal intercontinental air service from Hobart to the Wilkins Aerodrome, which is 70 kilometres inland from Casey Station. The air transport link can move up to 400 passengers each summer season and a limited amount of high-priority, lightweight cargo (current maximum of 1500 kilograms per flight). The Airbus A319-115LR was selected for this flight, partly because it has sufficient range for a return trip from Hobart to Antarctica without refuelling in Antarctica. This avoids a range of potential environmental risks associated with the transport, handling and storage of large volumes of jet fuel.

The AAD has been using BT-67 Basler (DC-3) and DHC-6 Twin Otter aircraft for intracontinental operations since 2010. These ski-equipped aircraft transport people and cargo from Wilkins to ski-landing areas at Casey, Davis and Mawson stations, and other field locations.

The fixed-wing aircraft work closely with up to 4 AS-350 B3 ‘Squirrel’ helicopters to provide support to a range of projects and to provide helicopter services from the icebreaker Aurora Australis. When the sea ice runway no longer exists, helicopters are used to transport passengers between Davis Station and the ski-landing area on the plateau, 20 nautical miles away—a journey of about 20 minutes from the station.

In 2015, the AAD undertook an initial environmental evaluation of its aviation operations. This was the first wholesale environmental assessment of the range of aviation activities, and their actual, potential and cumulative impacts on the Antarctic environment. The result was the issuance of an environmental authorisation for 2015–20 under s. 12F of the Antarctic Treaty (Environment Protection) Act 1980 with several conditions attached, including the need to develop appropriate options to monitor the impacts of aviation activities.

Annual shipping and aviation fuel use data for the Australian Antarctic Program are shown in Figure ANT19.

Carbon dioxide emissions

Annual estimated CO₂ emissions for components of the Australian Antarctic Program are shown in Figure ANT20. Since 2010, there has been a general decline in emissions, largely because of a decrease in use of shipping fuel.