3.2.1.5.1 - Antarctic pressures and environmental change

Climate, ice and satellite evidence

Climate change affects Antarctic land ice, ocean conditions and sea ice through different processes and with different consequences.

Warmer ocean water can melt ice shelves from below. Shelves restrain, or buttress, some land-ice flows; their weakening can allow grounded ice to move more rapidly into the sea. Loss of grounded land ice adds water to the ocean and raises global sea level. Melting floating ice has little direct effect on sea level, but loss of its ecological habitat or buttressing role can still be important. Regional conditions and ice-sheet responses vary. BAS, Antarctica and climate change, 2017 briefing.

In the central and eastern Bellingshausen Sea, satellite evidence linked early sea-ice break-up in 2022 with breeding failure at four of five emperor-penguin colonies studied. Chicks depend on stable ice until they develop waterproof feathers; early break-up can lead to drowning or freezing. This is a particular region and breeding season, not evidence that every Antarctic colony failed. Fretwell and colleagues, 2023 primary research.

Remote sensing obtains information at a distance, for example from satellites. Repeated images can show sea-ice cover and colony traces over a large, inaccessible area. BAS describes identifying guano stains on the ice in Sentinel-2 imagery. Such traces are a proxy for colony presence; image timing, clouds, resolution and a move to another site affect interpretation. Repeated observations and other evidence strengthen an inference about breeding success. BAS study explanation, 24 August 2023.

Distinguish observation, such as early break-up, from attribution, which explains its causes. A single extreme season does not quantify the human contribution to it: winds, storms and ocean variability also influence ice. Climate trends and models provide a wider evidence base, while an individual image cannot establish a long-term trend. Nor does a projected future loss represent an observed present outcome.

Fishing, whaling and connected food webs

Removing marine animals can change both the target population and relationships within Antarctic ecosystems.

Krill connect phytoplankton with predators including penguins, seals and whales. Fishing can provide food, feed ingredients and commercial income, while locally concentrated catches may reduce prey available near breeding sites. A small share of an enormous regional biomass can still matter if taken in a predator's feeding area at a critical season. The relevant unit is therefore not only a whole-ocean total.

CCAMLR's 2024 Area 48 krill fishery report treats krill's central ecosystem role as fundamental to management and records concern about sporadic, localised fish by-catch events. By-catch is the unintended capture of non-target organisms. Fishing pressure includes these direct effects as well as competition for prey. Reported catches, observer records and surveys measure different aspects of the fishery; a permitted catch is not proof of zero ecological effect. CCAMLR, Fishery Report 2024, Area 48.

Historical intensive whaling depleted populations and changed marine relationships. Removing long-lived animals faster than reproduction replaces them creates a recovery problem; species and populations recover at different rates. CCAMLR describes concern about a repeated boom-and-bust pattern in krill harvesting following whaling as part of the context for its development. CCAMLR, krill biology and fishing.

The IWC commercial-whaling moratorium is distinct from fishing regulation. It limits commercial catches for the governments bound by it; it does not remove threats from entanglement, shipping, pollution or climate change. An IWC 2024 resolution explicitly recognises commercial whaling under objections/reservations and by non-contracting governments. It is therefore inaccurate to claim that the 1982 decision ended every whale hunt worldwide. IWC Resolution 2024-3.

Mineral interest and potential disturbance

Interest in Antarctic minerals is a potential economic pressure whose effects must be distinguished from current legal permission and demonstrated extraction.

Searching commercially for minerals can require surveys, drilling, fuel, transport and infrastructure. Disturbance, spills and waste may affect limited ice-free habitats, while severe conditions make clean-up difficult. Large-scale extraction would add further infrastructure and risks. The presence of geological interest does not establish a viable reserve: a resource is a geological occurrence, whereas an economically workable reserve depends on evidence, technology, cost and legal access.

The Environmental Protocol, signed in 1991 and effective from 1998, prohibits Antarctic mineral-resource activities except scientific research. Scientific geological work is not a licence for commercial exploration. Neither the Protocol nor the Treaty expires in 2048; from that year a review conference may be requested under specified conditions. A date permitting review is not automatic permission to mine. Antarctic Treaty Secretariat, Environmental Protocol explanation.

Protection reduces one avenue of economic pressure, while future demand and political interests can still prompt debate. Evaluate an asserted threat by checking whether it is observed activity, a proposal, a possible future pressure or an unsupported claim. No current commercial Antarctic mining operation is inferred here from geological potential.

Tourism, location and intensity

Tourism brings income and experiences while concentrating transport and visitor activity at accessible places and seasons.

IAATO's dated 2024 report records 78,848 vessel-tourism passengers making landings and 43,224 cruise-only passengers in 2023/24, compared with 71,362 and 32,730 in 2022/23. Its 2023/24 vessel total was 122,072; these categories exclude deep-field activity and non-member data. Cruise-only passengers did not make shore landings in that category, so the total cannot be called 'people landing'. IAATO, ATCM46 IP102 rev1, Table 2 and Appendix 1.

Landings can disturb animals, trample vegetation or transfer non-native organisms on clothing and equipment. Ships and aircraft also use fuel and produce waste; accidents create risks even without a landing. A cruise-only voyage therefore has a different footprint, rather than no footprint. Biosecurity comprises measures to prevent the introduction or spread of organisms, such as cleaning boots and equipment.

The report places 98% of tourism voyages in the Peninsula region during the austral summer. This is a voyage share, not 98% of the Antarctic land area or necessarily the same passenger share. Concentration increases the importance of site-specific limits and cumulative effects where many operators use the same sites. Ecological impact depends on duration, behaviour, wildlife proximity and the receiving environment, not a visitor total alone.

IAATO is an industry association: its operators supply activity records and it develops operational practices. Those records are useful primary activity evidence, but do not independently prove that the industry's environmental effects are acceptable. Compare activity data with ecological monitoring and explicit site conditions.

Research benefits and environmental footprints

Scientific research can support Antarctic protection while its own operations create local pressures.

Stations require buildings, transport, power and supplies. Fuel spills, waste, sewage and disturbance can affect soils or marine environments; field equipment and cargo can transport non-native organisms. A scientific purpose does not remove these pathways. The Australian Antarctic Program records contaminated sites left by earlier station waste practices and compares disturbed waste at Thala Valley near Old Casey with an undisturbed site near Wilkes. Australian Antarctic Program, contamination research.

This case shows a lasting local legacy and a further dilemma: removing waste may mobilise contaminants or damage the environment. The programme's remediation research examines techniques suited to cold conditions and the risks of clean-up itself. These are investigated pressures and responses, not proof that every station has identical contamination. Australian Antarctic Program, remediation and restoration.

Research also produces information needed to detect change, assess threats and design protection. Sharing facilities and transport, reducing waste and selecting less intrusive methods can lower impacts while retaining scientific benefits. Satellite observation can reduce some need for travel, but may still need ground validation. Compare methods against both the quality of knowledge produced and the footprint created.

Pressures interact. Warming may alter which organisms survive after introduction; tourism and research can share accessible sites; fishing can compound changes in prey distribution. These conditional pathways do not prove that all threats cause the same impact everywhere. A sound assessment combines exposure, sensitivity, scale, timing, cumulative effects and the evidence supporting each claim.