Managing extreme environments practice questions.

The Trans-Alaska Pipeline runs on elevated supports with heat pipes in the legs for about half its length. What problem does this design solve?

• Warm oil would thaw the permafrost and cause the supports to subside
• Elevation protects the pipeline from wind-blown sand abrasion
• Raised sections reduce the pumping energy needed to move the oil
• Supports above ground make the pipeline invisible to satellite monitoring

Answer: Warm oil would thaw the permafrost and cause the supports to subside

Oil leaves the field hot, and a buried hot pipe would melt ice-rich ground, which then loses volume and strength. Elevating the line and using thermosiphons that shed heat in winter keeps the ground frozen, and the raised sections also let caribou pass beneath.

Copper mining at Chuquicamata in Chile's Atacama depends on water in one of the driest places on Earth. Which response has the industry increasingly adopted?

• Desalinating seawater and pumping it inland to the mine
• Diverting rainfall from the mine site into storage reservoirs
• Relocating processing plants to the coast to avoid using water
• Abandoning flotation in favour of processes that need no liquid

Answer: Desalinating seawater and pumping it inland to the mine

Continental water in the Atacama is already allocated and its abstraction has damaged wetlands and indigenous communities, so mines have turned to desalination plus long high-lift pipelines. It removes the competition for freshwater at a large energy cost, which is the characteristic trade-off of extraction in extreme environments.

Tourism in Antarctica is regulated largely through the operators' own association, which sets limits such as a maximum number of visitors ashore at one site at a time. Why does this indirect approach dominate?

• No single state has sovereignty, so there is no national regulator to enforce rules
• Tourist numbers are too small for any regulation to be necessary
• The Antarctic Treaty explicitly forbids all regulation of visitors
• Ships in Antarctic waters are outside the jurisdiction of their flag states

Answer: No single state has sovereignty, so there is no national regulator to enforce rules

The Antarctic Treaty suspends territorial claims, so the usual route - a state licensing activity on its own land - does not exist. Self-regulation fills the gap and works while operators value their reputation, but it binds only members and has no penalty comparable to law.

In Almería, southern Spain, tens of thousands of hectares of greenhouses produce vegetables for northern European markets in a semi-arid climate. What is the principal environmental cost?

• Aquifer over-abstraction and saline intrusion near the coast
• A large increase in local rainfall caused by the plastic covers
• Loss of the region's tropical rainforest to greenhouse construction
• Complete elimination of the need for fertiliser and pesticide

Answer: Aquifer over-abstraction and saline intrusion near the coast

Year-round irrigated production in a dry region draws groundwater faster than it recharges, and near the coast seawater moves in to replace it, ruining wells. The plastic sea has also raised local albedo, which cools rather than warms the surface, but the water balance is the binding constraint.

Libya's Great Man-Made River pipes groundwater from the Nubian Sandstone Aquifer System beneath the eastern Sahara to cities on the Mediterranean coast. The aquifer receives almost no recharge under today's climate. Which planning implication follows most directly?

• Abstraction can continue indefinitely provided the pumps are efficient.
• The scheme has a finite life, so a replacement supply must be planned.
• Reducing coastal demand would let the aquifer refill within a few decades.
• Harvesting the desert's rainfall could restore the level of the aquifer.

Answer: The scheme has a finite life, so a replacement supply must be planned.

Fossil water accumulated under a wetter past climate, so abstraction is mining a stock rather than living off a flow; efficiency changes only how long the stock lasts. Present desert rainfall is far too small to recharge it on any human timescale.

Herders on the Mongolian steppe lose large numbers of animals in dzud winters. Under index-based livestock insurance, a payment is triggered when recorded livestock mortality for a whole district passes a set percentage, rather than when an individual herder's animals die. What is the main advantage of that design?

• Payments can be made quickly, without checking each herder's losses.
• It guarantees that every herder is fully compensated for the animals lost.
• It removes the need for herders to move animals between seasonal pastures.
• It prevents dzud winters from reducing the size of the national herd.

Answer: Payments can be made quickly, without checking each herder's losses.

Verifying claims across thousands of dispersed camps would cost more than the payouts, so an index keeps the scheme workable; the trade-off is basis risk, since a herder who loses everything in a district with average mortality receives nothing. Insurance transfers losses, it does not prevent them.