Climate Change · Paper 1 — Free Biology SL Practice Questions

Two graphs are presented to a student. The first shows global average temperature anomaly rising sharply after 1970; the second shows atmospheric CO₂ concentration rising sharply after 1950. The student concludes that rising CO₂ causes global warming because the two variables are positively correlated. Which statement is the most scientifically appropriate evaluation of this conclusion?

A climate summit is evaluating four mitigation strategies. Strategy X captures CO₂ from power plant exhaust and stores it in deep geological formations before it enters the atmosphere. Strategy Y involves planting fast-growing eucalyptus trees across large areas of degraded land. Strategy Z coats the ocean surface with reflective particles to reduce solar energy absorption. Strategy W replaces coal-fired power plants with nuclear reactors. Which strategy directly removes CO₂ already present in the atmosphere?