Net zero CO2 balances human CO2 emissions with human removals over a stated period. Avoiding emissions differs from removing atmospheric CO2. Other-gas claims need stated metrics. Energy changes need infrastructure, policy and choices. Proposed sunlight reflection would not remove CO2 or solve ocean acidification. Safety: No chemicals, electricity work, gas handling or intervention. No engineering, investment or family-spending advice. Stop: Stop after the paper recommendation. No hydrogen production, capture experiments, aerosol release, purchases, energy switching or political contacting.

Materials: Paper; Pencil; Ruler 1. Copy this illustrative annual CO2 budget in tonnes: emissions 100; renewable electricity avoids 25; electric transport/heat avoids 20; renewable hydrogen avoids 10; facility carbon capture prevents 15; direct air capture with durable storage removes 5. Avoided amounts do not overlap; all savings and removals are net of lifecycle emissions. Calculate emissions remaining, then subtract removals. 2. Copy five cards: Renewables need grid balancing/storage. Electrification depends on electricity supply. Green hydrogen uses renewable electricity to split water industrially, with energy losses. Facility CCS captures and stores CO2 before release, usually avoiding emissions. DAC captures ambient CO2; durable storage and energy emissions matter. Label each avoiding emissions or removing CO2 as applicable. 3. Revise the fictional budget: avoid another 20 and remove another 5, with no overlap. Check whether emissions now equal removals. Label Arithmetic scenario, not a feasible town plan. 4. Compare proposed sunlight-reflection methods: stratospheric aerosol injection adds reflective particles high in air; marine cloud brightening aims to increase low ocean-cloud reflectivity. Record two concerns: uneven rainfall effects and cross-border governance/consent. Explain why neither balances CO2. 5. Write four recommendation sentences: one council infrastructure/policy action, one possible household action subject to cost/access, why deep emission cuts matter, and one objection or unresolved question. No family disclosure or behaviour change is required. Done: A checked initial and revised budget, five cards, a two-method risk comparison and four recommendation sentences are complete. Proof: Keep budgets and recommendation. Note calculation, reading or writing help. This is supplied-data reasoning, not an actual emissions audit. Stop: Stop after the paper recommendation. No hydrogen production, capture experiments, aerosol release, purchases, energy switching or political contacting.