What timeframe is associated with halving deforestation when replacing 20% of beef with mycoprotein?

• A. Five years
• B. Ten years
• C. Twenty years
• D. Thirty years

Answer: (D)

The time horizon test here is about how fast the benefits of replacing beef with mycoprotein show up in deforestation trends. Beef uses a lot of land, both for pasture and for growing feed, so shifting some demand away from beef to a high‑protein, low-land alternative reduces pressure on forests. But changes in deforestation don’t happen overnight—the decisions that drive clearing, the way land can be conserved or allowed to recover, and how markets and policies respond all play out over many years. In this scenario, enough cumulative land-use savings accumulate only after a few decades to noticeably slow the deforestation rate, reaching about half of the previous rate after roughly thirty years. Shorter horizons don’t capture that gradual build-up, which is why the longer timeframe is the best fit.