“Biodiversity is declining rapidly due to human activities; on this, there is a strong scientific consensus. However, the costs of delaying action to arrest and reverse biodiversity loss have not been examined until now.
Urgent action is needed to stem terrestrial biodiversity loss before it becomes much more costly and much less feasible to address. A delay of ten years from today will likely double the cost and make it infeasible to stabilize biodiversity intactness at even today’s degraded levels.
The analysis estimates relative cost, biodiversity intactness and species extinctions between ‘immediate’ and ‘delayed-action’ scenarios, each of which reaches a similar biodiversity outcome by 2050. In the immediate- action scenario, the global community acts now to stabilise biodiversity intactness at current levels by 2050. Decisive action begins in 2020 and prevents over 20% of the extinctions of endemic species that might have happened in a baseline scenario of currently implemented policies on climate change, biodiversity and area protection. In the delayed-action scenario, stronger actions to conserve biodiversity commence in 2030, with more abrupt and disruptive action thereafter to restore biodiversity intactness to current levels by 2050 (see Figure 1 a).1 In addition, a third scenario, ‘immediate high-ambition’, delivers an increase in biodiversity intactness from today’s levels by 2050.
The scope of this work is constrained to restoration through reforestation of naturally forested areas to generate positive outcomes for biodiversity as a result of global action. Actions targeting aquatic, coastal, marine and other terrestrial biodiversity lie beyond the scope of this work. However, biodiversity outcomes are estimated for all terrestrial biodiversity, and so the results serve as an indication of the scale of potential costs of inaction in other ecosystems.
● It is twice as expensive to delay action to stabilise biodiversity intactness globally as it is to act immediately.
● It is feasible to significantly reduce extinction rates of endemic species if action is immediate. Without greater action than currently implemented policies, more endemic species will go extinct in the coming 30 years than appear to have died out in the entire period 850-1850 CE.
● If action is immediate, there is an option to make a bigger reduction in extinction rates. This option would require immediate high-ambition action and is lost when action is delayed.
● If action is delayed, it becomes infeasible to stabilise biodiversity intactness globally even at today’s depleted level.
● The global cost of food and materials production from 2021 to 2050 is lower under immediate action and higher if action is delayed, as a share of global-average household income.
● Improve immediately the effectiveness of protected area enforcement, which is the cheapest form of action.
● Taking the example of forests, develop immediately reforestation programmes using planting, which will support biodiversity more quickly than natural regrowth, prioritising reforestation in areas of high species endemism in fragmented forest and adjacent to existing forest. Planting achieves outcomes fastest and targeting locations brings the greatest biodiversity benefit.
● Design biodiversity incentive mechanisms which complement greenhouse gas payments, to target biodiversity-rich areas and places with high restoration potential. Incentives will drive market action.
● Introduce rules requiring that reforestation and afforestation projects in receipt of funds from greenhouse gas payments (for example, carbon credits) also maximise biodiversity. Costs will be higher if carbon projects do not jointly deliver biodiversity.
● Announce immediately the future ambition and likely level of biodiversity incentives, and translate these into investor-relevant scenarios, so that people can take investment decisions consistent with them. Advance announcement keeps the costs of adjustment down.
● Redeploy immediately food and materials production subsidies into (i) yield improving technology adoption including ecological intensification and irrigation (where water is available), in locations where yields lag behind their potential; (ii) biodiversity incentives; and, (iii) funding of protected areas. Economic incentives must work for, not against, biodiversity, climate and nutrition outcomes…”