The economic costs of planting, preserving, and managing the world's forests to mitigate climate change.

Forests are critical for stabilizing our climate, but costs of mitigation over space, time, and stakeholder group remain uncertain. Using the Global Timber Model, we project mitigation potential and costs for four abatement activities across 16 regions for carbon price scenarios of $5-$100/tCO2. We project 0.6-6.0 GtCO2 yr-1 in global mitigation by 2055 at costs of 2-393 billion USD yr-1, with avoided tropical deforestation comprising 30-54% of total mitigation. Higher prices incentivize larger mitigation proportions via rotation and forest management activities in temperate and boreal biomes. Forest area increases 415-875 Mha relative to the baseline by 2055 at prices $35-$100/tCO2, with intensive plantations comprising <7% of this increase. Mitigation costs borne by private land managers comprise less than one-quarter of total costs. For forests to contribute ~10% of mitigation needed to limit global warming to 1.5 °C, carbon prices will need to reach $281/tCO2 in 2055.

Optimal duration of risperidone or olanzapine adjunctive therapy to mood stabilizer following remission of a manic episode: A CANMAT randomized double-blind trial.

Atypical antipsychotic adjunctive therapy to lithium or valproate is effective in treating acute mania. Although continuation of atypical antipsychotic adjunctive therapy after mania remission reduces relapse of mood episodes, the optimal duration is unknown. As many atypical antipsychotics cause weight gain and metabolic syndrome, they should not be continued unless the benefits outweigh the risks. This 52-week double-blind placebo-controlled trial recruited patients with bipolar I disorder (n=159) who recently remitted from a manic episode during treatment with risperidone or olanzapine adjunctive therapy to lithium or valproate. Patients were randomized to one of three conditions: discontinuation of risperidone or olanzapine and substitution with placebo at (i) entry ('0-weeks' group) or (ii) at 24 weeks after entry ('24-weeks' group) or (iii) continuation of risperidone or olanzapine for the full duration of the study ('52-weeks' group). The primary outcome measure was time to relapse of any mood episode. Compared with the 0-weeks group, the time to any mood episode was significantly longer in the 24-weeks group (hazard ratio (HR) 0.53; 95% confidence interval (CI): 0.33, 0.86) and nearly so in the 52-weeks group (HR: 0.63; 95% CI: 0.39, 1.02). The relapse rate was similar in the 52-weeks group compared with the 24-weeks group (HR: 1.18; 95% CI: 0.71, 1.99); however, sub-group analysis showed discordant results between the two antipsychotics (HR: 0.48, 95% CI: 0.17; 1.32 olanzapine patients; HR: 1.85, 95% CI: 1.00, 3.41 risperidone patients). Average weight gain was 3.2 kg in the 52-weeks group compared with a weight loss of 0.2 kg in the 0-weeks and 0.1 kg in the 24-weeks groups. These findings suggest that risperidone or olanzapine adjunctive therapy for 24 weeks is beneficial but continuation of risperidone beyond this period does not reduce the risk of relapse. Whether continuation of olanzapine beyond this period reduces relapse risk remains unclear but the potential benefit needs to be weighed against an increased risk of weight gain.

Cost-Benefit Analysis of Managing the Papuana uninodis (Coleoptera: Scarabaeidae) Taro Beetle in Fiji.

Taro (Colocasia esculenta (L.) Schott) plays a prominent role in the economies and cultures of Pacific Island countries such as Fiji. Unfortunately, taro is highly susceptible to invasion from taro beetles, which burrow into the corms and weaken the plants, rendering them unmarkable and prone to rot. Papuana uninodis Prell, an invasive alien species that is native to the Solomon Islands and Vanuatu, was first reported on Viti Levu (Fiji's largest island) in 1984. Since that time, taro production on Viti Levu has fallen substantially. In this paper, we employ data from surveys of households and communities to document the impacts of P. uninodis on Viti Levu. We then identify three management approaches-chemical controls, cultural controls, and switching from taro to another staple crop-and conduct a cost-benefit analysis of each. We find strong arguments for pursuing chemical control, which derives a net present value of monetised benefits of about FJ$139,500 per hectare over 50 yr, or >FJ$21 for each FJ$1 spent. Still, any of the three management options is more efficient than no management, even without any attempt to quantify the benefits to biodiversity or forest protection, underscoring the value of actively managing this invasive alien species.