Tropical Forest Protection, Uncertainty, and the Environmental Integrity of Carbon Mitigation Policies

Tropical forests are estimated to release approximately 1.7 PgC per year as a result of deforestation. Avoiding tropical deforestation could potentially play a significant role in carbon mitigation over the next 50 years if not longer. Many policymakers and negotiators are skeptical of our ability to reduce deforestation effectively. They fear that if credits for avoided deforestation are allowed to replace fossil fuel emission reductions for compliance with Kyoto, the environment will suffer because the credits will not reflect truly additional carbon storage. This paper considers the nature of the uncertainties involved in estimating carbon stocks and predicting deforestation. We build an empirically based stochastic model that combines data from field ecology, geographical information system (GIS) data from satellite imagery, economic analysis and ecological process modeling to simulate the effects of these uncertainties on the environmental integrity of credits for avoided deforestation. We find that land use change, and hence additionality of carbon, is extremely hard to predict accurately and errors in the numbers of credits given for avoiding deforestation are likely to be very large. We also find that errors in estimation of carbon storage could be large and could have significant impacts. We find that in Costa Rica, nearly 42% of all the loss of environmental integrity that would arise from poor carbon estimates arises in one life zone, tropical wet. This suggests that research effort might be focused in this life zone.climate, economics, carbon sequestration, uncertainty, policy, tropics

Carbon Dynamics and Land-Use Choices: Building a Regional-Scale Multidisciplinary Model

Policy enabling tropical forests to approach their potential contribution to global-climate-change mitigation requires forecasts of land use and carbon storage on a large scale over long periods. In this paper, we present an integrated modeling methodology that addresses these needs. We model the dynamics of the human land-use system and of C pools contained in each ecosystem, as well as their interactions. The model is national scale, and is currently applied in a preliminary way to Costa Rica using data spanning a period of over fifty years. It combines an ecological process model, parameterized using field and other data, with an economic model, estimated using historical data to ensure a close link to actual behavior. These two models are linked so that ecological conditions affect land-use choices and vice versa. The integrated model predicts land use and its consequences for C storage for policy scenarios. These predictions can be used to create baselines, reward sequestration, and estimate the value in both environmental and economic terms of including C sequestration in tropical forests as part of the efforts to mitigate global climate change. The model can also be used to assess the benefits from costly activities to increase accuracy and thus reduce errors and their societal costs.carbon, sequestration, climate change, land use, modelling

Production of η′\eta\prime Mesons in the pp→ppη′pp \to pp\eta\prime Reaction at 3.67 GeV/c

The ratio of the total exclusive production cross sections for $\eta\prime$ and $\eta$ mesons has been measured in the $pp$ reaction at $p_{beam}=3.67$ GeV/c. The observed $\eta\prime/\eta$ ratio is $(0.83\pm{0.11}^{+0.23}_{-0.18})\times 10^{-2}$ from which the exclusive $\eta\prime$ meson production cross section is determined to be $(1.12\pm{0.15}^{+0.42}_{-0.31})\mu b$. Differential cross section distributions have been measured. Their shape is consistent with isotropic $\eta\prime$ meson production.Comment: 14 pages, 5 figures, accepted by Phys.Lett.

Ultrafast electronic read-out of diamond NV centers coupled to graphene

Nonradiative transfer processes are often regarded as loss channels for an optical emitter1, since they are inherently difficult to be experimentally accessed. Recently, it has been shown that emitters, such as fluorophores and nitrogen vacancy centers in diamond, can exhibit a strong nonradiative energy transfer to graphene. So far, the energy of the transferred electronic excitations has been considered to be lost within the electron bath of the graphene. Here, we demonstrate that the trans-ferred excitations can be read-out by detecting corresponding currents with picosecond time resolution. We electrically detect the spin of nitrogen vacancy centers in diamond electronically and con-trol the nonradiative transfer to graphene by electron spin resonance. Our results open the avenue for incorporating nitrogen vacancy centers as spin qubits into ultrafast electronic circuits and for harvesting non-radiative transfer processes electronically