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31.
Conservation outcomes are uncertain. Agencies making decisions about what threat mitigation actions to take to save which species frequently face the dilemma of whether to invest in actions with high probability of success and guaranteed benefits or to choose projects with a greater risk of failure that might provide higher benefits if they succeed. The answer to this dilemma lies in the decision maker's aversion to risk—their unwillingness to accept uncertain outcomes. Little guidance exists on how risk preferences affect conservation investment priorities. Using a prioritization approach based on cost effectiveness, we compared 2 approaches: a conservative probability threshold approach that excludes investment in projects with a risk of management failure greater than a fixed level, and a variance‐discounting heuristic used in economics that explicitly accounts for risk tolerance and the probabilities of management success and failure. We applied both approaches to prioritizing projects for 700 of New Zealand's threatened species across 8303 management actions. Both decision makers’ risk tolerance and our choice of approach to dealing with risk preferences drove the prioritization solution (i.e., the species selected for management). Use of a probability threshold minimized uncertainty, but more expensive projects were selected than with variance discounting, which maximized expected benefits by selecting the management of species with higher extinction risk and higher conservation value. Explicitly incorporating risk preferences within the decision making process reduced the number of species expected to be safe from extinction because lower risk tolerance resulted in more species being excluded from management, but the approach allowed decision makers to choose a level of acceptable risk that fit with their ability to accommodate failure. We argue for transparency in risk tolerance and recommend that decision makers accept risk in an adaptive management framework to maximize benefits and avoid potential extinctions due to inefficient allocation of limited resources. El Efecto de la Aversión de Riesgo sobre la Priorización de Proyectos de Conservación  相似文献   
32.
运用共同但有区别的责任原则、风险预防原则、污染者负担原则等国际环境法上的基本原则,针对美国拒绝批准《京都议定书》所持的三个抗辨理由,一一进行了法理分析与批判。  相似文献   
33.
Joint Implementation (JI) and theClean Development Mechanism (CDM) have beenestablished under the United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol asproject-based instruments to mitigategreenhouse gases of the industrialisedcountries to the levels imposed by theirKyoto commitments. An outstanding issueassociated with the implementation of thesetwo flexibility mechanisms concerns thechoice of appropriate baseline forcalculating the emission reductions. Thispaper applies a computerised tool thatconstructs and compares different types ofstandardised baselines for projects inIndonesia, Panama and the RussianFederation. It evaluates the effects of theselection of different baselines to theenvironmental integrity of the two Kyotomechanisms.  相似文献   
34.
Preliminary analysis based on an aggregate model of global carbon emissions suggests that constraining emissions to the levels that would be imposed by compliance with the results of the Kyoto negotiations can increase the discounted cost of ultimately limiting atmospheric concentrations. Kyoto targets can be either too restrictive or too permissive depending upon the (currently unknown) trajectory of carbon emissions over the near- to medium-term and the (as yet unspecified) concentration target that frames long-term policy. The discounted cost of meeting low concentration targets like 450 ppmv. is diminished by allowing large sinks and/or by imposing more restrictive near-term emissions benchmarks (even if only Annex B countries are bound by the Kyoto accord). Conversely, the cost of achieving high concentration targets like 650 ppmv. is diminished by disallowing sinks and/or by imposing less restrictive emissions benchmarks. Intermediate concentration targets like 550 ppmv. look like high concentration targets (favoring no sinks and expanded near-term emissions) along low emissions paths; but they look like low concentration targets (favoring the opposite) along high emissions paths. Emissions trajectories that lie above the median, but not excessively so, represent cases for which adjustments in the Kyoto emissions benchmarks and/or negotiated allowances for sinks have the smallest effect on the cost of mitigation.  相似文献   
35.
This paper proposes a computable stochastic equilibrium model to represent the possible competition between Russia and China on the international market of carbon emissions permits. The model includes a representation of the uncertainty concerning the date of entry of developing countries (e.g., China) on this market in the form of an event tree. Assuming that this date of entry is an uncontrolled event, we model the competition as a dynamic game played on an event tree and we look for a solution called S-adapted equilibrium. We compare the solution obtained from realistic data describing the demand curves for permits and the marginal abatement cost curves in different countries, under different market and information structures: (i) Russia's monopoly, (ii) Russia–China competition in a deterministic framework, (iii) Russia–China competition in a stochastic framework. The results show the possible impact of this competition on the pricing of emissions permits and on the effectiveness of Kyoto and post-Kyoto agreements, without a US participation.  相似文献   
36.
Many trace constituents other than carbon dioxide affect the radiative budget of the atmosphere. The existing international agreement to limit greenhouse gases, the Kyoto Protocol, includes carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and credit for some carbon sinks. We investigate technological options for reducing emissions of these gases and the economic implications of including other greenhouse gases and sinks in the climate change control policy. We conduct an integreated assessment of costs using the MIT Emissions Prediction and Policy Analysis (EPPA) model combined with estimates of abatement costs for non-CO2 greenhouse gases and sinks. We find that failure to take advantage of the other gas and sink flexibility would nearly double aggregate Annex B costs. Including all the GHGs and sinks is actually cheaper than if only CO2 had been included in the Protocol and their inclusion achieves greater overall abatement. There remains considerable uncertainty in these estimates, the magnitude of the savings depends heavily on reference projections of emissions, for example, but these uncertainties do not change the overall conclusion that non-CO2 GHGs are an important part of a climate control policy.  相似文献   
37.
Susan Solomon 《Ambio》2021,50(1):44
Crutzen (1974) and Crutzen and Ehhalt (1977) presented two key papers in Ambio that in Ambioexemplify how science first revealed to humankind the potential for damage to our ozone shield in the Anthropocene. Crutzen’s (1974) review is a sweeping summary of the risks to the ozone layer from supersonic aircraft, chlorofluorocarbons, as well as nuclear weapons testing and nuclear war. Crutzen and Ehhalt (1977) described how the nitrous oxide produced from fertilizers could pose another threat to the stability of the stratospheric ozone layer. The two papers are part of a body of influential scientific work that led to the pioneering Montreal Protocol to Protect the Earth’s Ozone Layer to phase out production of chlorofluorocarbons (in 1987), as well as national decisions that slowed or stopped production of supersonic planes (in the 1970s). They remain guideposts today for ongoing international negotiations regarding reducing emissions from fertilizer and limiting nuclear testing.  相似文献   
38.
Abstract:  Tradable permits are increasingly becoming part of environmental policy and conservation programs. The efficacy of tradable permit schemes in addressing the root cause of environmental decline—economic growth—will not be achieved unless the schemes cap economic activity based on ecological thresholds. Lessons can be learned from the largest tradable permit scheme to date, emissions trading now being implemented with the Kyoto Protocol. The Kyoto Protocol caps neither greenhouse gas emissions at a level that will achieve climate stability nor economic growth. If patterned after the Kyoto Protocol, cap-and-trade schemes for conservation will not ameliorate biodiversity loss either because they will not address economic growth. In response to these failures to cap economic growth, professional organizations concerned about biodiversity conservation should release position statements on economic growth and ecological thresholds. The statements can then be used by policy makers to infuse these positions into the local, national, and international environmental science-policy process when these schemes are being developed. Infusing language into the science-policy process that calls for capping economic activity based on ecological thresholds represents sound conservation science. Most importantly, position statements have a greater potential to ameliorate biodiversity loss if they are created and released than if this information remains within professional organizations because there is the potential for these ideas to be enacted into law and policy.  相似文献   
39.
Activities involving land use, land-use change,forestry, and agriculture (LUCF) can help reducegreenhouse gas (GHG) concentrations in the atmosphereby increasing biotic carbon storage, by decreasing GHGemissions, and by producing biomass as a substitutefor fossil fuels. Potential activities includereducing rates of deforestation, increasing landdevoted to forest plantations, regenerating secondaryforest, agroforestry, improving the management offorests and agricultural areas; and producing energycrops.Policymakers debating the inclusion of a variety ofLUCF activities in the Clean Development Mechanism(CDM) of the Kyoto Protocol need to consider themagnitude of the carbon contribution these activitiescould make. Existing estimates of the cumulative GHGoffset potential of LUCF activities often take aglobal or regional approach. In contrast, land-usedecisions are usually made at the local level anddepend on many factors including productive capacityof the land, financial considerations of thelandowner, and environmental concerns. Estimates ofGHG offset potential made at a local, or at mostcountry, level that incorporate these factors may belower, as well as more useful for policy analyses,than global or large regional estimates. Whilecountry-level estimates exist for forestry activities,similar estimates utilizing local information need tobe generated for agricultural activities and biofuels,as well as for the cumulative potential of all LUCFactivities in a particular location.  相似文献   
40.
The objective of this study was to assess the radiative forcing due to Finnish anthropogenic greenhouse gas emissions in three scenarios. All the Kyoto Protocol gases, i.e., CO2, CH4, N2O, and fluorinated gases, were included. The calculations showed that forcing due to Finnish emissions will increase in the case of all gases except methane by the year 2100. In 1990, radiative forcing due to Finland's emission history of all Kyoto Protocol gases was 3.2 mW/m2, of which 71% was due to carbon dioxide, 17% to methane, and the rest to nitrous oxide. In 1990 the share of fluorinated gases was negligible. The share of methane in radiative forcing is decreasing, whereas the shares of carbon dioxide and of fluorinated gases are increasing and that of nitrous oxide remains nearly constant. The nonlinear features concerning additional concentrations in the atmosphere and radiative forcing due to emissions caused by a single country or activity are also considered. Radiative forcing due to Finnish emissions was assessed with two different approaches, the marginal forcing approach and the averaged forcing approach. The impact of the so-called background scenario, i.e., the scenario for concentration caused by global emissions, was also estimated. The difference between different forcing models at its highest was 40%, and the averaged forcing approach appeared to be the more recommendable. The effect of background concentrations in the studied cases was up to 11%. Hence, the choice of forcing model and background scenario should be given particular attention.  相似文献   
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