氣候變化是一個(gè)世紀(jì)規(guī)模的全球挑戰(zhàn)，需要全球響應(yīng)。但是，領(lǐng)先國(guó)家的國(guó)家政策正在引起全球的回應(yīng)。在美國(guó)，關(guān)于聯(lián)邦立法的辯論越來(lái)越多，它將開(kāi)始解決該問(wèn)題而不會(huì)對(duì)經(jīng)濟(jì)造成嚴(yán)重?fù)p害或不公平地負(fù)擔(dān)特定地區(qū)，行業(yè)和消費(fèi)者的負(fù)擔(dān)。制定此類(lèi)法規(guī)需要對(duì)關(guān)鍵設(shè)計(jì)問(wèn)題進(jìn)行周到，客觀的投入。為了滿(mǎn)足這一需求，RFF在2006年5月組織了美國(guó)氣候政策論壇。該論壇的目標(biāo)是為立法者提供經(jīng)過(guò)嚴(yán)格審查的詳細(xì)政策選擇；政策評(píng)估的重要標(biāo)準(zhǔn)；和明確表達(dá)的關(guān)注點(diǎn)（指明不同方法的優(yōu)點(diǎn)和缺點(diǎn)）。本報(bào)告中收集的15個(gè)問(wèn)題摘要由RFF研究人員撰寫(xiě)，并通過(guò)與來(lái)自美國(guó)經(jīng)濟(jì)各個(gè)領(lǐng)域的23家公司進(jìn)行的坦率討論得到了啟發(fā)。他們?cè)噲D共同提供一個(gè)共識(shí)，以制定有效的聯(lián)邦政策。論壇并未尋求達(dá)成共識(shí)或倡導(dǎo)采取特定行動(dòng)。 在隨后的所有分析和討論中，關(guān)鍵主題是需要制定政策，這些政策應(yīng)將管理環(huán)境風(fēng)險(xiǎn)的長(zhǎng)期策略與隨時(shí)間推移適應(yīng)新信息和新發(fā)展的能力相結(jié)合。解決氣候變化也將需要大量資源，也許全球年產(chǎn)量的1％或更多用于穩(wěn)定大氣中的溫室氣體（GHG）濃度。 這兩個(gè)觀察結(jié)果激發(fā)了人們對(duì)政策的興趣，這些政策是通過(guò)提高溫室氣體排放價(jià)格來(lái)實(shí)現(xiàn)的，附加有形的市場(chǎng)價(jià)值以避免或減少這些排放。依靠定價(jià)機(jī)制作為國(guó)內(nèi)氣候政策的核心要素，有望降低整體經(jīng)濟(jì)成本因?yàn)樗鼤?huì)激勵(lì)人們?cè)谌魏蔚胤蕉伎梢岳米畋阋说臏p排方案?？紤]到即使采取有效的政策也將需要大量資源來(lái)應(yīng)對(duì)氣候風(fēng)險(xiǎn)，因此避免通過(guò)不必要地限制靈活性來(lái)增加成本的策略的論點(diǎn)令人信服。依賴(lài)定價(jià)機(jī)制還可以隨著時(shí)間的推移提供靈活性，因?yàn)閷?lái)可以通過(guò)更改一個(gè)主要參數(shù)（排放價(jià)格）相對(duì)容易地調(diào)整政策的積極性。在某些地區(qū)，尤其是在電力和運(yùn)輸領(lǐng)域，可能會(huì)實(shí)施其他政策來(lái)推廣低碳技術(shù)。更廣泛的能源政策決定，尤其是那些影響天然氣供應(yīng)，核廢料，可再生能源項(xiàng)目的選址，電網(wǎng)基礎(chǔ)設(shè)施和能源效率的決定，也將對(duì)減少溫室氣體排放的努力產(chǎn)生重要影響。這些政策可以作為對(duì) 價(jià)格政策，可能會(huì)降低實(shí)現(xiàn)特定排放目標(biāo)的成本。但是，它們也可能會(huì)與原本有效的定價(jià)政策背道而馳-最多會(huì)提高成本，而最壞會(huì)產(chǎn)生相互矛盾的激勵(lì)措施。 構(gòu)成本報(bào)告的15個(gè)問(wèn)題摘要旨在闡明立法者和監(jiān)管者在尋求制定有效的應(yīng)對(duì)政策以應(yīng)對(duì)氣候變化時(shí)面臨的重要問(wèn)題。他們的關(guān)鍵主題可以歸納為一系列問(wèn)題，概述如下。在這些問(wèn)題中，前五個(gè)問(wèn)題涉及排放定價(jià)機(jī)制的核心設(shè)計(jì)，而后三個(gè)問(wèn)題探討了針對(duì)附加政策來(lái)應(yīng)對(duì)關(guān)鍵行業(yè)中特定技術(shù)機(jī)遇（通常是獨(dú)特功能）的基本原理： ?目前，美國(guó)合適的總體溫室氣體排放目標(biāo)是什么？回答這個(gè)問(wèn)題的邏輯起點(diǎn)是權(quán)衡全球成本和穩(wěn)定大氣中GHG濃度水平的收益，制定國(guó)內(nèi)政策目標(biāo)的努力還必須面對(duì)資本，技術(shù)和體制上的限制，以及美國(guó)參與，協(xié)調(diào)和激勵(lì)其他主要經(jīng)濟(jì)體的能力和排放國(guó)。 ?單一排放定價(jià)政策應(yīng)涵蓋哪些經(jīng)濟(jì)領(lǐng)域，以及在能源供應(yīng)鏈中應(yīng)監(jiān)管與能源相關(guān)的碳排放？?在確定未來(lái)溫室氣體排放的確定性與確定未來(lái)溫室氣體價(jià)格走勢(shì)的確定性方面應(yīng)給予多少重視？ ?鑒于聯(lián)邦溫室氣體定價(jià)政策的影響在地區(qū)，行業(yè)和消費(fèi)者之間可能存在很大差異，應(yīng)如何解決該政策的分配后果？具體來(lái)說(shuō)，應(yīng)如何將稅收（在稅收體系中）或排放配額所代表的資產(chǎn)價(jià)值（在限額與交易計(jì)劃中）分配回社會(huì)？ ?該政策將如何解決國(guó)際競(jìng)爭(zhēng)力問(wèn)題？ ?國(guó)內(nèi)氣候政策應(yīng)在多大程度上為加速技術(shù)開(kāi)發(fā)和部署創(chuàng)造額外的要求和/或激勵(lì)措施（超出溫室氣體價(jià)格信號(hào)）？ ?附加政策在電力部門(mén)中扮演什么角色，包括績(jī)效標(biāo)準(zhǔn)，可再生能源投資組合標(biāo)準(zhǔn)，能效計(jì)劃以及二氧化碳（CO2）捕集和封存的激勵(lì)措施-與CO2定價(jià)政策一起發(fā)揮作用嗎？考慮到該國(guó)不同地區(qū)電力部門(mén)的各種形式的法規(guī)和燃料使用方式，如何以公平的方式分配排放配額或稅收收入？鑒于要大幅減少交通運(yùn)輸部門(mén)對(duì)溫室氣體的貢獻(xiàn)，將需要更高的標(biāo)準(zhǔn)排放價(jià)格和更長(zhǎng)的交付時(shí)間，而不是其他部門(mén)實(shí)現(xiàn)類(lèi)似的減排，車(chē)輛燃料經(jīng)濟(jì)標(biāo)準(zhǔn)，可再生或低碳燃料要求以及其他技術(shù)強(qiáng)制政策（與單一GHG一起或代替）的作用是什么？?jī)r(jià)格政策？如何以或多或少的成本效益方式設(shè)計(jì)這些策略？ 這些問(wèn)題可以為從頭開(kāi)始制定氣候政策提供框架，也可以幫助解開(kāi)并闡明現(xiàn)有提案的核心要素。具體來(lái)說(shuō)，它們可以幫助決策者和利益相關(guān)者了解給定的提案如何以及是否涵蓋關(guān)鍵基礎(chǔ)， 它可能會(huì)得到改進(jìn)，以及其各種元素是否以合理的方式組合在一起。隨著就聯(lián)邦氣候政策達(dá)成共識(shí)的努力不斷加強(qiáng)，辯論的所有各方，包括更廣泛的公眾，都提出了這種批判性思維，這一點(diǎn)越來(lái)越重要。

Climate change is a century-scale, global challenge that will require a global response. A global response, however, emerges from national policies in leading countries. In the United States, there is a growing debate about federal legislation that would begin to tackle the problem without doing serious harm to the economy or unfairly burdening particular regions, industries, and consumers. Crafting such legislation requires thoughtful, objective input on critical design issues. To meet this need, RFF organized the U.S. Climate Policy Forum in May 2006. The Forum’s objective is to provide legislators with well-vetted, detailed policy options; important criteria for policy assessment; and well-articulated concerns (specifying the strengths and weaknesses of different approaches). The 15 issue briefs collected in this report were written by RFF researchers and informed by frank discussions with 23 companies drawn from across the broad spectrum of the U.S. economy. Collectively, they attempt to provide a foundation of common understanding from which effective federal policy might be crafted. The Forum has not sought to reach consensus or advocate a particular course of action.

Throughout the analyses and discussions that follow, a key theme has been the need for policies that combine a long-term strategy for managing environmental risk with the ability to adjust, over time, to new information and developments. Addressing climate change will also require significant resources, with perhaps 1 percent or more of annual global output devoted to stabilizing atmospheric concentrations of greenhouse gases (GHGs).

These two observations motivate current interest in policies that—by placing a rising price on GHG emissions—attach a tangible market value to avoiding or reducing those emissions. Reliance on a pricing mechanism as the core element of domestic climate policy promises lower overall costs to the economy

because it creates incentives to exploit the cheapest emissions-reduction options wherever they exist. Given that considerable resources will be required to address climate risks even with efficient policies, the arguments for avoiding strategies that add to cost by unnecessarily restricting flexibility are compelling. Reliance on a pricing mechanism also provides flexibility over time because the aggressiveness of the policy can be adjusted relatively easily in the future by changing a primary parameter: the emissions price.

In some areas—particularly in the electricity and transportation sectors—additional policies are likely to be implemented to promote lower-carbon technologies. Broader energy policy decisions—particularly those that affect natural gas supply, nuclear waste, the siting of renewable energy projects, electricity grid infrastructure, and energy efficiency— will also have important consequences for efforts to reduce GHG emissions. These policies can act as complements to

a pricing policy, possibly reducing the cost of achieving a particular emissions goal. However, they can also work against an otherwise efficient pricing policy—raising costs at best and creating conflicting incentives at worst.

The 15 issue briefs that comprise this report aim to elucidate the important questions that confront legislators and regulators as they seek to develop effective policy responses to address climate change. Their key themes can be framed as a series of questions, which are summarized below. Of these questions, the first five concern the core design of an emissions pricing mechanism, while the last three explore the rationale for additional policies to address specific technology opportunities (and often unique features) in key sectors:

? What is an appropriate, overall GHG emissions objective for the United States at this time? While a logical starting point for answering this question involves weighing the

global cost and benefit of stabilizing atmospheric GHG concentrations at different levels, efforts to define a goal for domestic policy must also confront capital, technological, and institutional constraints, along with the United States’ ability to engage, coordinate with, and motivate other major economies and emitting nations.

? What sectors of the economy should be covered by a single emissions pricing policy and where in the supply chain should energy-related carbon emissions be regulated?

? How much emphasis should be placed on providing certainty about future GHG emissions versus providing certainty about the trajectory of future GHG prices?

? Given that the impacts of a federal GHG pricing policy are likely to vary considerably across regions, industries, and consumers, how should the distributional consequences of such a policy be addressed? Specifically, how should revenues (in a tax system) or the asset value represented by emissions allowances (in a cap-and-trade program) be distributed back to society?

? How will the policy address international competitiveness concerns?

? To what extent should a domestic climate policy create additional requirements and/or incentives (beyond the GHG price signal) for accelerated technology development and deployment?

? What role do additional policies in the electricity sector— including performance standards, renewable energy

portfolio standards, energy efficiency programs, and incentives for carbon dioxide (CO₂) capture and storage— play alongside a CO₂ pricing policy? How can emissions allowances or tax revenues be allocated in an equitable fashion given the varied forms of regulation and patterns of fuel use that characterize the electricity sector in different regions of the country?

Given that significantly reducing the GHG contribution from the transportation sector will require much higher

emissions prices and longer lead times than achieving similar reductions from other sectors, what is the role for vehicle fuel-economy standards, renewable or low-carbon fuel requirements, and other technology-forcing policies— either alongside or in place of a single GHG-price policy? How might these policies be designed in more or less cost-effective ways?

These questions can provide a framework for devising a climate policy from scratch, or they can help to unpack and illuminate the core elements of existing proposals. Specifically, they can help policymakers and stakeholders understand how and whether a given proposal covers key bases, how

it might be improved, and whether its various elements fit together in a sensible way. As efforts to reach consensus on a federal climate policy intensify, this kind of critical thinking by all parties to the debate, including the broader public, is increasingly important.