世界迈向气候安全的机会 会擦肩而过吗?

Today’s US-China joint announcement on climate change and energy is the most important advance on the climate change agenda in many years. While the full ramifications will only be known at the climate summit in Paris in December 2015, the two largest C02 emitters have finally spoken, and most importantly, they’ve spoken together. What they’ve said gives the world a fighting chance – and no doubt the last one – for climate safety.

美国与中国周三就气候变化和能源问题发表联合声明，这是全球气候变化议程中多年来最重要的进展。虽然其全部意义要到2015年12月巴黎气候大会上才能充分浮现，但是世界最大的两个二氧化碳排放国终于作出了表态，最重要的是他们共同作出了表态。他们所发表的声明给全球带来了一次为实现气候安全而奋斗的机会——毫无疑问也是最后一次机会。

The situation is stark. While the world’s governments agreed back in 2009 that we need to keep global warming below 2 degrees Celsius (relative to the pre-industrial era), in order to avoid massive damages from droughts, floods, extreme heat waves, and rising ocean levels, the brutal fact remains that the world is on course for a catastrophic rise of some 4 to 6 degrees by the end of the century. To avoid catastrophe, and stay below the 2 degree upper limit, CO2 emissions from energy use need to fall very sharply by mid century, and to reach net-zero emissions (“decarbonization”) by around 2070.

形势是十分严峻的。早在2009年，世界各国政府就已达成共识，必须把全球气温上升幅度限制在2摄氏度以内（与工业化时代以前相比），才能避免干旱、洪灾、极端炎热天气及海平面上升导致的重大损失。尽管如此，一个依然存在的残酷现实是，全球仍处于灾难性的升温过程中，到本世纪末气温将升高大约4到6度。为避免灾难性后果并让温度的升高保持在2度的上限之内，必须在本世纪中叶以前大幅减少因消耗能源而排放的二氧化碳，并在2070年前后达到接近零排放（也就是“脱碳”）的水平。

In short, the world will need to get almost entirely out of the fossil fuel business in the next half century or so, except for what can be continued safely with the use of carbon capture and storage (CCS). Such a deep transformation is feasible through a combination of three main steps: massive energy efficiency; a pervasive shift to low-carbon and zero-carbon electricity (notably wind, solar, geothermal, hydro, nuclear, and CCS); and the electrification of all vehicle transport and of heating and ventilation in residential and commercial buildings.

简而言之，今后半个世纪左右全球必须接近完全摆脱化石燃料，只能继续使用那些能应用碳捕获与封存技术(CCS)的安全的化石燃料。这种深层次改革可以通过三个主要步骤来实现：大力提升能源使用效率；全面转向低碳和零碳电力技术（特别是风力、太阳能、地热、水力、核能以及碳捕获与封存技术）；实现所有交通工具的电气化，以及住宅和商用建筑取暖和通风的电气化。

Two kinds of breakthrough

两大突破

First, China, the world’s largest emitter by far in absolute terms (roughly 28 per cent of the world’s CO2 emissions in 2014) has agreed a clear target to reach a peak of CO2 emissions no later than 2030, with the intention of trying to peak earlier than 2030. The US’s failure to act decisively on its own emissions for two decades has long been defended by the Senate on the basis that the US should act only if China does as well. That bottleneck and excuse is ending.

首先，中国同意设立明确目标，即二氧化碳排放量最晚在2030年达到峰值，并努力提前实现这一目标。中国是二氧化碳绝对排放量最大的国家，2014年中国约占全球二氧化碳排放量的28%。20年来美国未能在自身减排上采取果断措施，对此美国参议院的辩护理由一直是：只有中国采取了行动，美国才会采取相应措施。这一阻碍和借口已不复存在。

Second, the US-China agreement has the necessary three components for deep transformation by mid-century. The agreement calls for:

其次，美中协议包含本世纪中叶实现深层改革所需的三个必备组成部分。该协议规定了：

1) short-term commitments by both countries to 2030

1) 两国到2030年的短期承诺

2) deep decarbonization by mid-century, with the US re-stating the goal of an 80 per cent CO2 reduction by the US by 2050

2) 本世纪中叶实现深度脱碳，美国重申了2050年二氧化碳减排80%的目标

3) a massive scale-up of research, development, demonstration, and diffusion (RDD&D) of low-carbon energy technologies. Specifically, China and the US committed to joint R&D in building efficiency, clean vehicles CCS, smart cities, and other areas.

3) 大举扩大对低碳能源技术的研究、开发、示范和推广(RDD&D)。具体来说，中国和美国承诺在建筑节能、清洁能源汽车碳捕捉及碳封存、智能城市等领域展开研发合作。

What chance of success?

成功的几率有多大？

An announcement is just an announcement, of course. There are many crucial details and years of action that will make the difference between mere rhetoric and true climate safety. Both countries need to show how they intend to reach not only the short-term 2025-2030 goals, but also the mid-century deep decarbonization that is really the essence of the climate challenge. Short-term commitments are fine, but can easily be an illusion as well, with short-term steps of little long-term significance, unless the short-run measures are part of a long-term path out of carbon energy. The US and China have yet to put their cards on the table on how they intend to achieve deep decarbonization.

当然，一个声明仅是声明而已。就许多关键细节和需要持续多年的行动而言，冠冕堂皇的言辞和真实的环境安全之间是存在区别的。两国都需要展示他们打算如何实现目标，不仅是到2025-2030年的短期目标，还有本世纪中叶的深层脱碳目标，后一个才是应对气候挑战的关键。短期承诺固然不错，但容易变成一种假象，只有短期措施而缺少长远意义，除非这些短期措施是一项摆脱碳能源的长期计划的组成部分。美国和中国尚未摊牌他们打算如何实现深度脱碳。

Still, the G2 has now spoken, and together with the EU, which made its own bold announcements just recently, the world’s three biggest economies and largest emitters are now on course for a serious agreement in Paris. Others will join. The three-part structure of today’s announcement can serve as the right blueprint for a serious and historic global deal in Paris. And the arithmetic is clear: if we fail in Paris, we will fail to stay below 2 degrees. Paris is the last chance.

不过，这两个大国终于作出了承诺，再加上近期才作出大胆声明的欧盟，全球三大经济体兼三大碳排放地区终于朝着在巴黎达成重要协议的方向迈进。其他国家也会加入进来。今日这份声明的三个部分可以作为未来巴黎那份重要的、历史性的全球协议的合适蓝图。而其中的得失也很清楚：如果我们不能达成巴黎协议，我们将无法把升温幅度控制在2摄氏度以下。巴黎是最后的机会。

Not surprisingly, the incoming Republican Senate majority leader Mitch McConnell piped up immediately that he and his colleagues would oppose the deal. No doubt they will try. Yet my guess is that Mr McConnell and his buddies are soon going to learn a lesson in real democracy.

不出所料，即将上任的参议院多数派领袖、共和党人米奇•麦康奈尔(Mitch McConnell)马上放话称，他和他的同僚将反对这一协议。他们当然会反对。但我的猜想是，麦康奈尔和他的伙计们将很快领会到什么是真正的民主。

While the fossil fuel lobby may have helped finance the Republican victories last week, the US public cares about its own survival and the world that their children will soon inherit. The public has tasted reality with Superstorm Sandy, with California’s record-breaking droughts, unprecedented heat waves, and repeated flooding of the eastern seaboard. The Koch brothers may have bought some 44,000 paid ads this fall to help put favoured coal and oil candidates over the top, but they did not buy the souls of the American people, who by a large majority will be gratified today by the announcements from Beijing.

尽管共和党上周在中期选举中的胜利一定程度上或许得益于化石燃料说客提供的资金，但美国民众在乎自己的生存，在乎他们的孩子将很快继承的这个世界。气候现实已经让公众体会切肤之痛——桑迪飓风(Superstorm Sandy)、加州一次次创纪录的大旱、一次次前所未有的热浪、以及东海岸地区反复发生的洪灾。科赫(Koch)兄弟或许买下了今秋的4.4万个付费广告，帮助他们青睐的、代表煤炭和石油业利益的候选人赢得了选举，但两兄弟没有买下美国人的良心，今天听到美中在北京发表的联合声明，大多数美国人会感到高兴。

The climate is heating up but so too are the climate negotiations. Today’s announcement is a major step forward for the vast majority of humanity who are seeking a safer planet.

全球气温在升高，气候谈判的热度同样也在升高。在绝大多数希望地球变得更安全的人眼中，昨日的声明是个巨大的进步。

Jeffrey Sachs is the director of The Earth Institute at Columbia University in New York and author of ‘To Move the World: JFK’s Quest for Peace

本文作者杰弗里•萨克斯(Jeffrey Sachs)是位于纽约的美国哥伦比亚大学(Columbia University)地球研究所(Earth Institute)所长，著有《推动世界：肯尼迪对和平的追求》(To Move the World: JFK’s Quest for Peace)一书