人类还剩下七年时间拯救地球‏

阪本龍马 · 发表于 2009-4-29 14:33:36

如果全球温室气体的排放量不能达到稳定状态，地球将进入不可逆转的恶性循环，好莱坞影片《后天》里的世界末日浩劫场景或许真的会出现。英国气候学家比尔·麦克古尔在《7 年拯救地球》一书中警告：“从现在到2015 年，人类还剩下7 年时间拯救地球。”接受《外滩画报》专访时，他说：“全球温室气体的排放量必须达到稳定状态，否则地球将进入不可逆转的恶性循环”。

　　滔天巨浪涌进纽约，街巷瞬息淹没在汪洋之中；转瞬之间，气温骤降，浩瀚汪洋中的纽约城变成了冰封世界；茫茫冰原上，只探出了自由女神的头像……这是好莱坞影片《后天》里的经典场景，该片虚构了全球变暖带来的世界末日浩劫。

　　影星丹尼斯·奎德在片中扮演一名古气候学教授，这是该片的一个主要角色。影片中，这名教授在对史前气候进行研究后指出，温室效应导致全球变暖，这将给地球带来如上所述的灭顶之灾。事后，有人问丹尼斯·奎德，这部影片是不是太杞人忧天了？他的回答是：“影片所展示的内容是会发生的，只是时间的早晚而已。”

　　4 年后，来自英国的气候学家比尔·麦克古尔(Bill McGuire) 给出了明确的时间表—2015 年地球或许将遭遇厄运。

　　在他最新出版的《7 年拯救地球》（《Seven Years to Save the Planet: The Questions and Answers》）一书中，麦克古尔提出：从现在到2015 年，人类还剩下7 年时间拯救地球。接受《外滩画报》记者专访时，麦克古尔警告说：“未来7 年里，全球温室气体的排放量必须达到稳定状态，否则地球将进入不可逆转的恶性循环，包括战争、瘟疫、饥荒、干旱、洪水、飓风等在内的各种灾难将轮番席卷地球。”

“龙卷风将不再成为头条”

比尔·麦克古尔是英国伦敦大学的地球物理学教授、英国政府的自然灾难问题顾问。
在书中，麦克古尔描述了气候变暖带来的一系列的灾难：战争频发，为了争夺水源，世界上158 处大的河流发源地可能发生冲突；瘟疫盛行，各种致命病毒接踵而至，数10 亿人背井离乡，成为“气候难民”；冰川消融引起海平面上升，荷兰将会逐步被潮水吞噬，英国海岸线将会淹没在海水之下；洪水肆虐，动植物消失的速度越来越快，到2050 年，陆地上1/4 的植物和动物都将濒临灭绝……台风和龙卷风将会更加频繁地袭击英国和欧洲大陆。“将来，类似于龙卷风将英国伯明翰郊区撕成两半的新闻将不再成为头条。”

　　比尔·麦克古尔还警告说，如果人类的努力失败，6500 万年前小行星碰撞地球造成恐龙灭绝的灾难可能再次发生。“忘记全球恐怖主义吧，因为地震、超级火山和飓风的定时炸弹在滴答作响，它们的威胁更猛烈。”

　　麦克古尔告诉记者，该书的许多观点来源于联合国政府间气候变化专门委员会（IPCC）的第四次评估报告。他同时认为，IPCC 的报告依然偏于保守，“该报告的观点其实还是过于保守和乐观，因为它的出台本身就是各国相互让步、妥协的结果——而这才是最可怕的。”

　　无独有偶，在比尔·麦克古尔推出新书的同时，联合国政府间气候变化专门委员会主席帕乔里向欧盟发出同样的警告，他希望欧盟能够带领世界对抗全球变暖。“人类必须好好利用从现在起的7 年时间，积极作为，确保温室气体的排放量高于安全程度，否则将形成难以预期的恶性循环。”这些论述和麦克古尔的观点不谋而合。

妥协的“巴厘岛路线图”
　　
“七年拯救地球”这一说法其实并不新鲜。早在2005 年年初，美国、英国和澳大利亚联合任命的一个工作小组，也曾出台过一份与之类似的报告。“气候危机只有10 年之遥。”这份报告列出了一系列限制气候变化的有关建议，包括确保全球气温不得比工业革命之前高2℃。

　　两年后，世界银行前首席经济学家、英国政府气候变化顾问斯特恩（Stern）发布名为《气候变化的经济学》的报告，这份报告算了一笔账。在这份报告之后，大多数政府认为减少温室气体排放的所需成本是可以承受的。

　　紧接着，2007 年底，联合国政府间气候变化专门委员会发布了第四次气候评估报告。这份报告基本认定了这样一个事实，“最近50 年全球气温上升是由人类活动所导致的。”

　　这一系列报告的出台产生的最大影响是：人类终于承认全球变暖是毋庸置疑的事实；全球变暖确实是由工业化以来的人类活动所造成的；人类应该针对全球变暖采取适应性对策，努力减缓气候变化。

　　这些消息令人振奋，但比尔·麦克古尔却高兴不起来。他原本对2007 年底在巴厘岛举行的联合国气候大会充满期待，但“这次会议缺乏进展”。最后的“巴厘岛路线图”是各方妥协的结果：联合国政府间气候变化专门委员会为减少温室气体排放制定的三项硬性指标均被删除；美国要求在发展中国家实行可衡量的、可报告的和可印证的减排要求也未获通过，这意味着发展中国家可以继续在没有压力的情况下自愿减排；欧盟做出了最大让步，它甚至愿意在其他国家都不参与的情况下，独自完成上述三项硬性指标。

　　如今，比尔·麦克古尔又把希望寄托于新一轮联合国气候大会。2009 年，新一轮大会将在丹麦哥本哈根举行的。

The world may have only seven years to start reducing the annual buildup in greenhouse gas emissions that otherwise threatens global catastrophe within several decades.

That means that between Inauguration Day in January 2009 and 2015, either John McCain or Barack Obama will face the most momentous political challenge of all time.

Reflecting a consensus of hundreds of scientists around the world, the Intergovernmental Panel on Climate Change has affirmed that greenhouse gas emissions are raising the Earth's temperature. The Earth is on a trajectory to warm more than 4.5 degrees Fahrenheit by around mid-century.

Exceeding that threshold could trigger a series of phenomena: Arable land will turn into desert, higher sea levels will flood coastal areas, and changes in the convection of the oceans will alter currents, such as the Gulf Stream, that determine regional weather patterns.

Manhattan and Florida would be under water, while Nevada would have no water at all. Some Russians quip that they would welcome a more temperate climate, but they would probably be sorry to lose St. Petersburg. Countries such as Bangladesh and Mali do not have the resources to mitigate or even to adapt to the impact of climate change; millions would flee coastal flooding and the desertification of farmlands, creating instant ''climate refugees.''

The head of the Nobel Prize-winning IPCC, R.K. Pachauri, recently told us: ''The cities, power plants and factories we build in the next seven years will shape our climate in mid-century. We have to act now to price carbon and create incentives to change the way we use energy and spread technology - and thereby avert nothing less than an existential threat to civilization.''

Urgent and drastic action by the international community is required, and the United States must take the lead.

Americans produce more than four times as much carbon per capita as the Chinese; 12 times as much as Indians; and more than twice as much as citizens of Germany, France, Britain and Japan. Unless the United States acts first, it will have no credibility in persuading other countries to do their share.

To their credit, McCain and Obama support the creation of a cap-and-trade system that would limit national emissions. Trading among firms would put a price on carbon. That is an essential step toward changing industry behavior, encouraging energy conservation and providing an incentive for new technologies.

As the most powerful national economy, the United States can set an example for the world in harnessing wind and solar power; ''sequestering'' (or capturing) carbon from coal plants; and developing cellulosic ethanol and safe civilian nuclear power as alternatives to fossil fuels.

But the domestic obstacles to these and other measures are daunting. While some industries will prosper, other sectors of the economy, especially those that produce or rely on coal, steel and cement, will contract. Electricity prices will increase in the near and middle terms. Many workers and households will need help with the costs of transition.

Coping with the resulting economic and political hardships would be onerous even if the next president inherited forward-looking climate-change policies. But George W. Bush has pursued an ''anti-policy,'' based on a combination of denial, procrastination and backsliding. His successor will have to make up for lost time while also dealing with a half-trillion-dollar federal deficit, a recession and a national housing crunch, a looming health-care crisis, wars in Iraq and Afghanistan, and diplomatic showdowns with North Korea and Iran.

The winner in November will need all the help he can get - including from his opponent, who will go back to the Senate as a major voice on this and other issues. The next president will also need support from the private sector, nongovernmental organizations, academia and - crucially - citizens who recognize the consequences if they do not consent to sacrifices and changes in lifestyle.

Many Americans will accept that logic, and make real changes, only if they believe greenhouse gas emissions will affect them personally. Today's adults, even if they will not be around at mid-century, must think about the fate of their children and grandchildren.

Obama can look to his two daughters, and McCain to his four grandchildren. They are among nearly 75 million Americans - and 2.2 billion people worldwide - younger than 18. That generation will be in its 40s or 50s when one of two things happens: Either the temperature of the planet warms more than 4.5 degrees and vast regions slide toward being uninhabitable, or the wisdom of the next president and his fellow leaders around the world pays off in the ultimate reward - survival.

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* CARLOS PASCUAL and STROBE TALBOTT are, respectively, vice president for foreign policy studies and president of the Brookings Institution. They are involved in a joint project with Stanford University and New York University on global governance, including on the issue of climate change.

波茨坦气候影响研究所教授斯蒂芬·拉姆斯托夫说：“如果温室气体排放继续以目前的速度增长，那么到2100年，海平面上升将超过1米。即使减少排放，最乐观的估计也是上升1米左右。”

拉姆斯托夫是在哥本哈根举行的国际气候变化科学大会上发表上述观点的。联合国政府间气候变化问题研究小组曾于2007年预测，全球变暖可能导致海平面在本世纪上升18-59厘米。

博尔德科罗拉多大学环境研究合作研究所所长康拉德·斯特芬说：“格陵兰冰川在过去1 0年里加速融化。到2 1 0 0年，全球海平面平均上升程度约为1米，甚至更高。冰融化的差异将导致地区差别悬殊。”

他说，人类限制二氧化碳排放的行动越迅速，避免出现最可怕的后果的机会就越大。他说：“21世纪可能是世界海平面快速上升的开端。短期排放目标至关重要。”

科学家们说，在本世纪早期进行减排要比后期采取行动有效得多。

拉姆斯托夫说：“大幅减排可以使我们在2050年时迅速结束气温变化(上升)，但对于海平面上升，我们能做的并不多。我们正在研究行动计划，希望使海平面上升推迟数百年。”

联合国人类住区规划署（人居署）在对全球城市所面临的气候变化威胁进行评估后指出，目前世界各地共有3351座城市位于低海拔（海拔10米以下）的沿海地区，如果全球变暖导致海平面继续上升，它们将不同程度地受到影响.