United Nations Secretary-General Ban Ki-moon has rightly declared sustainable development to be at the top of the global agenda. We have entered a dangerous period in which a huge and growing population, combined with rapid economic growth, now threatens to have a catastrophic impact on the earth’s climate, biodiversity, and fresh-water supplies. Scientists call this new period the Anthropocene – in which human beings have become the main causes of the earth’s physical and biological changes.
The Secretary-General’s Global Sustainability Panel has issued a new report that outlines a framework for sustainable development. The GSP rightly notes that sustainable development has three pillars: ending extreme poverty; ensuring that prosperity is shared by all, including women, youth, and minorities; and protecting the natural environment. These can be termed the economic, social, and environmental pillars of sustainable development, or, more simply, the “triple bottom line” of sustainable development.
The GSP has called for world leaders to adopt a new set of Sustainable Development Goals, or SDGs, that will help to shape global policies and actions after the 2015 target date for achieving the Millennium Development Goals (MDGs). Whereas the MDGs focus on reducing extreme poverty, the SDGs will focus on all three pillars of sustainable development: ending extreme poverty, sharing the benefits of economic development for all of society, and protecting the Earth.
It is, of course, one thing to set SDGs and quite another to achieve them. The problem can be seen by looking at one key challenge: climate change. Today, there are seven billion people on the planet, and each one, on average, is responsible for the release each year of a bit more than four tons of carbon dioxide into the atmosphere. This CO2 is emitted when we burn coal, oil, and gas to produce electricity, drive our cars, or heat our homes. All told, humans emit roughly 30 billion tons of CO2 per year into the atmosphere, enough to change the climate sharply within a few decades.
By 2050, there will most likely be more than nine billion people. If these people are richer than people today (and therefore using more energy per person), total emissions worldwide could double or even triple. This is the great dilemma: we need to emit less CO2, but we are on a global path to emit much more.
We should care about that scenario, because remaining on a path of rising global emissions is almost certain to cause havoc and suffering for billions of people as they are hit by a torrent of droughts, heat waves, hurricanes, and more. We have already experienced the onset of this misery in recent years, with a spate of devastating famines, floods, and other climate-related disasters.
So, how can the world’s people – especially its poor people – benefit from more electricity and more access to modern transportation, but in a way that saves the planet rather than destroys it? The truth is that we can’t – unless we improve dramatically the technologies that we use.
We need to use energy far more wisely while shifting from fossil fuels to low-carbon energy sources. Such decisive improvements are certainly possible and economically realistic.
Consider the energy inefficiency of an automobile, for example. We currently move around 1,000 to 2,000 kilograms of machinery to transport only one or just a few people, each weighing perhaps 75 kilograms (165 lbs.). And we do so using an internal combustion engine that utilizes only a small part of the energy released by burning the gasoline. Most of the energy is lost as waste heat.
We could therefore achieve huge reductions in CO2 emissions by converting to small, lightweight, battery-powered vehicles running on highly efficient electric motors and charged by a low-carbon energy source such as solar power. Even better, by shifting to electric vehicles, we would be able to use cutting-edge information technology to make them smart – even smart enough to drive themselves using advanced data-processing and positioning systems.
The benefits of information and communications technologies can be found in every area of human activity: better farming using GPS and micro-dosing of fertilizers; precision manufacturing; buildings that know how to economize on energy use; and, of course, the transformative, distance-erasing power of the Internet. Mobile broadband is already connecting even the most distant villages in rural Africa and India, thereby cutting down significantly on the need for travel.
Banking is now done by phone, and so, too, is a growing range of medical diagnostics. Electronic books are beamed directly to handheld devices, without the need for bookshops, travel, and the pulp and paper of physical books. Education is increasingly online as well, and will soon enable students everywhere to receive first-rate instruction at almost a zero “marginal” cost for enrolling another student.
Yet getting from here to sustainable development will not just be a matter of technology. It will also be a matter of market incentives, government regulations, and public support for research and development. But, even more fundamental than policies and governance will be the challenge of values. We must understand our shared fate, and embrace sustainable development as a common commitment to decency for all human beings, today and in the future.
Jeffrey D. Sachs is Professor of Economics and Director of
the Earth Institute at Columbia
University.
He is also Special Adviser to United Nations Secretary-General on the
Millennium Development Goals.
Jeffrey D. Sachs: 可持續人道精神
亞的斯亞貝巴——可持續發展的意思是實現人人得益的經濟增長，同時又保護地球的寶貴資源。但是，當前的全球經濟是不可持續的，10億以上的人口沒有趕上經濟進步進程，地球環境也因人類活動而受到了可怕的傷害。可持續發展要求動員受共同價值指導的新技術。
聯合國秘書長潘基文正確地指出，可持續發展是全球日程的重中之重。我們已經進入了一個危險的時期，人口數量龐大且在不斷增長，經濟增長十分迅速，因而對地球氣候、生物多樣性和清潔水供給造成了災難性影響。科學家將這一新時期稱為“人類紀”（Anthropocene），即人類稱為地球物質和生物變化的主要原因的時期。
潘基文的全球可持續發展委員會（Global Sustainability Panel，GSP）發布了一份新報告，列出了一個可持續發展框架。GSP正確地指出，可持續發展有三大支柱：終結極端貧困、保証繁榮為所有地球人所共享（包括婦女、年輕人和少數民族），以及保護自然環境。它們分別可以稱為可持續發展的經濟、社會和環境支柱，或統稱為“三條基線”。
GSP呼吁世界領導人採用新的可持續發展目標（Sustainable Development Goal），簡稱SDG，從而在千年發展目標（Millennium Development
Goals，MDG）於2015年到期后制定新的全球政策。MDG專注於削減極端貧困，而SDG將專注於可持續發展的三大支柱：終結極端貧困、讓全社會分享到經濟發展的好處，以及保護地球。
當然，設置SDG是一回事，實現它們又是另一回事。其中的問題可以從一大關鍵挑戰中一窺端倪：氣候變化。如今，地球人口已經突破了70億，平均而言，每個人每年要向大氣排放4噸二氧化碳。這些二氧化碳產生於我們燃燒煤、石油和汽油來生產電力、發動汽車或室內取暖的過程中。總的來說，人類每年要向大氣層排放300億噸二氧化碳，足以在短短幾十年間讓氣候發生急劇變化。
到2050年，地球人口極有可能將突破90億。如果那時的地球人比今天更富有（因而人均能源使用量也更多），那麼世界總排放量將可能增長一倍甚至兩倍。這就造成了一個兩難困境：我們需要減少二氧化碳的排放，但腳下的路卻通向更多的排放。
我們必須認真對待這一情景，因為沿著增加全球排放之路走下去幾乎肯定造成一場大浩劫，數十億人口將因干旱、熱浪、颶風等災難遭受苦難。近幾年來，我們已經在經歷這一浩劫的起始階段，飢荒、洪水和其他與氣候有關的災難輪番不斷地襲擊著地球。
那麼，世界人民——特別是貧困人口——如何從更多的電力和更現代的交通中獲益，同時又實現對地球的拯救而不是破壞呢？答案是我們無法做到這一點，除非我們能夠極大地改良我們所使用的技術。
我們需要更加精明地使用能源，同時從化石燃料轉向低碳能源。在這方面的決定性改良是可實現的，而且具有經濟上的現實性。
比如，我們可以考慮一下汽車能效問題。目前，我們正在使用1 000到2 000公斤的機器運送一個或數個人，每個人的重量大約為75公斤。汽車所使用的內燃機隻能利用汽油燃燒所釋放的能量的一小部分。大部分能量以廢熱的形式浪費掉了。
因此，我們可以使用又小又輕、以電池作為能源的汽車，採用高效的電動馬達，使用太陽能等低碳能源。更妙的是，使用電動汽車，我們可以用高精尖信息技術使它們智能化，甚至通過高級數據處理技術和定位系統實現自動駕駛。
信息和通信技術所帶來的好處可以在人類活動的所有領域看到：GPS和滴灌技術所帶來的農業進步、精密制造、能自動實現節約能源的建筑，更不用說消除距離隔閡的互聯網了。移動寬帶已能將最偏遠的非洲和印度農村互聯起來，從而大大降低差旅需要。
如今，銀行業務也可以通過電話實現，越來越多的醫療診斷也是如此。電子書出現在各式各樣的手持設備中，你不再需要跑到書店去，制作圖書也不再需要用紙漿。教育也越來越在線化了，很快，各地的學生就能以幾乎為零的（增加學生人數的）“邊際成本”獲得一流的教學服務。
但從現階段邁向可持續發展光靠技術是不行的。市場激勵、政府監管以及對研發的公共支持也是必不可少的。但是，比政策和治理更基本的問題是價值挑戰。我們必須理解我們的共同命運，以悲天憫人的胸懷將可持續發展作為共同承諾，讓今天和明天變得更好。
Jeffrey D.
Sachs是哥倫比亞大學經濟學教授，地球研究所主任，也是聯合國秘書長千年發展目標特別顧問。