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A Stern warning on global warming

Britain’s landmark review of the economics of climate change is clear: act now or pay a far higher price later. Maryann Bird highlights Nicholas Stern’s findings.

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“The scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response.”

That blunt, no-nonsense sentence begins the executive summary of a nearly 600-page independent British review of the economics of climate change released on 30 October 2006. (Because of its global import, a short summary has also been produced in Chinese and several other languages.) Known as the Stern Review, the long-awaited study by former World Bank chief economist Nicholas Stern considers the economic costs of the impacts of climate change, along with the costs and benefits of action to reduce emissions of the greenhouse gases (GHG) linked to that change.

Commissioned in July 2005 by Gordon Brown, Britain’s chancellor of the exchequer, the report asserts that “the benefits of strong, early action on climate change outweigh the costs.” Taking a global and long-range perspective, it states: “What we do now can have only a limited effect on the climate over the next 40 or 50 years. On the other hand, what we do in the next 10 or 20 years can have a profound effect on the climate in the second half of this century and in the next.”

“There is still time to avoid the worst impacts of climate change, if we act now and act internationally,” Stern said in releasing what he termed an “essentially optimistic” review in London. “Governments, businesses and individuals all need to work together to respond to the challenge. Strong, deliberate policy choices by governments are essential to motivate change. But the task is urgent. Delaying action, even by a decade or two, will take us into dangerous territory. We must not let this window of opportunity close.”

In summary, the Stern Review concluded:

There is still time to avoid the worst impacts of climate change, if we take strong action now.

“Climate change,” the study says, “will affect the basic elements of life for people around the world – access to water, food production, health and the environment. Hundreds of millions of people could suffer hunger, water shortages and coastal flooding as the world warms.”

Based on formal economic models, Stern estimates that, without action, “the overall costs and risks of climate change will be equivalent to losing at least 5% of global GDP each year, now and forever.” It adds, ominously, that if a wider range of risks and impacts were included, “the estimates of damage could rise by 20% of GDP or more.” In contrast, however, the costs of action (reducing GHG emissions to avoid climate change’s worst impacts) “can be limited to around 1% of global GDP each year.”

“Our actions now and over the coming decades could create risks of major disruption to economic and social activity, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century. And it will be difficult or impossible to reverse these changes.”

The response, says Stern, must be prompt, strong and international. It also needs to be based on “a shared vision of long-term goals and agreement on frameworks that will accelerate action”, and it must build on “mutually reinforcing approaches” at regional, national and international levels.

Climate change could have very serious impacts on growth and development.

GHG concentrations could reach twice pre-industrial levels as early as 2035 if no action is taken to reduce them, “virtually committing us to a global average temperature rise of over 2ºC” and more than a 50% longer-term chance that the rise would exceed 5ºC.

“This rise would be very dangerous indeed,” says the report, as it would be “equivalent to the change in average temperatures from the last ice age to today.” It would lead to radical changes in where and how people live: “human geography”. Even at more moderate warming levels, serious impacts on world output, human life and the environment would occur. These changes – including floods, droughts and storms –already are occurring, and would affect all countries. “The most vulnerable – the poorest countries and populations – will suffer earliest and most, even though they have contributed least to the causes of climate change.”

Stern makes clear that while it is no longer possible to prevent the climate change that will take place over the next 20 to 30 years, adaptation is essential. “[I]t is still possible to protect our societies and economies from its impacts to some extent – for example, by providing better information, improved planning and more climate resilient crops and infrastructure.” While these efforts “will put still further pressure on already scarce resources,” they should be accelerated. In developing countries alone, the price-tag for adaptation will be tens of billions of US dollars a year.

The costs of stabilising the climate are significant but manageable; delay would be dangerous and much more costly.

Climate change’s worst impact-risks can be greatly reduced if GHG levels can be stabilised between 450 and 550 parts per million of carbon dioxide equivalent (CO2e). The level is now at 430 ppm and rising by over 2 ppm annually. Such stabilisation would require that emissions be reduced by at least 25% below current levels by 2050 – and ultimately to more than 80% below current levels.

“This is a major challenge,” Stern acknowledges, “but sustained long-term action can achieve it at costs that are low in comparison to the risks of inaction. Central estimates of the annual costs of achieving stabilisation between 500 and 550 ppm CO2e are around 1% of global GDP, if we start to take action now.” Future costs, whether higher or lower, will depend on levels of efficiency gains, co-benefits such as air-pollution reduction, low-carbon technology innovations and economic instruments related to emissions cuts.

Says the report: “It would already be very difficult and costly to aim to stabilise at 450 ppm CO2e. If we delay, the opportunity to stabilise at 500-550 ppm CO2e may slip away.”

Action on climate change is required across all countries, and it need not cap the aspirations for growth of rich or poor countries.

The costs of acting are unevenly distributed across sectors and around the world. “Even if the rich world takes on responsibility for absolute cuts in emissions of 60-80% by 2050, developing countries must take significant action, too,” says the review. But developing countries will not have to bear the full costs of their action alone. Stern notes that carbon markets in rich countries already are starting to deliver finance routes – such as the Kyoto Protocol’s Clean Development Mechanism -- to support low-carbon development. However, a “transformation of these flows is now required to support action on the scale required.”

As new markets in low-carbon technologies and goods and services spring up, actions on climate change will also create “significant” business opportunities. “The world does not need to choose between averting climate change and promoting growth and development,” the review says. “Changes if energy technologies and in the structure of economies have created opportunities to decouple growth from greenhouse gas emissions. Indeed, ignoring climate change will eventually damage economic growth.”

The pro-growth strategy for the longer term, Stern adds, is tackling climate change – which can be done in a way that does not cap any countries’ aspirations for growth.

A range of options exists to cut emissions; strong, deliberate policy action is required to motivate their take-up.

Increased energy efficiency, changes in energy demand, and adoption of clean power, heat and transport technologies all can help cut emissions. The global power sector, says the review, “would need to be at least 60% decarbonised by 2050 for atmospheric concentrations to stabilise at or below 550 ppm CO2e, and deep emissions cuts will also be required in the transport sector.”

Even with strong growth in the use of renewable energy and other low-carbon sources, “fossil fuels could still make up over half of global energy supply in 2050.” As coal will continue to be important in the world’s energy mix, however, “extensive carbon capture and storage will be necessary to allow the continued use of fossil fuels without damage to the atmosphere.” Reductions in non-energy emissions, as from deforestation, agriculture and industry, also are deemed essential. The economies of both developing and developed countries can grow as emissions are reduced and stabilised, provided that strong, deliberate policy choices are made.

“Climate change is the greatest market failure the world has ever seen,” says the review, “and it interacts with other market imperfections.” An effective global response requires: the pricing of carbon, implemented through tax, trading or regulation; policy to support innovation and deployment of low-carbon technologies; and action to remove energy-efficiency barriers and to educate individuals about their part in responding to climate change.

Climate change demands an international response, based on a shared understanding of long-term goals and agreement on frameworks for action.

Although countries and regions – including the China, the European Union and California – are taking action against GHG emissions now, and the UN Framework Convention on Climate Change, the Kyoto Protocol and other approaches and partnerships are providing a basis for international cooperation, more ambitious action is needed globally.

“Each country, however large, is just a part of the problem,” the review asserts. “It is essential to create a shared international vision of long-term goals, and to build the international frameworks that will help each country to play its part in meeting these common goals.”

Key elements of these future frameworks, Stern says, should include: expanding and linking emissions trading schemes around the world; greater technology cooperation, including a doubling of support for energy research and development, plus a near-quintupling of new low-carbon technologies; action to reduce deforestation, which contributes more to annual global emissions than the transport sector; and adaptation to climate change, including research into new, more resilient crop varieties and the integration of climate change into development assistance policies.

What Stern has done in his report is “remarkable,” wrote Michael McCarthy, environment editor of the Independent newspaper. “He has ripped up the last excuse for inaction. The scientific case to fight climate change has long been overwhelming, the moral case even more so. The last rational place where an opponent of acting to tackle global warming might take refuge has been the economic argument. No longer. If you oppose action now, you are simply burying your head in the sand.”


Maryann Bird is a London-based journalist with a special interest in environmental and human-rights issues. A writer and editor, she was previously a staff member at Time magazine (Europe), The Independent, the International Herald Tribune and The New York Times.

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Default avatar
匿名 | Anonymous




I can't helping thinking that Stern doesn't go far enough. Is capitalism really compatible with protecting the environment?

Default avatar
匿名 | Anonymous


也许这个问题应该是:资本主义本身能够和保护环境和谐吗? 对我来说,经济讨论也许能够很好地得到资助,但是如果没有一个相关的经历充沛的道德讨论,我们永远也不可能得到个人和政府关于环境变化的承诺。

re: really?

Maybe the question should be - is capitalism _alone_ compatible with protecting the environment? It seems to me that the economic arguments may well be well-founded, but without a correspondingly robust moral argument - we'll never get the personal and governmental commitments we need to really act on climate change.

Default avatar
匿名 | Anonymous


尽管斯特恩报告已经清楚地指出不采取行动将会付出的沉重代价,但恐怕英国政府将方案付诸行动不说好几十年,只好也得等上好几年。计划之一就是将碳贸易延伸到个人,但是我最近访谈到的这一方案发展实施方面的两个主要负责人都表示实施这一方案还需要多方面的研究。我被告知这是一种媒体辞令策略。这项计划的完全实施估计还需要五年。其中有一个非常重要的问题在报告中没有被提及,就是关于碳排放限额卡的安全管理问题。我相信还有两个至关重要的领域在与中国的携手合作下我们可以做出迅速提高。第一个是减少能源浪费;我们已经不再生活在使用廉价能源的时代了,但是旧的浪费习惯还很难改变,尤其是英国商业和政府造成的浪费。广告和店铺招牌不分昼夜地亮着,公共建筑过多的照明设备,大型办公楼彻夜照明以便清洁工工作,而且清洁工也不能随意开关灯,还有无数的店铺橱窗都是彻夜灯火辉煌。再加上上百万的交通灯,依旧使用白炽灯泡。而中国工业生产已经换上了特制的发光二极管系统,至少有一家核电站被关闭。每一家商铺,每一个家庭做出的每一个小小改变都将会积少成多,引起减少排放的巨大改变。但是还有一个问题就是,中国多项大型的和不断扩大的荧光灯及二级发光管生产合同却并没有英国的影子。这么说英国并没有打算换上节省能量的照明设备。第二个方面是可更新能源和提高能源效率的研究;目前的研究主要是受到竞争的驱使和强有力的游说的结果。美国和欧洲越来越多的国家支持玉米燃料乙醇,但是强有力的科学证据证明了这是一个错误的生物燃料发展方向。竞争是一个寻求新发明的好办法,但却不能成为气候变化所需要的全球合作的动力。有价值的发明没能获得游说联合会的支持,新科技被忽略。我们需要对我们整个生活和商业方式做出行为性的改变。--- Roy Tindle (Roy是一名能源研究员,公司顾问,英国工党智囊团成员,英国游说联合会Aldersgate Group成员)

Stern Inaction

The Stern Review points very clearly to the cost of inaction but I fear that we will continue to see the UK Government propose actions that will take years, if not decades, to put into action.

One of the first suggestions is the extension of carbon trading to the level of the individual citizen but when I recently talked to two of the leaders in the field of developing this scheme they confessed to many areas of research that are yet needed. I was told that this is a medium term policy: I see another 5 years before implementation. The very significant factor of carbon card security wasn’t mentioned in the discussion!

I believe that there are two significant areas where we could make immediate progress, both with Chinese cooperation. The first is stopping energy waste. We are living just beyond the era of cheap energy and the old wasteful habits die hard. I point specifically to the energy wasted by UK business and government. Adverts and shop signs that continue to be lit in bright daylight, excessive lighting in public buildings, large office buildings that are lit throughout the evening for cleaners who, apparently, are not able to turn lights on and off again and the countless shop displays that are illuminated throughout the night. Add traffic lights, tens of millions of them, which still use incandescent bulbs. Chinese industry can replace with custom LED units and at least one power station could be turned off.

Change can be made incrementally, each small change aggregating business on business, home on home to produce a very significant cut in emissions.

There is one problem, however, most of the large and increasing range of compact fluorescent lamps and LEDs that are being produced in China do not reach the UK. So replacement doesn’t happen.

The second aspect is that of research in renewable energy and, of equal importance, energy efficiency. Currently such is research is mainly driven by competition and supported by powerful lobbies. In the USA and to a growing extent in Europe, increasing claims are being made for corn ethanol but there is very strong scientific evidence that this is the wrong biofuel route. Competition is good to fine tune invention but a problems of the scale of climate change requires international cooperation as the driver. Worthwhile inventions cannot find support against existing lobbies and new techniques are overlooked.

We need behavioural change that takes in the entirety of our lives and of the way in which we do business.

Roy Tindle.

Roy is an energy researcher, adviser to Compass, a UK Labour think tank, and a member of the Aldersgate Group.

Default avatar
匿名 | Anonymous



carbon trading

In the report it mentioned CDM and emissions trading. are these systems really working on tackling on climate change? don't they even create incentives to pollute?