拯救全球气候希望犹存
As the world's top climate scientists released a report full of warnings this week, they kept insisting that the world still has a chance to avoid the worst effects of climate change.
本周，世界顶级气候科学家发布了一份充满警告的报告，但他们坚持认为，世界仍然有机会避免气候变化的最坏影响。
"It is still possible to forestall most of the dire impacts, but it really requires unprecedented, transformational change," said Ko Barrett, vice chair of the Intergovernmental Panel on Climate Change.
政府间气候变化专门委员会副主席柯·巴雷特说:“预防大部分可怕的影响仍然是可能的，但这真的需要前所未有的转型变化。”
"The idea that there still is a pathway forward, I think, is a point that should give us some hope."
“我认为，前进的道路仍然存在，这一点应该给我们一些希望。”
That hopeful pathway, in which dangerous changes to the world's climate eventually stop, is the product of giant computer simulations of the world economy.
在这条充满希望的道路上，世界气候的危险变化最终会停止，这是巨大的计算机对世界经济进行仿真计算的结果。
They're called integrated assessment models.
它们被称为综合评估模型。
There are half a dozen major versions of them: four developed in Europe, one in Japan, and one in the U.S., at Pacific Northwest National Laboratory.
目前有6个主要版本:4个在欧洲开发，1个在日本，1个在美国太平洋西北国家实验室。
"What we mostly are doing, is trying to explore what is needed to meet the Paris goals." says Detlef van Vuuren, at the Netherlands Environmental Assessment Agency, which developed one of the models.
荷兰环境评估机构开发了其中一个模型，该机构的德特雷夫·凡·沃伦说:“我们主要在做的就是探索实现巴黎气候变化目标所需的条件。”
World leaders agreed in Paris to limit global warming to less than 2 degrees Celsius (3.6 degrees Fahrenheit).
世界各国领导人曾经在巴黎达成协议，将全球变暖控制在2摄氏度以内。
The planet has already warmed about 1 degree Celsius, compared to pre-industrial levels.
而与工业化前的水平相比，地球已经变暖了大约1摄氏度。
Meeting that goal will mean cutting net greenhouse gas emissions to zero within about 40 years.
要实现这一目标，就意味着要在大约40年内将温室气体净排放量降至零。
It would require profound changes; so profound, it's not immediately clear that it's even possible.
而这就需要进行深刻的变革;这场变革会是如此的深远，以至于现在还不清楚它是否可能。
That's why van Vuuren and his colleagues turned to their computer models for help.
这就是凡·沃伦和他的同事求助于计算机模型的原因。
"How is it possible to go to zero emissions?" he says.
“怎样才有可能实现零排放呢？”他说。
"That's for transport, that's for housing, that's for electricity."
“交通，房产和电力行业都得要实现才行。”
Each of these models starts with data about current sources of greenhouse emissions.
这些仿真模型中的每一个都是以当前温室气体排放来源的数据开始的。
They include cars and buses, auto rickshaws, airplanes, power plants, home furnaces and rice paddies.
它们包括汽车、公共汽车、机动三轮车、飞机、发电厂、家用火炉和稻田等。
The models also include assumptions about international trade, prices, and the costs of new technologies.
这些模型还包括对国际贸易、价格和新技术成本的假设。
Then the scientists force their virtual worlds to change course, by introducing limits on greenhouse emissions.
然后，科学家们通过限制温室气体排放，迫使这个仿真的虚拟世界改变方向。
The models then try to satisfy that requirement in the most cost-effective way, as long as it's technologically feasible and doesn't run up against limits like the supply of land or other natural resources.
然后，这些模型试图以最具成本效益的方式满足这一需求，只要它在技术上可行，而且不会违反土地或其他自然资源供应等限制。
The good news is that the models found a way to meet that target, at least in scenarios where world governments were inclined to cooperate in meeting their Paris commitments.
好消息是，这些模型找到了实现这一目标的方法，至少在世界各国政府倾向于合作履行巴黎协议承诺的情况下是这样。
In fact, according to Keywan Riahi, at the International Institute for Applied Systems, in Austria, they found multiple paths to zero carbon.
事实上，根据奥地利国际应用系统研究所的凯万·莱伊的说法，他们发现了多种实现零碳排放的途径。
"The models tell us that there are, first of all, alternative pathways possible; that there are choices available to the decision-maker," he says.
“这些模型告诉我们，首先，确实存在有可能的替代路径;决策者有很多选择，”他说。
Different models, using different assumptions, arrive at contrasting visions of the future world.
不同的模型，使用不同的假设，得出了截然不同的未来世界愿景。
But they're all dramatically different from the situation today.
但它们都与今天的情况大不相同。
Some models show people responding to higher energy prices or government regulations by changing their lifestyle.
一些模型显示，人们会通过改变生活方式来应对更高的能源价格或政府监管。
They move to more energy-saving houses, and give up their cars in favor of a new and better kind of public transit.
他们会搬到更节能的房子里，放弃自己的汽车，选择一种新的更好的公共交通工具。
In addition to traditional bus lines, autonomous vehicles respond like Uber — taking people where they need to go.
除了传统的公交线路，自动驾驶汽车会像优步一样随叫随到——把人们带到他们需要去的地方。
Riahi likes this version best.
莱伊最喜欢的就是这个版本。
"I'm convinced that a fundamental demand-side restructuring would also lead to a better quality of life," he says.
他表示:“我相信，从根本上对需求进行重组，也会提高我们的生活质量。”
Other scenarios show people still using plenty of energy, which in turn requires a huge boost in production of clean electricity.
其他的仿真模拟显示，人们仍在使用大量能源，而这反过来又需要大幅提高清洁电力的生产。
It would mean 10 or 20 times more land covered with solar and wind farms, compared to now, plus more power plants burning wood or other biofuels, outfitted with equipment to capture and store the carbon dioxide that's released.
这将意味着必须有比现在多10到20倍的土地被太阳能和风能农场覆盖，再加上更多的燃烧木材或其他生物燃料的发电厂，配备收集和储存释放出的二氧化碳的设备。
#问题#
文中提到巴黎气候协议规定的要控制全球气温上升的上限是多少？
留言回复正确答案，前五名朋友可以获得红包奖励哦，赶快来试试吧！
感谢关注
跟Amber一起看世界