I get to learn about lots of different plans for dealing with climate change. It’s part of my job—climate change is the focus of my work with the investment fund Breakthrough Energy Ventures—but it’s just as likely to come up over dinner with friends or at a backyard barbecue. (In Seattle, we get outside as often as we can during the summer, since we know how often it’ll be raining once fall comes.)

我了解到許多應對氣候變化的不同計劃。這是我工作的一部分——氣候變化是我在突破能源基金的工作重點但這個話題同樣可能在與朋友共進晚餐或在后院燒烤時出現。(在西雅圖，我們會盡可能多地在夏天到戶外活動，因為我們知道一旦秋天來臨，下雨會有多頻繁。)

Whenever I hear an idea for what we can do to keep global warming in check—whether it’s over a conference table or a cheeseburger—I always ask this question: “What’s your plan for steel?”

每當我聽到一個如何控制全球變暖的想法——無論是在會議桌上還是在吃芝士漢堡時——我總是會問這個問題:“你對于鋼鐵是如何打算的?”

I know it sounds like an odd thing to say, but it opens the door to an important subject that deserves a lot more attention in any conversation about climate change. Making steel and other materials—such as cement, plastic, glass, aluminum, and paper—is the third biggest contributor of greenhouse gases, behind agriculture and making electricity. It’s responsible for a fifth of all emissions. And these emissions will be some of the hardest to get rid of: these materials are everywhere in our lives, and we don’t yet have any proven breakthroughs that will give us affordable zero-carbon versions of them. If we’re going to get to zero carbon emissions overall, we have a lot of inventing to do.

我知道這聽起來很奇怪，但它為一個重要的話題打開了大門——這個話題在任何關于氣候變化的討論中都值得更多的關注。制造鋼鐵及其他材料（如水泥、塑料、玻璃、鋁和紙張）是溫室氣體的第三大來源，僅次于農業和發電。它的排放量占總排放量的五分之一，而這些排放會是最難避免的。因為這些材料在我們的生活中無處不在，而我們也還沒有任何已被證實的突破性進展，制造出我們能負擔得起的零碳材料。如果我們要實現全面零碳排放 ，我們還需要做很多創新。

Steel, cement, and plastic are so pervasive in modern life that it can be easy to take them for granted. The first two are the main reason our buildings and bridges are so sturdy and last so long. Steel—cheap, strong, and infinitely recyclable—also goes into shingles, household appliances, canned goods, and computers. Concrete—rust-resistant, rot-proof, and non-flammable—can be made dense enough to absorb radiation or light enough to float on water. (People sometimes use the terms cement and concrete interchangeably, but they’re not the same thing. You make cement first, and then you mix it with sand, water, and gravel to make concrete.)

鋼鐵、水泥和塑料在現代生活中無處不在，人們很容易把它們視為理所當然可以獲得的東西。鋼鐵和水泥是我們的建筑和橋梁如此堅固耐用的主要原因。鋼材便宜、堅硬，而且可以無限循環使用，還能用于墻面板、家用電器、罐頭食品和電腦。混凝土則防銹、防腐蝕、不易燃。它可以被制造得足夠厚實來吸收輻射，也可以被制造得足夠輕且漂浮在水面上。（人們有時把水泥和混凝土這兩個詞混用，但它們不是一回事。你需要先制作水泥，然后把它和沙子、水和砂礫混合制作成混凝土。)

The 520 floating bridge near my house sits on 77 concrete pontoons, each weighing thousands of pounds. In his book Making the Modern World, Vaclav Smil estimates that America’s interstate highway system contains about 730 million tons of concrete in the driving lanes alone.

我家附近的520浮橋坐落在77個混凝土躉船上，每個躉船重達數千磅。在《創建當代世界》（Making the Modern World）一書中，瓦茨拉夫·斯米爾（Vaclav Smil）估計，僅是美國州際公路系統的行車車道就含有7.3億噸混凝土。

As for plastics, they have a bad reputation these days—and it’s true that the amount piling up in the oceans is problematic. But they also do a lot of good. For example, you can thank plastics for making that fuel-efficient car you drive so light; they account for as much as half of the car’s total volume, but only 10 percent of its weight!  

至于塑料，它們最近名聲不好——海洋中的塑料堆積量也確實是個問題。但它們也做了很多好事。例如，你可以感謝塑料使你駕駛的節能汽車如此輕便；它們占據著汽車一半的總體積，但只有汽車重量的10%！

So how do we cut down on emissions from all the steel, cement, and plastic we’re making? One way is to use less of all these materials. There are definitely steps we should take to use less by recycling more and increasing efficiency. But that won’t be enough to offset the fact that the world’s population is growing and getting richer; as the middle class expands, so will our use of materials.

那么，我們如何削減我們生產鋼鐵、水泥和塑料所產生的排放量呢？一種方法是減少這些材料的使用。我們確實應該采取一些措施，通過更多的回收利用和更高的效率來減少其使用量。但這不足以抵消世界人口不斷增長且日益富裕的事實；隨著中產階級的擴大，我們對材料的使用量也會增大。

In a sense, that’s good news, because it means more people will be living in sturdy houses and apartment buildings and driving on paved roads. But it’s bad news for the climate. Take Africa, for example: Its emissions from making concrete are projected to quadruple by 2050. Emissions from steel could go up even more, because the continent uses so little now.

從某種意義上說，這是個好消息，因為這意味著更多的人將住在堅固的房屋和公寓樓里，出門開車有鋪好的平坦道路。但這對氣候來說是個壞消息。以非洲為例：到2050年，非洲混凝土制造過程中的排放量預計將翻兩番。鋼鐵制造的排放量可能會增長更多，因為目前非洲大陸極少使用鋼鐵。

If using less isn’t really a viable option, could we make things without emitting carbon in the first place? That is, in fact, what we’ll need to do—but there are several challenges. First, these industries require a lot of electricity, which today is often generated using fossil fuels. Second, the processes also require a lot of heat (as in thousands of degrees Fahrenheit) and fossil fuels are often the cheapest way to create that heat.

如果減少使用并不是一個切實可行的選項，我們是否可以從一開始生產時就不排放碳呢？事實上，這就是我們需要做的，但也存在一些挑戰。首先，這些行業需要大量的電力，而現在通常使用化石燃料來發電。其次，這個過程也需要大量熱量(比如數千華氏度)，而化石燃料往往是產生這種熱量最廉價的方式。

Finally—and this might be the toughest challenge of all—manufacturing some of these products involves chemical reactions that emit greenhouse gases. For example, to make cement, you start with limestone, which contains calcium, carbon, and oxygen. You only want the calcium, so you burn the limestone in a furnace along with some other materials. You end up with the calcium you want, plus a byproduct you don’t want: carbon dioxide. It’s a chemical reaction, and there’s no way around it.

最后，這可能是最艱巨的挑戰——其中一些產品的制造過程包含排放溫室氣體的化學反應。比如，要制作水泥，首先要從石灰石開始，石灰石中含有鈣、碳和氧，而你只想要鈣，于是你把石灰石和其他一些材料一起放在爐子里燒。最終你會得到想要的鈣，以及你不想要的副產品：二氧化碳。這是一個化學反應，是怎么也無法繞過去的。

All three are tough challenges, but don’t despair. Scientists and entrepreneurs are trying to solve these problems and help make zero-carbon materials that will be affordable around the world. Here are a few of the innovative approaches that I’m especially excited about:

雖然以上三個挑戰都很艱巨，但請不要絕望?？茖W家和企業家正試圖解決這些問題，并制造出全世界都能負擔得起的零碳材料。下面是一些讓我感到興奮的創新方法:

1

Carbon Capture

The idea here is to suck greenhouse gases out of the air. I think this is probably the approach we’ll have to take with cement; rather than making it without emissions, we’ll remove the emissions before they can do any damage. There are two basic approaches: One is to grab the greenhouse gases right where they’re created, such as at a cement plant (that’s called carbon capture); the other is to pull them from the atmosphere, after they’ve dispersed. That’s called direct-air capture, and it’s a big technical challenge that various companies are trying to solve. Mosaic Materials, for example, is developing new nano-materials that could make direct-air capture much more efficient and cost-effective.

1

碳捕獲

這個辦法的創意是從空氣中吸收溫室氣體。我認為這可能是針對水泥將必須采取的方法——與其讓生產過程不排放溫室氣體，不如在排放物造成損害之前就消除它。有兩種基本的方法：一種是在溫室氣體產生處就捕獲它們，比如水泥廠(這叫做碳捕獲)；另一種是在溫室氣體散開后，再將它們從大氣中捕獲，這就是所謂的直接空氣捕獲，是一個許多公司都在試圖解決的巨大技術挑戰。例如，馬賽克材料公司（Mosaic Materials）正在研發一種新型納米材料，這種材料可以使直接空氣捕獲更加高效且更具成本效益。

Electrification

2

We may be able to replace fossil fuels with electricity in some industrial processes. Boston Metal, the company profiled in the video above, is a great example; they’re working on a way to make steel using electricity instead of coal, and to make it just as strong and cheap. Of course, electrification only helps reduce emissions if it uses clean power, which is another reason why it’s so important to get zero-carbon electricity.

電氣化

2

我們也許可以在某些工業過程中用電力代替化石燃料。上面視頻中介紹的波士頓金屬公司（Boston Metal）就是一個很好的例子。他們正在研究一種用電力代替煤炭來生產鋼鐵且使其同樣堅固而便宜的方法。當然，電氣化只有在使用清潔能源的情況下才有助于減少排放，這也是獲得零碳電力如此重要的另一個原因。

3

Fuel Switching

Some industrial processes can’t easily be electrified because they require too much heat. One possible alternative is to get the heat from a next-generation nuclear plant. (As I’ve mentioned before, a company that I helped start, TerraPower, uses an approach called a traveling wave reactor that is safe, prevents proliferation, and creates very little waste. ) We also might be able to get the heat using hydrogen fuels, which can be made using clean electricity and don’t emit any carbon when they’re burned. Hydrogen fuels exist today, but they’re expensive to make and transport, so companies are trying to drive the cost down and make hydrogen fuels available at scale. The Swedish steelmaker SSAB plans to build the world’s first fossil fuel-free steel plant powered by hydrogen, which will running as a pilot project next year. ThyssenKrupp and ArcelorMittal also recently announced projects in this area.

3

燃料轉換

有些工業過程很難利用電力實現，因為它們需要的熱量太多。一個可能的替代方案是從下一代核電站獲取熱量。(正如我之前提到的，我幫助創辦的一家公司泰拉能源使用了一種叫做“行波堆”的技術，這種方法安全，可防止核擴散，而且產生的廢物很少。)我們也可以用氫燃料獲得熱量，清潔電力可以制造出氫燃料，它們在燃燒時不排放任何碳。如今氫燃料已經存在，但制造和運輸成本都很高，因此企業正試圖降低成本，并大規模生產氫燃料。瑞典鋼鐵制造商SSAB計劃建造世界上首個以氫氣為動力的無化石燃料鋼鐵廠，這將在明年作為試點項目運行。蒂森克虜伯(ThyssenKrupp)和安賽樂米塔爾(ArcelorMittal)最近也宣布了該領域的項目。

Recycling

4

On its own, recycling steel, cement, and plastic won’t be nearly enough to eliminate greenhouse gas emissions, but it will help. The best book I’ve read on recycling—yes, I’ve read more than one!—is called Sustainable Materials With Both Eyes Open, and I highly recommend it.

回收利用

4

就其本身而言，回收鋼鐵、水泥和塑料還不足以消除溫室氣體的排放，但它也會有所幫助。我讀過最好的一本關于回收利用的書——是的，我讀過不止一本!——叫做《可持續材料：睜開雙眼》，我強烈推薦。

I’m optimistic about all these areas of innovation—especially if we couple progress in these areas with smart public policies. Companies need the right incentives to phase out old polluting factories and adopt these new approaches. If all of these pieces come together, we will have a climate-friendly plan for cement, as well as steel, plastic, and the other materials that make modern life possible.

我對所有這些創新領域都感到樂觀，尤其是在將這些領域的進展與明智的公共政策結合起來的情況下。企業需要適當的激勵措施來逐步淘汰舊的污染型工廠，從而采用這些新方法。如果能將這些利好都結合在一起，我們就將有一個針對水泥、鋼鐵、塑料和其他現代生活所需材料的氣候友好型計劃。