The air we breathe has changed. The mix of gases is shifting, with more and more greenhouse gases like carbon dioxide. And this shift is happening faster each year. In fact, concentrations of CO2 have reached levels never before breathed by humans, since Homo sapiens evolved. In just a few hundred years, eons of fossilized sunshine have been burned as coal, oil and gas. The exhaust has transformed the entire atmosphere and ocean. It’s like a pollution blanket, and the result we know as climate change.
我們所呼吸的空氣已經改變了。 大氣組成成分正在改變, 大氣中有越來越多的溫室氣體, 例如二氧化碳。 而每年大氣轉變的速度也更加快速。 事實上,目前二氧化碳的濃度已高過 人類自智人進化的過去 以來所吸入的濃度。 在短短數百年內, 萬年累積而成的化石已被人類 作為燃料照亮地球, 例如煤炭、汽油及天然氣。 燃燒化石燃料所排出的廢氣 已改變了全球的大氣以及海洋。 污染就像一條毯子包覆著地球, 我們都知道的後果就是氣候變遷。
So how much more of that fossilized sunshine can we burn before further destabilizing the Earth’s systems? Not much. Think of it as a carbon budget. We are currently adding 55 billion metric tons of greenhouse gases to the atmosphere every year. This is the Gigaton Challenge. By some estimates, at that pace, we will have burned through the remaining budget by 2030. So to give us some room to breathe, the world must reduce greenhouse gas pollution by more than seven percent each year, every year of this decade ... starting now.
那麼在地球系統更惡化以前, 還有多少化石燃料能供我們使用呢? 很少。 將化石燃料想像成一種碳預算。 這幾年來,我們每年都往大氣層裡 添加了550億噸的溫室氣體。 這正是十億噸減排挑戰。 根據根據,若以這種速度, 我們將在2030年耗盡 所有的碳預算。 為了讓我們能繼續呼吸, 全球必須降低溫室氣體污染, 每年至少降低7%的溫室氣體, 從現在開始的十年間..... 每年都要達標。
There are a number of ways to do that. Let’s start by looking at the greenhouse gases themselves. CO2 makes up nearly 75 percent of the pollution emitted each year. There’s also nitrous oxide, known as laughing gas, but it's no laughing matter, seeping out of farm fields and elsewhere and making up six percent of the problem. And then there’s methane, which you may also know of as natural gas. It’s 17 percent of the total. There are other greenhouse gases, but these three make up the bulk of the climate challenge. All must be reduced -- and fast.
有很多方法能達成這項挑戰。 讓我們先從溫室氣體本身開始著手。 二氧化碳佔每年排放污染的75%。 溫室氣體也包含了一氧化二氮, 又稱為笑氣。 然而笑氣一點也不有趣, 它來自農場和其他地方, 佔污染問題的6%。 此外還有甲烷, 又稱為天然氣。 佔了總體的17%。 還有其它的溫室氣體, 然而以上三種是造成 氣候問題的主要原因。 我們必須降低這些氣體—— 而且動作要快。
Methane is better at trapping the Sun’s heat, which means cutting methane pollution is a necessary and fast-acting stimulus for our carbon budget. If methane emissions from agriculture and the oil and gas industry can be eliminated in this decade, we might be able to stave off catastrophes like the loss of the Arctic sea ice and glaciers all around the world.
甲烷善於保存陽光的熱能, 這代表降低甲烷含量是保留碳預算 必要且最快速的方式。 若能減低來自農業、 石油及天然氣產業的甲烷排放, 在這十年內, 我們也許能延緩大型災難, 例如北極海冰層融化, 以及全世界的冰川融解。
CO2 has a longer life. Once it is added to the atmosphere, it can stay up there for hundreds of years, if not longer. CO2 emissions must be cut in half by 2030, and then reduced even further by 2040, to put the world on a path of adding no CO2 to the air by 2050. And that means transforming the modern world as quickly as possible.
二氧化碳則存留較久。 一旦二氧化碳進入大氣層, 它能留存上百年, 甚至更久。 在2030年必須將 二氧化碳排量減半, 在2040進一步降低排量, 讓世界邁向正軌, 在2050年達到二氧化碳零排放。 這代表我們必須盡快轉變現代世界。
There are several ways to break down the sources of greenhouse gas emissions. Here we’re using the public Climate Watch data. Start with energy. The majority of modern energy comes from fossil fuels, which makes the energy sector 76 percent of the climate challenge, including the fuels used for transportation, industrial processes and agricultural production. The shift to clean energy must be accelerated by an order of magnitude if we want any chance to restrain global warming to 1.5 degrees Celsius. And we’ll need more ways to store this clean electricity, whether that’s putting it in the chemical bonds of a battery or into a molecule of hydrogen. Batteries and clean hydrogen are also going to play a key role in cleaning up transportation, which accounts for 17 percent of climate-changing pollution, including the use of energy to move people and goods around: eight percent from cars; five percent from trucks and other heavy-duty vehicles; and four percent from shipping and aviation. With abundant clean electricity, the world can win the race to electrify cars and create cleaner alternative fuels for trucks, ships, and even one day, airplanes.
有許多方式能根絕溫室氣體的來源。 以下我們使用了ClimateWatch 所提供的公開資料。 首先是能源。 現代能源主要來自化石燃料, 使能源問題佔了 氣候變遷因素的76%, 其中包括了運輸過程, 工業加工、 還有農業產品。 我們得以十倍的速度 加快轉換成乾淨能源的進程。 若我們希望有機會能 將全球暖化控制在攝氏1.5度內。 我們也需要更多存放乾淨電力的方式, 無論是儲存在電池的化學鍵中, 或是氫分子內。 電池與清潔氫能也將在 交通運輸中扮演關鍵角色, 交通運輸造成了17%的 氣候變遷污染, 其能源使用方面包括 人類交通及貨物運送: 其中8%來自汽車排放, 5%來自貨車或其他重型車, 船運及航空業佔據剩下的4%。 有了足夠的乾淨能源, 人類能以電動汽車贏得這場挑戰, 並為貨車創造出更乾淨的替代燃料, 還有船, 甚至在未來某天,飛機也能使用。
Then there are our lifestyles and the materials that make them possible. That’s everything from the cement and steel that go into buildings to the plastic fibers in fashion. All told, these materials account for six percent of our emissions -- on top of the energy emissions required to produce them. And we’ll need new and clean ways to make them or replace them.
接著談到我們的生活模式, 以及打造這一切的東西。 也就是所有東西, 從建造建築物的水泥及鋼鐵 到流行服飾中的塑膠纖維。 這些原料總共佔了我們 溫室氣體排放的6%—— 再加上製造這些產品所需的能源排放。 而我們將需要新的 且無污染的方式製造或取代這些產品。
Farming and animal raising also have to change as agriculture accounts for 12 percent of greenhouse gas pollution. That means everything from how and what people eat to how and what cows, chickens and pigs eat. It also means finding ways for farm fields to go from sources of greenhouse gas to places where greenhouse gases get buried. Agriculture is also the biggest direct impact people have on the plants, animals, microbes and fungi that share this planet with us. To truly solve the climate challenge, the wild world will have to be protected and restored to allow all of life’s myriad forms to flourish. A halt in cutting down forests, burning peatlands and converting coastal wetlands could prevent the release of nearly five billion metric tons of greenhouse gases each year. Restoring nearly 200 million hectares of degraded forestland, peatland and wetlands could also absorb almost another four billion metric tons. Perhaps even more importantly, the ocean has vast potential to help reduce greenhouse gases ... if we protect it.
農業與畜牧業也需要改變, 因為農業佔了12%的溫室體排放。 這些包含了人類的飲食方式及內容, 以及牛、雞跟豬的食物。 也代表了農業用地需要尋求新方式, 從溫室氣體的來源 變成掩埋溫室氣體的地方。 農業也是人類對植物、動物、微生物 和真菌所共享的這個星球中 所帶來最大也最直接的影響。 要真正解決氣候變遷, 我們必須保護與復育野生區域, 讓無數生命體蓬勃發展。 停止砍伐森林, 停止焚燒泥碳地, 並歸還沿海土地, 每年就能減少釋放 將近50億公噸的溫室氣體。 恢復將近2億公頃的退化林地, 泥炭地及濕地, 這些地區也將另外吸收 40億公噸的溫室氣體。 也許更重要的是, 海洋也將具有幫助我們 降低溫室氣體的巨大潛力...... 如果我們好好保護它的話。
Finally, there are technologies being developed to draw down CO2 from the atmosphere because we have already emitted too much. But very few of these machine forests have been deployed and they are too expensive to scale up faster right now.
最後,還有正在發展的科技, 用來提取大氣中的二氧化碳, 因為我們已經排放太多二氧化碳。 但這些機械森林數量不多, 而且現在要擴大規模所費不貲。
This is the climate challenge we face: going from adding 55 billion metric tons of greenhouse gases to the air each year, to adding zero by 2050, at the latest. The countdown begins now.
這是我們要面臨的氣候挑戰: 從每年排放550億噸溫室氣體, 最後在2050年實現零排放, 現在正式開始倒數計時。
(Music)
(音樂)
[Countdown]
[倒數計時]