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課程來源:TED
     

 

Jonathan Foley 談另一個棘手的事實

Jonathan Foley: The other inconvenient truth

 

Photo of three lions hunting on the Serengeti.

講者:Jonathan Foley

2010年10月演講,2012年4月在TEDxTC上線

 

翻譯:洪曉慧

編輯:朱學恆

簡繁轉換:洪曉慧

後製:洪曉慧

字幕影片後制:謝旻均

 

影片請按此下載

MAC及手持裝置版本請按此下載

閱讀中文字幕純文字版本

 

關於這場演講

糧食的迫切需求意味著農業已成為導致氣候變遷、生物多樣性喪失及環境破壞的最大因素。在 TEDxTC中,Jonathan Foley闡述為何我們亟需著手進行「terraculture」-即全球耕作。(攝於TEDxTC)

 

關於Jonathan Foley

Jonathan Foley研究複雜環境系統及其對社會的影響。他的計算機模型顯示農業對地球的深刻影響。

 

為什麼要聽他演講

Jonathan Foley博士致力於研究全球環境系統與人類文明的複雜關係,利用計算機模型分析全球土地利用的變化、生態系統及環境資源。Foley曾經於威斯康辛大學任教15年,目前是明尼蘇達大學生態系教授和McKnight首席講座,及環境研究所所長。

 

Jonathan Foley的英語網上資料

Website: Institute on the Environment

Website: Global Landscapes Initiative

Website: Momentum

Twitter: @GlobalEcoGuy

Facebook: GlobalEcoGuy

 

[TED科技‧娛樂‧設計]

已有中譯字幕的TED影片目錄(繁體)(簡體)。請注意繁簡目錄是不一樣的。

 

Jonathan Foley 談另一個棘手的事實

今晚我想談一個令人震驚的全球議題,即土地利用、糧食和環境的關係,某些和每個人都息息相關的事物,我稱之為「另一個棘手的事實」。

 

但首先我想帶領大家進行一趟簡短的旅程,先參觀一下我們的星球,不過是在夜間,從外太空觀看。這是從外太空觀察地球夜間的景象。如果你搭乘人造衛星繞行地球,你首先注意到的是-當然,人類主宰地球的程度。我們看見城市、油田,你甚至能辨識出海上的漁船隊。我們主宰大部分地球,主要藉由能源的運用,如我們夜間所見的景象。但我們回頭稍做深入研究,觀察白晝的情形。我們於白晝所見的是地表景觀。

 

這是亞馬遜盆地中一個叫朗多尼亞的地方,位於巴西亞馬遜盆地南部。如果你仔細觀察右上角處,會看見一條白色細線,那是興建於1970年代的道路。如果我們回顧2001年同地區的景觀,會發現這些道路四處延伸,然後延伸出更多道路,道路盡頭是雨林中的小空地,豢養著一些牛。這些牛將變成牛肉,進入人類腹中。基本上這些牛肉將運往南美,供巴西人和阿根廷人食用,不會運往這裡。但我們會在熱帶地區發現許多這種森林經砍伐後的魚骨狀圖案,尤其是這片區域。

 

如果這趟世界之旅稍微往南前進,可抵達亞馬遜盆地與玻利維亞交界處,這同樣是1975年的景觀。如果仔細觀察,會看見一條白色細線穿過一道類似細縫的地方,原始叢林中有一位孤獨的農夫。我們再回顧一下數年後的情景。這是2003年的景觀,我們所見的景觀十分類似愛荷華州,而非雨林。事實上你所見的是黃豆田,這些黃豆將運往歐洲和中國,作為動物的飼料,尤其是大約十年前,狂牛症爆發後,我們不想再使用動物性蛋白質餵食動物,因為這將造成疾病傳播。相反地,我們希望以較多的植物性蛋白質餵食動物,因此黃豆需求激增,顯示貿易和全球化確實與雨林和亞馬遜盆地息息相關-這些對我們來說十分陌生且與世隔絕的地區。

 

好,環繞世界的旅程中,我們一再發現無數景觀遭受破壞,轉變成糧食和其他作物產地。

 

因此我們常被問到的問題是:世上有多少土地被用於生產糧食?這些地方位於何處?未來將發生何種改變?這代表什麼意義?好,我們的團隊觀察全球情況,利用人造衛星蒐集的資訊和地表資料追蹤全球農地規模,這是我們的發現,令人震驚不已。這張地圖顯示農業分布於地表的情形。綠色區域是種植作物的地方,例如小麥、黃豆、玉米或稻米等,相當於1600萬平方公里土地。如果將這些土地集中在同一處,大約相當於南美洲面積。第二片以咖啡色表示的區域是牧地或放牧區,動物生活於此,這片區域大約3000萬平方公里,相當於非洲面積。十分廣大的土地,也是最肥沃的土地。如你們所見,其餘部份為撒哈拉沙漠、西伯利亞或雨林深處,我們已使用了相當於整個地球的土地。如果仔細觀察,將發現大約 40% 的地表貢獻於農業,比令我們怨聲載道的居住地大60倍,包括郊區和大多數人類居住的城市。目前世上有半數人口居住於城市,但生產糧食的土地比人類居住地大60倍,這是十分驚人的事實,令觀察到這一點的我們震驚不已。

 

因此我們將十分廣大的土地用於農業,但也因此消耗大量水源。這是亞利桑那州空照圖,當你目睹這幅景象時,會想,「他們在這裡種什麼?」事實上他們在沙漠中種植萵苣,用噴灑方式供應水源。諷刺的是,這些產品或許正於雙子城超市貨架上販售。但令人感趣的是,這些水源必定來自某處-來自此處,北美的科羅拉多河。好,這是1950年代科羅拉多河平日景象;沒有洪水、沒有乾旱,它平日的景象如照片所示。但如果觀察目前情況,這是同一地點、在一般情況下僅剩的水流。不同之處主要在於河水用來灌溉沙漠中的作物,或斯科茨谷的高爾夫球場,隨你想像。好,這得消耗大量水源。同樣地,我們開採水源用於種植作物。如果現在朝科羅拉多河下游前進,它已完全乾涸,不再流向海洋。我們為了灌溉作物,將北美整條河流消耗殆盡。

 

好,這並非世上最糟的情況,最糟的情況或許發生在鹹海。在座大多數人或許記得地理課中曾經學過,它位於前蘇聯,介於哈薩克與烏茲別克之間,是世上最大的內陸湖之一。但其中有個弔詭處,因為它看起來彷彿被沙漠包圍。為何它會出現在此處?它出現在此處的原因是,你看見右側有兩條穿越沙漠的小河,供應這片低窪處水源,河川匯集東部遠處山脈的融雪,積雪融化後,流向穿越沙漠的河川,形成廣大的鹹海。好,1950年代,蘇聯決定將河水改道,引入哈薩克沙漠地帶種植棉花-信不信由你-將棉花販售到國際市場,替蘇聯賺取外匯,他們亟需這些收入。好,你可以想像會發生什麼事。截斷鹹海的水源會發生什麼事?這分別是1973年、1986年、1999年、2004年和大約11個月前的情形。確實十分驚人。現場許多聽眾住在中西部,不妨將它想像成蘇必利爾湖或休倫湖。這是十分驚人的改變。

 

不僅是水量或海岸線的改變,而是這片區域環境本質上的改變。這麼說吧,蘇聯沒有塞拉俱樂部(環保團體),不妨以這個觀點來看。因此,你會發現鹹海底部不甚美觀,存在許多毒性廢棄物,許多棄置於此的物品現在已逐漸分解到大氣中。其中一個離岸甚遠且難以抵達的小島,曾經是蘇聯生化武器測試地點,現在你可以步行到那裡。氣候形態已發生變化,鹹海獨有的20種魚類中,19種已在地球上消失蹤影,這是一場環境大浩劫。

 

我們試著深入瞭解一下。這是幾年前高爾(美國前副總統)給我的一張照片,他很久以前在蘇聯拍攝的景觀,顯示擱淺於鹹海中的漁船隊。你看見他們挖的水道嗎?他們費盡心力,試著讓船漂浮在僅剩的湖水中,但他們最後不得不放棄,因為碼頭和停泊處的開鑿無法跟上海岸線倒退的速度。我不知道你們的想法,但我擔心未來考古學家會挖出這些東西,將這個時代的情形寫入歷史,疑惑地想,「你們到底在想什麼?」好,這就是我們即將面臨的未來。

 

我們已使用了地球上現有的 50% 淡水,光是農業部分就佔用了70%,因此我們在農業上消耗許多水源和土地,我們也在農業上消耗許多大氣。當我們談到大氣時,通常會聯想到氣候變遷和溫室氣體,大多與能源有關,但事實上農業亦是溫室氣體最大來源之一-如果考量焚燒熱帶雨林所產生的二氧化碳,或牛群和稻米所產生的甲烷,或大量肥料所產生的一氧化二氮。事實上,在人類活動當中,排放至大氣層的溫室氣體 30% 來自農業,遠大於所有交通工具、所有電力設施及所有製造業產生的排放量。這是所有人類活動中最大的單一溫室氣體來源,但我們很少提及這一點。

 

因此,我們目前面臨的是農業主宰地球這個驚人事實,無論是佔用地表 40% 的土地、消耗 70% 的水源、產生 30% 的溫室氣體排放量。光是肥料的使用,就使得逸散到全球環境中的氮、磷量倍增,導致河川、湖泊,甚至海洋的水質產生嚴重問題,這也是導致生物多樣性喪失的最大因素。因此,毫無疑問地,農業是冰河期結束後影響地球環境的最大力量,毫無疑問。它的重要性和氣候變遷不相上下,兩種危機同時發生。

 

但我們必須記住十分重要的一點:農業並非一無是處,它並非壞事,事實上,我們的生存完全仰賴它。它並非可有可無之事、並非奢侈品,而是不可或缺的需求。我們必須生產糧食、飼料、纖維,甚至生物燃料,供應世上70億人口所需。總之,未來農業需求將逐漸增加。這個需求不會消失,只會與日俱增,主要原因在於人口成長。目前地球上有70億人口,逐漸朝90億大關邁進,我們離開人世前,或許將成長為95億人口,更重要的是飲食結構的改變。隨著世界更加富裕、人口逐漸增加,我們發現飲食中的肉類消耗與日俱增,它所消耗的資源遠大於蔬菜,因此人口增加,消耗更多糧食、更多資源,當然同時導致能源危機的發生。我們必須以其它能源取代石油,最終將必須包括某種生物燃料和生質能源。因此,考量這一切因素,實在很難想像我們如何撐過這個世紀-如果無法使全球農產量倍增。

 

好,我們如何達成這個目標?如何使全球農產量倍增?

 

好,我們可以試著開墾更多土地。這是我們所做的分析,左邊是目前的農業用地,右邊是根據土質和氣候估算的潛在農業用地-假設氣候變遷對此不會產生太大影響,這並非適當的假設。我們可以開墾更多土地,但問題是,目前所剩的土地位於敏感區,其中存在龐大的生物多樣性和大量碳資源,及許多我們想保護的資源。因此,我們可藉由擴展農地生產更多糧食,但最好別這麼做,因為這對生態來說十分危險。

 

此外,我們或許希望農業碳足跡不再攀升、以更佳方式利用土地。這張圖是我們試著標出某些可在不損害環境的前提下提高農產量的地區。綠色部分代表玉米產區,顯示以玉米來說目前產量已相當高的地區,或許是以氣候和土質來說,目前世上產量最高的地區。但咖啡色和黃色部份是僅可獲得 20% 或 30% 產量的地區,你看見大部份位於非洲,甚至拉丁美洲。但令人感興趣的是東歐,它曾經是蘇聯與東歐共產國家所在地,農業發展仍十分落後。現在,這片區域需要養份和水源,需藉由有機或傳統耕作方式,或兩者混合來供應這一切。植物需要水和養份,但我們能做到這一點,我們有成功的機會。

 

但我們必須以某種兼顧未來糧食需求及環境安全的方式進行。我們必須找出一個權衡之計,使糧食生產與環境健康相輔相成。

 

現在我們面臨兩難的情況:我們可以種植糧食-如背景中的黃豆田。這個花朵型圖表顯示我們種植許多作物,但缺乏大量潔淨水源,我們沒有龐大的碳資源和生物多樣性。以環境角度來看,擁有照片中的大草原是件好事,但你無法藉此填飽肚子,沒有可吃的東西。我們必須找出兩全其美的新型耕作方式,使兩者相輔相成。

 

現在,當我談到這一點時,人們總是說,「嗯,不是已有解決之道?有機食物、當地食材、基因改造作物、新貿易補貼法案、新農業法案-」確實,我們擁有許多好方法,但沒有一個是銀彈(解決一切的方案)。事實上,我更希望解決之道是銀獵槍彈;我喜愛銀獵槍彈-結合所有方法,得到十分強大的力量,但我們必須將它們彼此結合。

 

因此我認為,我們必須做的是發明一種新型農業,同時滿足商業性農業和綠色革命需求,使有機農業、在地食材和環境保護形成最佳結合,使它們不至於彼此衝突,而是相輔相成地形成一種新型農業,我稱之為「terraculture」,或全球耕作。

 

現在,進行這樣的溝通十分困難,我們費盡心力地向大眾傳播這個重要觀點,減少爭議、促進合作。我想展示一段短片,讓你們確實瞭解我們目前所做的努力,使大家擁有相同的理念。請看影片。

 

(音樂)

 

明尼蘇達大學環境研究所:致力探索。全球人口每年增加7500萬,幾乎相當於德國總人口。目前全球人口將近70億,以這樣的速率增長,2040年全球將擁有90億人口。每個人都需要糧食,但從何而來?我們該如何餵飽逐漸增長的人口,而不對地球造成破壞?我們已知氣候變遷是個大問題,但它並非唯一的問題,我們必須面對「另一個棘手的事實」-全球農業危機。人口成長+肉類消耗+乳類消耗+能源消耗+生質能源生產=自然資源面臨的壓力。超過40% 的地表已開發為農地。全球農地超過1600萬平方公里,幾乎相當於南美洲面積。全球牧地超過3000萬平方公里,幾乎相當於非洲面積。農業佔用面積為都市和郊區總和的60倍,灌溉消耗的水源為世界之首。每年用於灌溉作物的水量相當於2800立方公里,足以每天裝滿7305棟帝國大廈。目前許多大型河川流量減少,有些早已乾涸。看看鹹海,現在已變成沙漠。科羅拉多河不再流向大海。肥料使環境中的磷和氮倍增。結果如何?造成大範圍的水污染,使湖泊及河川水質嚴重惡化。令人驚訝的是,農業是造成氣候變遷的最大因素。30%的溫室氣體由農業產生,排放量超過所有電力設施和工業,或全球飛機、火車和汽車的排放量。大部份農業排放量來自於熱帶樹林的砍伐、動物和稻田產生的甲烷、過量施肥產生的一氧化二氮。農業是改變世界的最大因素,我們的做法是影響人類生存的關鍵。我們面臨的困境是…當全球人口增加數十億時,我們需要兩倍、甚至三倍的糧食產量。我們將何去何從?我們必須進行更大規模的溝通、全球性的對話,我們必須採取真正的解決之道:鼓勵農民、精緻農業、新型作物、滴水灌溉系統、廢水回收利用、更佳的耕作方式、更睿智的飲食型態。我們需要所有人一起上桌,提倡商業性農業、環境保護及有機耕作等…我們必須同心協力,這個困境並沒有單一解決方案。我們必須攜手合作、發揮想像力、下定決心,因為我們沒有失敗的餘地。

 

如何在不破壞地球的情況下餵飽全世界?因此我們正面臨人類歷史中最大的挑戰之一:滿足90億人口的糧食需求,藉由穩定、公平、公正的方式,同時替這一代及後代子孫保護我們的地球。這將是人類歷史中最困難的挑戰之一,我們必須以正確方式進行,我們必須把握這僅有的機會。十分感謝。(掌聲)

 

以下為系統擷取之英文原文

About the Talk

A skyrocketing demand for food means that agriculture has become the largest driver of climate change, biodiversity loss and environmental destruction. ... Foley shows why we desperately need to begin "terraculture" -- farming for the whole planet. (Filmed at TEDxTC.)
 
About the Speaker
Jonathan Foley studies complex environmental systems and their affects on society. His computer models have shown the deep impact agriculture is having on our planet.
 
About the Transcript
Tonight, I want to have a conversation about this incredible global issue that's at the intersection of land use, food and environment, something we can all relate to, and what I've been calling the other inconvenient truth.
 
But first, I want to take you on a little journey. Let's first visit our planet, but at night, and from space. This is what our planet looks like from outer space at nighttime, if you were to take a satellite and travel around the planet. And the thing you would notice first, of course, is how dominant the human presence on our planet is. We see cities, we see oil fields, you can even make out fishing fleets in the sea, that we are dominating much of our planet, and mostly through the use of energy that we see here at night. But let's go back and drop it a little deeper and look during the daytime. What we see during the day is our landscapes.
 
This is part of the Amazon Basin, a place called Rondônia in the south-center part of the Brazilian Amazon. If you look really carefully in the upper right-hand corner, you're going to see a thin white line, which is a road that was built in the 1970s. If we come back to the same place in 2001, what we're going to find is that these roads spurt off more roads, and more roads after that, at the end of which is a small clearing in the rainforest where there are going to be a few cows. These cows are used for beef. We're going to eat these cows. And these cows are eaten basically in South America, in Brazil and Argentina. They're not being shipped up here. But this kind of fishbone pattern of deforestation is something we notice a lot of around the tropics, especially in this part of the world.
 
If we go a little bit further south in our little tour of the world, we can go to the Bolivian edge of the Amazon, here also in 1975, and if you look really carefully, there's a thin white line through that kind of seam, and there's a lone farmer out there in the middle of the primeval jungle. Let's come back again a few years later, here in 2003, and we'll see that that landscape actually looks a lot more like Iowa than it does like a rainforest. In fact, what you're seeing here are soybean fields. These soybeans are being shipped to Europe and to China as animal feed, especially after the mad cow disease scare about a decade ago, where we don't want to feed animals animal protein anymore, because that can transmit disease. Instead, we want to feed them more vegetable proteins. So soybeans have really exploded, showing how trade and globalization are really responsible for the connections to rainforests and the Amazon -- an incredibly strange and interconnected world that we have today.
 
Well, again and again, what we find as we look around the world in our little tour of the world is that landscape after landscape after landscape have been cleared and altered for growing food and other crops.
 
So one of the questions we've been asking is, how much of the world is used to grow food, and where is it exactly, and how can we change that into the future, and what does it mean? Well, our team has been looking at this on a global scale, using satellite data and ground-based data kind of to track farming on a global scale. And this is what we found, and it's startling. This map shows the presence of agriculture on planet Earth. The green areas are the areas we use to grow crops, like wheat or soybeans or corn or rice or whatever. That's 16 million square kilometers' worth of land. If you put it all together in one place, it'd be the size of South America. The second area, in brown, is the world's pastures and rangelands, where our animals live. That area's about 30 million square kilometers, or about an Africa's worth of land, a huge amount of land, and it's the best land, of course, is what you see. And what's left is, like, the middle of the Sahara Desert, or Siberia, or the middle of a rain forest. We're using a planet's worth of land already. If we look at this carefully, we find it's about 40 percent of the Earth's land surface is devoted to agriculture, and it's 60 times larger than all the areas we complain about, our suburban sprawl and our cities where we mostly live. Half of humanity lives in cities today, but a 60-times-larger area is used to grow food. So this is an amazing kind of result, and it really shocked us when we looked at that.
 
So we're using an enormous amount of land for agriculture, but also we're using a lot of water. This is a photograph flying into Arizona, and when you look at it, you're like, "What are they growing here?" It turns out they're growing lettuce in the middle of the desert using water sprayed on top. Now, the irony is, it's probably sold in our supermarket shelves in the Twin Cities. But what's really interesting is, this water's got to come from some place, and it comes from here, the Colorado River in North America. Well, the Colorado on a typical day in the 1950s, this is just, you know, not a flood, not a drought, kind of an average day, it looks something like this. But if we come back today, during a normal condition to the exact same location, this is what's left. The difference is mainly irrigating the desert for food, or maybe golf courses in Scottsdale, you take your pick. Well, this is a lot of water, and again, we're mining water and using it to grow food, and today, if you travel down further down the Colorado, it dries up completely and no longer flows into the ocean. We've literally consumed an entire river in North America for irrigation.
 
Well, that's not even the worst example in the world. This probably is: the Aral Sea. Now, a lot you will remember this from your geography classes. This is in the former Soviet Union in between Kazakhstan and Uzbekistan, one of the great inland seas of the world. But there's kind of a paradox here, because it looks like it's surrounded by desert. Why is this sea here? The reason it's here is because, on the right-hand side, you see two little rivers kind of coming down through the sand, feeding this basin with water. Those rivers are draining snowmelt from mountains far to the east, where snow melts, it travels down the river through the desert, and forms the great Aral Sea. Well, in the 1950s, the Soviets decided to divert that water to irrigate the desert to grow cotton, believe it or not, in Kazakhstan, to sell cotton to the international markets to bring foreign currency into the Soviet Union. They really needed the money. Well, you can imagine what happens. You turn off the water supply to the Aral Sea, what's going to happen? Here it is in 1973, 1986, 1999, 2004, and about 11 months ago. It's pretty extraordinary. Now a lot of us in the audience here live in the Midwest. Imagine that was Lake Superior. Imagine that was Lake Huron. It's an extraordinary change.
 
This is not only a change in water and where the shoreline is, this is a change in the fundamentals of the environment of this region. Let's start with this. The Soviet Union didn't really have a Sierra Club. Let's put it that way. So what you find in the bottom of the Aral Sea ain't pretty. There's a lot of toxic waste, a lot of things that were dumped there that are now becoming airborne. One of those small islands that was remote and impossible to get to was a site of Soviet biological weapons testing. You can walk there today. Weather patterns have changed. Nineteen of the unique 20 fish species found only in the Aral Sea are now wiped off the face of the Earth. This is an environmental disaster writ large.
 
But let's bring it home. This is a picture that Al Gore gave me a few years ago that he took when he was in the Soviet Union a long, long time ago, showing the fishing fleets of the Aral Sea. You see the canal they dug? They were so desperate to try to, kind of, float the boats into the remaining pools of water, but they finally had to give up because the piers and the moorings simply couldn't keep up with the retreating shoreline. I don't know about you, but I'm terrified that future archaeologists will dig this up and write stories about our time in history, and wonder, "What were you thinking?" Well, that's the future we have to look forward to.
 
We already use about 50 percent of the Earth's fresh water that's sustainable, and agriculture alone is 70 percent of that. So we use a lot of water, a lot of land for agriculture. We also use a lot of the atmosphere for agriculture. Usually when we think about the atmosphere, we think about climate change and greenhouse gases, and mostly around energy, but it turns out agriculture is one of the biggest emitters of greenhouse gases too. If you look at carbon dioxide from burning tropical rainforest, or methane coming from cows and rice, or nitrous oxide from too many fertilizers, it turns out agriculture is 30 percent of the greenhouse gases going into the atmosphere from human activity. That's more than all our transportation. It's more than all our electricity. It's more than all other manufacturing, in fact. It's the single largest emitter of greenhouse gases of any human activity in the world. And yet, we don't talk about it very much.
 
So we have this incredible presence today of agriculture dominating our planet, whether it's 40 percent of our land surface, 70 percent of the water we use, 30 percent of our greenhouse gas emissions. We've doubled the flows of nitrogen and phosphorus around the world simply by using fertilizers, causing huge problems of water quality from rivers, lakes, and even oceans, and it's also the single biggest driver of biodiversity loss. So without a doubt, agriculture is the single most powerful force unleashed on this planet since the end of the ice age. No question. And it rivals climate change in importance. And they're both happening at the same time.
 
But what's really important here to remember is that it's not all bad. It's not that agriculture's a bad thing. In fact, we completely depend on it. It's not optional. It's not a luxury. It's an absolute necessity. We have to provide food and feed and, yeah, fiber and even biofuels to something like seven billion people in the world today, and if anything, we're going to have the demands on agriculture increase into the future. It's not going to go away. It's going to get a lot bigger, mainly because of growing population. We're seven billion people today heading towards at least nine, probably nine and a half before we're done. More importantly, changing diets. As the world becomes wealthier as well as more populous, we're seeing increases in dietary consumption of meat, which take a lot more resources than a vegetarian diet does. So more people, eating more stuff, and richer stuff, and of course having an energy crisis at the same time, where we have to replace oil with other energy sources that will ultimately have to include some kinds of biofuels and bio-energy sources. So you put these together. It's really hard to see how we're going to get to the rest of the century without at least doubling global agricultural production.
 
Well, how are we going to do this? How are going to double global ag production around the world?
 
Well, we could try to farm more land. This is an analysis we've done, where on the left is where the crops are today, on the right is where they could be based on soils and climate, assuming climate change doesn't disrupt too much of this, which is not a good assumption. We could farm more land, but the problem is the remaining lands are in sensitive areas. They have a lot of biodiversity, a lot of carbon, things we want to protect. So we could grow more food by expanding farmland, but we'd better not, because it's ecologically a very, very dangerous thing to do.
 
Instead, we maybe want to freeze the footprint of agriculture and farm the lands we have better. This is work that we're doing to try to highlight places in the world where we could improve yields without harming the environment. The green areas here show where corn yields, just showing corn as an example, are already really high, probably the maximum you could find on Earth today for that climate and soil, but the brown areas and yellow areas are places where we're only getting maybe 20 or 30 percent of the yield you should be able to get. You see a lot of this in Africa, even Latin America, but interestingly, Eastern Europe, where Soviet Union and Eastern Bloc countries used to be, is still a mess agriculturally. Now, this would require nutrients and water. It's going to either be organic or conventional or some mix of the two to deliver that. Plants need water and nutrients. But we can do this, and there are opportunities to make this work.
 
But we have to do it in a way that is sensitive to meeting the food security needs of the future and the environmental security needs of the future. We have to figure out how to make this tradeoff between growing food and having a healthy environment work better.
 
Right now, it's kind of an all-or-nothing proposition. We can grow food in the background -- that's a soybean field — and in this flower diagram, it shows we grow a lot of food, but we don't have a lot clean water, we're not storing a lot of carbon, we don't have a lot of biodiversity. In the foreground, we have this prairie that's wonderful from the environmental side, but you can't eat anything. What's there to eat? We need to figure out how to bring both of those together into a new kind of agriculture that brings them all together.
 
Now, when I talk about this, people often tell me, "Well, isn't blank the answer?" -- organic food, local food, GMOs, new trade subsidies, new farm bills -- and yeah, we have a lot of good ideas here, but not any one of these is a silver bullet. In fact, what I think they are is more like silver buckshot. And I love silver buckshot. You put it together and you've got something really powerful, but we need to put them together.
 
So what we have to do, I think, is invent a new kind of agriculture that blends the best ideas of commercial agriculture and the green revolution with the best ideas of organic farming and local food and the best ideas of environmental conservation, not to have them fighting each other but to have them collaborating together to form a new kind of agriculture, something I call "terraculture," or farming for a whole planet.
 
Now, having this conversation has been really hard, and we've been trying very hard to bring these key points to people to reduce the controversy, to increase the collaboration. I want to show you a short video that does kind of show our efforts right now to bring these sides together into a single conversation. So let me show you that. (Music) ("Institute on the Environment, University of Minnesota: Driven to Discover") (Music) ("The world population is growing by 75 million people each year. That's almost the size of Germany. Today, we're nearing 7 billion people. At this rate, we'll reach 9 billion people by 2040. And we all need food. But how? How do we feed a growing world without destroying the planet? We already know climate change is a big problem. But it's not the only problem. We need to face 'the other inconvenient truth.' A global crisis in agriculture. Population growth + meat consumption + dairy consumption + energy costs + bioenergy production = stress on natural resources. More than 40% of Earth's land has been cleared for agriculture. Global croplands cover 16 million km². That's almost the size of South America. Global pastures cover 30 million km². That's the size of Africa. Agriculture uses 60 times more land than urban and suburban areas combined. Irrigation is the biggest use of water on the planet. We use 2,800 cubic kilometers of water on crops every year. That's enough to fill 7,305 Empire State Buildings every day. Today, many large rivers have reduced flows. Some dry up altogether. Look at the Aral Sea, now turned to desert. Or the Colorado River, which no longer flows to the ocean. Fertilizers have more than doubled the phosphorus and nitrogen in the environment. The consequence? Widespread water pollution and massive degradation of lakes and rivers. Surprisingly, agriculture is the biggest contributor to climate change. It generates 30% of greenhouse gas emissions. That's more than the emissions from all electricity and industry, or from all the world's planes, trains and automobiles. Most agricultural emissions come from tropical deforestation, methane from animals and rice fields, and nitrous oxide from over-fertilizing. There is nothing we do that transforms the world more than agriculture. And there's nothing we do that is more crucial to our survival. Here's the dilemma... As the world grows by several billion more people, We'll need to double, maybe even triple, global food production. So where do we go from here? We need a bigger conversation, an international dialogue. We need to invest in real solutions: incentives for farmers, precision agriculture, new crop varieties, drip irrigation, gray water recycling, better tillage practices, smarter diets. We need everyone at the table. Advocates of commercial agriculture, environmental conservation, and organic farming... must work together. There is no single solution. We need collaboration, imagination, determination, because failure is not an option. How do we feed the world without destroying it? Yeah, so we face one of the greatest grand challenges in all of human history today: the need to feed nine billion people and do so sustainably and equitably and justly, at the same time protecting our planet for this and future generations. This is going to be one of the hardest things we ever have done in human history, and we absolutely have to get it right, and we have to get it right on our first and only try. So thanks very much.

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