What worries Bill Gates most？ Thebooming population of Africa looms over his foundations latest global survey. By the end of this century there will be 4 billion more people on Earth-and 3 billion of these extra souls will be born in Africa. The challenge， he says， is that“Africa must almost quadruple its agricultural productivity to feed itself. Thats very daunting.

The philanthropist is torn between sending out a message of hope and a message of fear when I meet him at his foundations spacious campus in the heart of his hometown， Seattle.

He is reaching for what works best torevive the Wests faltering conscience in theface of“America first”nationalism and rising pull-up-the-draw bridge populismin Europe. The spirit of generosity is under assault as government aid budgets come under constant sniper fire from right-wing politicians and their media.

Half of the Bill & Melinda Gates Foundation spending goes to Africa. The funds put into the foundation by themselves and fellow philanthropist Warren Buffett now amount to more than than $50bn. Until last year Gates， the Microsoft founder， was the worlds richest man. He has now been over taken by Amazons Jeff Bezos.

The foundations report bursts with remarkable data-too few people know aboutthe galloping progress of human kind. Take India， where only 18 years ago almost one in five children were not enrolled in primary school-now， 97% attend classes. Look at the indicatorson the reports global score card for the UNssustainable development goals for 2030， and most things are improving almost everywhere. But there is a marked variation in the future trajectory： progress depends on the level of future investment.

Today， the West takes some persuading that things are getting better， especially in Europe where countries like Britain have suffered a decade of falling real living standards and eye-watering austerity. The upbeat message of Gates-as well as those in his late friend Hans Roslings book Factfulness， and Steven Pinkers Enlightenment Now-telling us most of the world is on an unprecedented up swing， jars with our reality. Yet it is so： the world has never seen such a rapid rise in prosperity among most of the poor.

Eager to encourage Western countries to keep giving aid， Gates is well aware that Britain-as else where-suffers frequent politicalattacks on its aid budget. The UK， Sweden and Norway are among the few reaching the UNaid spending target of 0.7% of gross nationalin come， and all feel the cold blast of an anti-foreigner political grudge. “If you are saving lives for a very small amount of money， people should feel good about that，” Gates says emphatically， protesting at current cynicism about internationa laid organisations. Look what can be done， he keeps saying， pointing as an example to the brilliant education system in Vietnam， a poor country whose results outstrip far richer ones.

If Britain needs encouragement， he says， “the data about the impact has been amazing. The UK has been very generous to the vaccine fund， for two vaccins—one for pneumonia， one for diarrhoea.” These sicknesses are now preventable“at extremely low cost to all the children of the world. The UK led that effort and saved over 10 million lives”. Do people across the UK know that？ He admits a failure to spread the good news. “We re being challenged to explain.” Everyone should know this message of hope. “Were talking about up lifting the human condition in a fairly dramatic way.”

But if hope doesnt beat the new nativism infecting the Western world， then fear is Gates ammunition of last resort. lgnore Africa at your peril. “The stability of Africa makes a huge difference to the entire world.” Here come the threats：“A pandemic like Ebola can spread very fast，” he warns， and many others spread even faster if there are no local health services to contain them.

Migration is the other threat to touch Europes politics. Syria was a small country， he reminds us， yet its civil war exodus has“challenged the asylum system”. But watch out because“Africa is another order of magnitude.The huge African youth boom is a strong the mein the report， where in a world of ageing and shrinking populations， Africas demographicbulge could be an asset or a threat. So it would be wise“to make their lives attractive”not just out of“pure human caring”. Invest in Africas young， their human capital， health andeducation， support more productive agriculture， protect subsistence farmers against climate change and see how self-interest blends with good works.

Africa， he always stresses， is not one country. Of its 54 nations， many are leaping ahead， Ghana， Bot swana and Rwanda among them. Those causing concern are the Democratic Republic of the Congo and Nigeria.

On his recent visit he warned Nigerians against the countrys growing inequality， where oil wealth for a few is leaving millions behind. The found ation has spent $1bn so far on Nigeria. He says，“Their health system is worse than poorer countries， their agricultural advice largely broken down.” Government resourcesare low because“their level of taxation is one of the lowest in the world”.

比爾·蓋茨最擔(dān)心的是什么？在他的基金會最新的全球調(diào)查中，非洲人口的迅速增長成為一個隱憂。到本世紀(jì)末，地球上的人口將增加40億，其中30億人將在非洲出生。他表示，挑戰(zhàn)在于“非洲必須將農(nóng)業(yè)產(chǎn)能提高近四倍，才能養(yǎng)活自己。這是非常艱巨的?！?/p>

當(dāng)我在他的基金會，位于他家鄉(xiāng)西雅圖中心地帶的寬敞校園里見到這位慈善家時，他既表達(dá)了希望，又表達(dá)了恐懼。

面對“美國優(yōu)先”的民族主義和歐洲日益高漲的民粹主義，他正在尋找最有效的方法，以重振西方搖搖欲墜的良知。由于政府援助預(yù)算不斷受到右翼政客和其媒體的冷嘲熱諷，慷慨的精神受到了攻擊。

比爾及梅林達(dá)·蓋茨基金會一半的開支都花在了非洲。這個基金會現(xiàn)有資金已經(jīng)超過500億美元了，主要來自蓋茨夫婦和同伴慈善家沃倫·巴菲特。直到去年，微軟創(chuàng)始人蓋茨還是世界首富。如今，他已被亞馬遜的杰夫·貝索斯超越。

該基金會的報告充滿驚人的數(shù)據(jù)——很少有人知道人類的飛速進(jìn)步。以印度為例，僅在18年前，該國近五分之一的孩子沒有小學(xué)上，而現(xiàn)在97%的孩子上了小學(xué)。看看報告中聯(lián)合國2030年可持續(xù)發(fā)展目標(biāo)的全球記分卡上的指標(biāo)，幾乎所有地方的情況都在改善。但未來的軌跡有一個明顯的變化：進(jìn)展取決于未來的投資水平。

如今，西方國家需要說服一些人相信情況正在好轉(zhuǎn)，尤其在歐洲像英國這樣的國家，10年來實際生活水平不斷下降和緊縮令人難以忍受。蓋茨的樂觀信息一以及他已故的朋友漢斯·羅斯林的《事實》——書和史蒂芬·平克的《當(dāng)下的啟蒙》——告訴我們，世界上大部分地區(qū)正處于前所未有的繁榮時期，與我們的現(xiàn)實不符。但事實的確如此：從未見過大多數(shù)窮人的財富增長得如此迅速。

蓋茨急于鼓勵西方國家繼續(xù)提供援助。他很清楚，英國和其他國家一樣，在援助預(yù)算上經(jīng)常遭受政治攻擊。英國、瑞典和挪威是少數(shù)幾個實現(xiàn)了占國民總收入0. 7%的聯(lián)合國援助支出目標(biāo)的國家，它們都感受到了反外國人政治仇恨的寒流。蓋茨強調(diào)說：“如果你是在用非常少的錢拯救生命，人們應(yīng)該對此感到高興?！彼棺h目前對國際援助組織的冷嘲熱諷?？纯茨茏鲂┦裁?，他一直這樣說，并以越南優(yōu)秀的教育體系為例。越南是一個貧窮的國家，其教育成果卻超過了比它富裕得多的國家。

如果英國需要鼓勵，他說，“關(guān)于影響的數(shù)據(jù)是驚人的。英國非?？犊叵蛞呙缁鹛峁┝藘煞N疫苗，一種用于肺炎，另一種用于腹瀉?！爆F(xiàn)在這些疾病對于全世界的孩子來說都是可以預(yù)防的，而且代價很低。英國在這一件事上起了主要作用，拯球了1000多萬條生命。全英國的人都知道嗎？他承認(rèn)這一好消息并沒有成功傳播。“我們正面臨解釋的挑戰(zhàn)?！泵總€人都應(yīng)該知道這個充滿希望的信息?！拔覀冋f的是以一種相當(dāng)戲劇性的方式改善人類的狀況。”

但是，如果（慈善的）希望不能擊敗影響西方世界的新本土主義，那么恐懼就是蓋茨最后的武器。忽視非洲，后果自負(fù)。“非洲的穩(wěn)定會讓整個世界變得不一樣。他警告說，威脅來了：“像埃博拉這樣的流行疾病傳播得非?？??！比绻麤]有當(dāng)?shù)氐尼t(yī)療服務(wù)機構(gòu)控制，其他許多疾病傳播的速度甚至更快。

移民是影響歐洲政治的另一個威脅。他提醒我們，敘利亞是一個小國，但內(nèi)戰(zhàn)期間的大批難民“挑戰(zhàn)了庇護(hù)制度”。但要小心，因為“非洲是另一個大威脅”。在人口老齡化和人口萎縮的世界里，非洲的人口膨脹可能是一種資產(chǎn)，也可能是一種威脅。因此，明智的做法是“讓他們的生活更有吸引力”，而不僅僅是“純粹的人文關(guān)懷”。投資于非洲的年輕人，他們的人力資本，健康和教育，支持更多產(chǎn)的農(nóng)業(yè)，保護(hù)自給自足的農(nóng)民免受氣候變化的影響，看看自身利益如何與良好的工作相結(jié)合。

他總是強調(diào)，非洲不是一個國家。在它的54個國家中，許多國家正在躍躍欲試，其中包括加納、博茨瓦納和盧旺達(dá)。引起關(guān)注的是剛果民主共和國和尼日利亞。在他最近的訪問中，他警告尼日利亞人注意該國日益加劇的不平等。在那里，少數(shù)人的石油財富正將數(shù)百萬人拋在身后。該基金會迄今已在尼日利亞投入10億美元。他表示：“他們的醫(yī)療體系比貧窮國家更糟糕，他們的農(nóng)業(yè)建議在很大程度上遭到了破壞。政府資源低是因為“他們的稅收水平是全球最低之一”。