古代文明早就對地球造成破壞
隨著氣候變遷、全球暖化、再生能源等問題成為重要的國家議題，我們很容易就會認為這些課題僅限於當代社會。不過發表在《科學》的一項大規模合作計畫顯示，早在10000萬年前全球各地的古代人就已經開始改變並影響他們所處的環境。
「經由這份從眾多來源統籌而成的數據，我們可以看出至少在3000年前土地利用就已經對全世界的環境造成衝擊。」美國菲爾德自然史博物館的人類學研究員Gary Feinman如此表示。他也是這篇研究的250位作者的其中之一。「這也意謂把人類對環境造成的衝擊視為一種新興現象，其實是太過強調近代歷史而得出的概念。」
Feinman表示如果想了解我們當今面臨的氣候危機，就需要先了解人類自古以來如何改變自身所處的環境。
由美國賓州大學的Lucas Stephens主持的這項研究隸屬於另一項更大型的計畫「ArchaeoGLOBE」，這項網路上進行的調查彙整了各個區域的專家得到的資訊，以探討全球146個不同地點的土地利用方式如何演變。這些土地利用方式從狩獵採集、農耕到放養動物皆包括在內。結果顯示古代人實行的土地利用方式中，有許多跟眾人以為的「船過水無痕」相差甚遠。
Feinman表示：「大概在12000年前，人類主要以採集狩獵維生，代表他們跟環境的互動程度一般而言不如農夫跟環境的那般密切。而我們發現到了3000年前，世上許多地方人類進行的農業活動侵略性都十分地強。」
這段時期人們開始砍伐森林以種植糧食，同時馴化動植物，使它們必須仰賴人類才能生存。此外，早期牧人清理土地與選擇性育種的時候，也改變了他們的周遭環境。雖然這些變化例子進行的步調並不一致，但它們的分布範圍相當廣泛，而能夠讓我們洞悉人類和地球以及自然資源的關係是如何漸漸惡化。
「我們發現環境受到衝擊的軌跡是越來越快。」菲爾德自然史博物館的人類學副研究員暨主任Ryan Williams表示。他也是此研究的共同作者之一。「在看到目前環境以更為急遽的速率變化的同時，我們也發現人類對環境的影響在數千年前就已經有跡可循。」
不過這項研究的結果比表面上看起來更加樂觀。既然研究人員知道環境是在什麼時候開始受到衝擊，他們就能運用研究數據來探討古代文明是用什麼方法來減輕砍伐森林、水源減少等諸多活動帶來的副作用。
這項研究除了指出大多數人以為是近代才有的現象其實歷史悠久，也是第一次以如此大的規模來進行這類研究。利用線上資源並組織專業人員使得這項計畫可以涵蓋全世界。結果顯示我們經常忽略的地區其實相當重要。
Williams表示：「我們需要投注資源在那些還沒有受到大量研究的區域。如果我們鼓勵這些地方的研究人員並為他們創造機會，你可以想像下一個這樣的研究可以得到多麼豐碩的成果。」
長久以來，戰爭、環境、交通和殖民因素使得研究人員難以互相合作，並且跟世上某些地區的人們分享他們的成果，造成考古學家時至今日仍在招攬這些區域的專家並拓展合作網路。
「雖然我認為研究結果確實支持了許多考古學家的猜測，但這項研究真正吸引我的地方不是成果有多少。」Feinman表示，「我認為這項研究最創新的地方是研究整體的設計：彙整250位學術人員擁有的資訊，並確保全世界都涵蓋其中。這是一項非常了不起的成就。」
雖然目前氣候變遷及環境破壞的速度與規模都遠遠超出世上任何一處發生過的，但Feinman指出這項研究可以讓我們從歷史脈絡來看待目前的問題。
「當今科學界十分強調過往與現在有多麼不同。我認為這項研究從另外一個角度平衡了這項觀點；確實，結果顯示出土地利用方式在近代變化得更加快速，但人類這麼做的歷史其實十分久遠，從3000年前就開始可以看到土地利用的變化模式。」Feinman表示，「這表示我們當今面臨的問題有著相當悠久的淵源，不是用單純的方法就能解決它們，而且我們絕對不能置之不理。」
Ancient civilizations were already messing up the planet
As issues like climate change, global warming, and renewable
energy dominate the national conversation, it's easy to assume these topics are
exclusive to the modern world. But a huge collaborative study in Science reveals
that early humans across the entire globe were changing and impacting their
environments as far back as 10,000 years ago.
"Through this
crowdsourced data, we can see that there was global environmental impact by
land use at least 3,000 years ago," says Gary Feinman, MacArthur Curator
of Anthropology at the Field Museum and one of the study's 250 authors.
"And that means that the idea of seeing human impact on the environment as
a newer phenomenon is too focused on the recent past."
Feinman says that to
understand our current climate crisis, we need to understand the history of
humans altering their environments.
The study, led by Lucas
Stephens of the University of Pennsylvania, is a part of a larger project
called ArchaeoGLOBE, where online surveys are used to gather information from
regional experts on how land use has changed over time in 146 different areas around
the world. Land use can be anything from hunting and gathering to farming to
grazing animals. And as it turns out, many of the ways ancient people used the
land weren't as "leave-no-trace" as many have imagined.
"About 12,000 years
ago, humans were mainly foraging, meaning they didn't interact with their
environments as intensively as farmers generally do," says Feinman.
"And now we see that 3,000 years ago, we have people doing really invasive
farming in many parts of the globe."
Humans in these time
periods began clearing out forests to plant food and domesticating plants and
animals to make them dependent on human interaction. Early herders also changed
their surroundings through land clearance and selective breeding. While these
changes were at varying paces, the examples are now known to be widespread and
can provide insight on how we came to degrade our relationship with the Earth
and its natural resources.
"We saw an accelerated
trajectory of environmental impact," says Ryan Williams, associate curator
and head of anthropology at the Field Museum and co-author of the study.
"While the rate at which the environment is currently changing is much
more drastic, we see the effects that human impacts had on the Earth thousands
of years ago."
The results, however, are
more optimistic than they seem. Now that researchers know the beginnings of
environmental impact, they can use this data to study what solutions ancient
civilizations used to mitigate the negative effects of deforestation, water
scarcity, and more.
In addition to pointing out
the history behind what most assume is a recent phenomenon, the study is one of
the first of its kind to operate on such a large scale. Use of online resources
and professional connections helped the project span across the world. The
emphasis now, however, is on the parts we often miss.
"We need to invest in
these regions that haven't been as intensively studied," says Williams.
"If we incentivize and create opportunities for researchers there then you
can just imagine what the results of the next study like this could be."
For a long time, war,
environment, transportation and colonization prevented researchers from being
able to work together and share their findings about certain parts of the
world. As a result, today's archaeologists are still adding to and growing the
network of expertise in these regions.
"What really got me
here was not so much the results, although I think that the results provide a
foundation to support what many archeologists suspected," says Feinman.
"But I think the most innovative aspect of this was the whole research
design. To gather information from 250 scholars and to make sure that the whole
world was covered, that's really something."
While today's climate
change and environmental destruction are happening more quickly and on a far
larger scale than the world has ever seen, Feinman notes that this study helps
provide a historical context to today's problems.
"There's such a focus
on how the present is different from the past in contemporary science. I think
this study provides a check, a counter-weight to that, by showing that yes,
there have been more accelerated changes in land use recently, but humans have
been doing this for a long time. And the patterns start 3,000 years ago,"
says Feinman. "It shows that the problems we face today are very
deep-rooted, and they are going to take more than simple solutions to solve.
They cannot be ignored."
原始論文：Lucas Stephens
et al. Archaeological assessment reveals Earth’s early transformation
through land use. Science, 2019 DOI: 10.1126/science.aax1192
引用自：Field Museum. "Ancient civilizations were
already messing up the planet."
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