今天，8月20日，是今年的“地球生态超载日”，也就是说，我们已经用光了这一年地球能够提供给我们的各类自然资源，人类在余下几个月使用的资源都是在透支下一年的“生态预算”。提出这一概念的全球生态足迹网络表示，目前，人类需要1.5个地球提供的资源才能存活发展；而到本世纪中叶，大概要两个地球才能满足人类的资源需求。该机构发布的报告称，中国因人口总量而成为全球生态足迹总量最大的国家，但是其他国家的人均资源需求量却比中国高。报告指出，如果人人都像美国人那样生活的话，需要有四个地球才能满足我们的资源需求。1961年，人类存活发展只需要三分之二的地球生态资源；到了上世纪70年代，碳排放以及能源消耗增加开始让地球资源“入不敷出”。
“地球生态超载日”的概念由全球生态足迹网络及英国智库“新经济基金会”提出，其理论基础是“生态足迹分析”法，通过对比人类对自然资源和生态服务的需求（生态足迹）与地球生态系统每年的可再生供给量和吸收废弃物的能力（生态承载力），来测算人类发展的可持续性。
Humans have used up the natural resources the Earth can provide for the year and are now in 'overdraft', campaigners have warned.
The world has reached 'earth overshoot day' today, August 20, the point in the year that humans have exhausted supplies such land, trees and fish and outstripped the planet's annual capacity to absorb waste products including carbon dioxide.
For the rest of the year, the world is in ecological debt, with fish stocks and forests being depleted, land degraded and carbon dioxide building up in the atmosphere, the Global Footprint Network said.
Earth overshoot day is calculated by comparing the demands made by humans on global resources - our 'ecological footprint' - with the planet's ability to replenish resources and absorb waste.
This year, in less than nine months we have used as much of nature as the Earth can regenerate in a year. Earth overshoot day has fallen a couple of days earlier than it did last year.
The Global Footprint Network said that in 1961, humanity only used around two-thirds of the available natural resources on Earth, but by the 1970s increased carbon emissions and consumption began to outstrip what the planet could provide.
Humans now need the equivalent of 1.5 planets to sustain us, and by mid century it will have risen to two planets, the campaigners said.
China has the biggest total ecological footprint, because of its large population, but other countries have much higher demands on resources per person. If everyone were to live like U.S. residents we would need four planets to supply demand, the report said.
Four-fifths of the world's population live in countries that use more than their own natural systems can provide. In this country, we would need the equivalent of three and a half UKs to sustain current consumption levels.
The world can no longer sustain the widening budget gap between what nature is able to provide and how much our infrastructure, economies and lifestyles require, they said.
Alessandro Galli, Global Footprint Network regional director, said: 'Everyday life in many Mediterranean countries is showing us what it means to live beyond financial limits.
'Ecological and financial deficits are two sides of the same coin. Over the long run, nations cannot deal with one deficit without addressing the other.'
Andrew Simms, climate economist at Global Witness, who came up with the concept of earth overshoot day at UK think tank the New Economics Foundation, said: 'The Government consistently tells us that we must buckle down and live within our financial means, but seems intent on pushing us to break our environmental budget.
'The maths is simple - the UK consumes and produces waste at a rate three and a half times greater than we can sustain, and today humanity has already exhausted what the planet's ecosystems can provide in a year.
'We're in the red and gambling with ecological bankruptcy, as the fracking debate shows. If it chose to, the Government can always print more money, but it can't print more planet. Ecological overshoot should lead the political agenda.'