地球生態超載日：我們一直在透支

今天，8月20日，是今年的“地球生態超載日”，也就是說，我們已經用光了這一年地球能夠提供給我們的各類自然資源，人類在餘下幾個月使用的資源都是在透支下一年的“生態預算”。提出這一概念的全球生態足跡網絡表示，目前，人類需要1.5個地球提供的資源才能存活發展；而到本世紀中葉，大概要兩個地球才能滿足人類的資源需求。該機構發佈的報告稱，中國因人口總量而成爲全球生態足跡總量最大的國家，但是其他國家的人均資源需求量卻比中國高。報告指出，如果人人都像美國人那樣生活的話，需要有四個地球才能滿足我們的資源需求。1961年，人類存活發展只需要三分之二的地球生態資源；到了上世紀70年代，碳排放以及能源消耗增加開始讓地球資源“入不敷出”。

“地球生態超載日”的概念由全球生態足跡網絡及英國智庫“新經濟基金會”提出，其理論基礎是“生態足跡分析”法，通過對比人類對自然資源和生態服務的需求（生態足跡）與地球生態系統每年的可再生供給量和吸收廢棄物的能力（生態承載力），來測算人類發展的可持續性。

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.'