希腊神话中大地女神Gaia，又称地母。是第二个出生的神，属于古老的神一类。Gaia生于混沌（chaos），又生天空之父（Cronus），后与天父生下很多孩子，如泰坦巨人（Titan）等。

盖亚假说（Gaia hypothesis）是由英国大气学家拉伍洛克（James E.lovelock）在20世纪60年代末提出的。后来经过他和美国生物学家马古利斯（ Lynn margulis）共同推进，逐渐受到西方科学界的重视，并对人们的地球观产生着越来越大的影响。同时盖亚假说也成为西方环境保护运动和绿党行动的一个重要的理论基础。

盖亚假说至少包含5 个层次的含义：一是认为地球上的各种生物有效地调节着大气的温度和化学构成；二是地球上的各种生物体影响生物环境，而环境又反过来影响达尔文的生物进化过程，两者共同进化；三是各种生物与自然界之间主要由负反馈环连接，从而保持地球生态的稳定状态；四是认为大气能保持在稳定状态不仅取决于生物圈，而且在一定意义上为了生物圈；五是认为各种生物调节其物质环境，以便创造各类生物优化的生存条件。前两层被称为弱盖亚学说，后三层为强盖亚学说。

盖亚假说的核心思想是认为地球是一个生命有机体。James Lovelock说过：“地球是活着的！”，而且地球本身就是一个巨大的有机体，具有自我调节的能力，为了这个有机体的健康，假如她的内在出现了一些对她有害的因素，“盖亚”本身具有一种反制回馈的机能，能够将那些有害的因素去除掉。

英国科学博物馆最近给拉伍洛克搞了一次个人科学家展览。这对一个在世科学家来说，是非常罕见的活动。拉伍洛克是英国著名的科学家，他在医学、环境科学和行星学有很深造诣。1919年出生的拉伍洛克最有名的是提出了盖亚假说。盖亚假说核心观点是把地球作为一个自我调节系统，类似有生命的有机体。这个观点在上世纪70年代提出时引起很大争议，但是环境和地球科学家现在对这一假说的主要原理已经非常认可。

拉伍洛克在他2006年出版的新书The Revenge of Gaia中预言今后10年内环境改变会引起灾难性后果，只有少数人能幸免于难“only a handful of theteeming billions now alive will survive”。上周《自然》也专门有一篇介绍拉伍洛克生平的文章。

以下是记者对拉伍洛克的采访：

Is climate change going to be lessextreme than you previously thought?

TheRevenge of Gaia was over the top, but we were all so taken in by the perfectcorrelation between temperature and CO2 in the ice-core analyses [from theice-sheets of Greenland and Antarctica, studied since the 1980s]. You coulddraw a straight line relating temperature and CO2, and it was such a temptationfor everyone to say, “Well, with CO2 rising we can say in such and such a yearit will be this hot.” It was a mistake we all made.

Weshouldn’t have forgotten that the system has a lot of inertia and we’re notgoing to shift it very quickly. The thing we’ve all forgotten is the heatstorage of the ocean — it’s a thousand times greater than the atmosphere andthe surface. You can’t change that very rapidly.

Butbeing an independent scientist, it is much easier to say you made a mistakethan if you are a government department or an employee or anything like that.

So what will the next 100years look like?

That’s impossible to answer. All I can sayis that it will be nowhere as near as bad as the worst-case scenario.

Are you still pessimistic about theprospect of finding a political solution to climate change?

Absolutely.

In your latest book you advocate not tryingto halt climate change but exercising what you call a sustainable retreat. Whyis that?

I think it is the better approach. To rushahead and advance is very much the Napoleonic approach to battle. It is farbetter to think about how we can protect ourselves. If we’re going to do anygood, we should be making more effort to keep our own home a suitable place tolive in for the future than desperately trying to save somewhere remote. Thisis particularly true of Britain. We nearly died in the Second World War forlack of food. Our agricultural production hasn’t gone up enough to supplytoday’s population with what we would need. This is something we should belooking at carefully, not just applying guesswork and hoping for the best.

Will nuclear energy be part of the future,despite the Fukushima nuclear disaster in Japan?

The business with Fukushima is a joke.Well, it’s not a joke, it is very serious — how could we have been misled byanything like that? Twenty-six thousand people were killed by the magnitude-9earthquake and tsunami [that caused the nuclear meltdown], and how many areknown to have been killed by the nuclear accident? None.

[On the Chernobyl nuclear disaster,Lovelock writes in A Rough Ride to the Future: “The most amazing lieswere told, still are told and widely believed… Despite at least threeinvestigations by reputable physicians, there has been no measurable increasein deaths across Eastern Europe.”]

A lot of investment in green technology hasbeen a giant scam, if well intentioned.

Do you feel vindicated about the way manyof the ideas in the Gaia hypothesis have now been accepted by Earth-systemsscientists?

I think it is a matter of scientificpolitics. In practice, most of the senior biologists I encountered in latertimes had no problem with the notion at all. But they fought bitterly at first.It was very funny to talk with John Maynard Smith, Bill Hamilton and Robert May[eminent evolutionary and population biologists], and to discover that none ofthem had read any of my books or papers — they were judging the idea by whattheir students told them.

Was some of that criticism helpful?

In the early stages it wasn’t. And on thegeology side it was something quite different — the tendency of some geologiststo keep their heads in the sediments is very strong, and they won’t shift it.I’m very intrigued by the latest attempt to resuscitate the idea that all ofclimate regulation is done by rock weathering. The geologists keep on ignoringthe bacteria.

A 1984 rejection letter from Nature ofyour paper outlining the Gaia hypothesis is displayed in the exhibition. Whatdo you think of peer review — is it necessary?

Well, as far as I’m concerned, I don’t haveany peer review. But I don’t think it is practical to get rid of it. Forrun-of-the-mill papers, say if somebody comes up with a really neat method foranalysing some component of urine or that kind of thing, it is important tokeep it. But not on larger topics.

Nature doi:10.1038/nature.2014.15017

http://www.jameslovelock.org/page0.html