WWF hopes this public support will convince governments across the world to agree to take effective action to tackle climate change, when they meet at the UN Climate Summit in Copenhagen in December.
Dr Richard Dixon, director of WWF Scotland, said: "WWF's Earth Hour promises to be the biggest show of support ever for action on climate change.
"By signing up to switch their lights off, millions of people will be showing world leaders that they care about tackling climate change.
"This is a simple way for people to show their support for strong action on climate change."
What does WWF stand for?WWF originally stood for "World Wildlife Fund". However, in 1986, WWF had come to realize that its name no longer reflected the scope of its activities, and changed its name to "World Wide Fund For Nature". The United States and Canada, however, retained the old name.
The resulting confusion caused by the name change in 1986, together with its translation into more than 15 languages, led the WWF Network in 2001 to agree on using the original acronym as its one, global name - the acronym that it had always been known by since its inception way back in 1961: "WWF".
What is WWF's mission?
WWF’s mission is to stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature, by: conserving the world’s biological diversityensuring that the use of renewable natural resources is sustainablepromoting the reduction of pollution and wasteful consumption.
In pictures: Earth Hour
Skyline of Sydney, Australia
More than 3,400 cities worldwide are taking part in Earth Hour, turning off their lights for one hour at 2030 local time in protest against climate change.
New Zealand parliament building, Wellington
New Zealand was one of the first countries to take part, with government buildings switching off all but the most essential lighting.Concert in Auckland Civic Square, New Zealand - photo Earth Hour
In Auckland, the country's biggest city, revelers turned the event into a celebration with a candlelit concert.Candles in Fiji - Photo Earth Hour
Sydney's Luna Park
Melbourne Skyline - Photo Earth Hour
Large parts of Sydney, Australia, home to the first Earth Hour two years ago, went dark. Campaigners aim to create a huge wave of public pressure to force a new climate change treaty. Melbourne was one of hundreds of Australian municipalities taking part.
Bird's Nest stadium, Beijing - Photo Earth Hour
The normally glittering Bird's Nest stadium in Beijing looked distinctly grey.Bank of China, HSBC building and others in Hong Kong
Hong Kong's financial district was plunged into near darkness.Parliament lit as usual (left) and an unlit Parliament during Earth Hour
And in London, the Houses of Parliament, as well as the London Eye, Canary Wharf, the Gherkin and the BT Tower, switched their lights off.
An Indonesian family sits near candles as lights are turned off during a candlelight vigil marking Earth Hour at the main business district in Jakarta, Indonesia.
Understanding Age Gap Relationships
Interestingly, a study on age gap relationships indicated that cases in which the wife was older than the husband showed a higher than usual proportion of good adjustments, as did those in which the husband was eight or more years older. Yet these same marriages showed also the highest proportion of poor adjustments.
It was found that the happiest group of husbands had wives twelve or more years younger, but that the happiest wives were from four to ten years older than their husbands. Yet the happiest couples were those in which the husband was from three to five years older. So you figure it out. Here are some helpful principles:
1. If the man is about the same age as, or somewhat older than the girl, there will be no special problem of age suitability.
2. If the girl is slightly older there will be no special problem unless one or the other feels sensitive about it. The only question then will be, "How do they feel about it?"
3. As people grow older, age differences become less important. Other things being equal, there will be less difference between a woman of fifty and a man of seventy, than between a girl of twenty and a man of forty.
4. When one is relatively young and the other as much as twelve years older, the couple should carefully review the following problems:
In these age gap relationships, there may be real differences in their interest in physical activities. If the man is the elder, this may not be too important. A man of thirty-five may play as good a game of golf or even tennis, and swim as well as a girl of twenty.
In fact their age gap may actually make them more evenly matched. A greater age gap relationship problem will be the stage in which their interests happen to be.
Younger people often want to gad about at dances, parties, night clubs, and similar activities. When people become older such activities are far less attractive and may, if indulged in too much, become boring.
If the male is considerably older and he and his wife do what he wants, she may miss out on a phase of her experience which, rightly or wrongly, she may always regret. If they do what she enjoys most, he is being dragged through the same experiences twice, perhaps after he is eager to go on to something else.
A compromise may work out. On the other hand, it may result in a type of social life which is satisfactory to neither of them. A deeper phase of the same problem concerns one's attitude toward life. To those of less experience the problems of age gap relationships seem much simpler than they actually are.
Young people are quite likely to feel that the older generation must be knaves or fools, or they would long since have abolished war, poverty, industrial strife and mosquitoes.
Older people,on the other hand, often find the enthusiasms of youth amusing. They may tolerate them in their children, but do not want them in a spouse. If the age gap is so great that the wife regards her husband as an old fogy, and the husband thinks of his wife as a simple child who spends too much effort and time in things that do not matter, the situation is not favorable to a successful marriage.
Yet the fact that age gap relationships are risky does not necessarily mean that it should not be attempted. One young lady of twenty-five who was marrying a man twice her age strongly stated that she would rather marry a first-class man of fifty than a third-rate man of thirty.
There could be other advantages to such a union. The girl who marries an older man has a better chance of knowing what she is getting. In any case, the most important consideration is not age, but maturity.
Younger people who are more mature than most of their contemporaries may actually find an older mate to be more congenial. Yet as in any age gap relationships, the preference for a much older mate should be scrutinized with great care.
The danger is that the older person is psychologically a substitute parent, rather than a mate.
