For the past century, the world's great powers have pursued better living conditions, fought against each other and worked frantically to develop technologies useful for fighting wars, all in total disregard of the environment.

If this continues, the Earth's environment will become so contaminated that sooner or later the death knell will sound for the human race.

Scientists estimate that the Earth came into being 4.5 billion years ago, and that humans first appeared 5 million to 6 million years ago. Since its appearance on Earth, the human race has done nothing but damage other forms of life in pursuit of its own happiness.

Such selfish deeds could lead to disaster in the form of counterattacks from living organisms or drastic environmental changes (remember the glacial epoch?), culminating in the extinction of human kind.

This may not come in the foreseeable future, but if the egocentric attitude of human beings continues, damage to the environment will certainly become far more serious than what is now being discussed regarding global warming, and the entire Earth will be destroyed.

This is an issue that political leaders throughout the world must ponder. A leader who thinks he doesn't have to worry about the extinction of the human race or the destruction of the Earth because such events will not transpire in his lifetime is not fit for his position.

Even though a calamity of such magnitude may not come anytime soon, scientific progress has made it easier to foresee the future. That is why the 1997 Kyoto conference addressed the problem of global warming.

The conferees adopted the Kyoto Protocol, which identified six toxic gases and set targets for reducing the emission of such gases.

Members of the European Union were called upon to reduce their emissions by 8 percent from 1990 levels, the United States by 7 percent, Japan, Canada, Hungary and Poland by 6 percent and Croatia by 5 percent, while no reduction targets were set for New Zealand, Russia, Ukraine, Norway, Australia and Iceland, which had already attained low emissions levels.

The signatories to the Kyoto Protocol were to ratify the instrument by around mid-2002, begin to implement its provisions in 2008 and meet their targets by the end of 2012.

It should be recalled that the Kyoto conference was the culmination of a decade of efforts to address global warming. Therefore, the signatories to the protocol are obligated to abide by and implement what was agreed upon.

A major stumbling block developed when U.S. President George W. Bush announced America's withdrawal from the Kyoto Protocol on grounds that it would impede the U.S. economy.

Prime Minister Junichiro Koizumi called on Washington to reconsider its decision and ratify the treaty, pointing out that without the participation of the U.S., the Kyoto Protocol would be meaningless.

I think Koizumi did the right thing. Even though Bush says the Kyoto Protocol would be detrimental to the American economy, there must be ways to overcome this problem.

I agree the Kyoto Protocol is not perfect as major powers like China and India are excluded. For the sake of their own economic future, those countries should become parties to the arrangement and set their own targets for reducing emissions of greenhouse gases. A U.S. ratification of the protocol would open the way for China and India to get involved.

It is impossible to solve all the pollution problems and create a clean Earth in the near future, but as individuals responsible for the future of the Earth and of mankind, the world's political leaders should work to make the Earth a pollution-free planet.

What is important is not the technical feasibility of attaining the goal but rather the philosophical attitude of the leaders. The late British historian Arnold Toynbee once said that unless something drastic is done, the entire human race will perish, and that only religions and high moral standards can save mankind and the Earth.

Toynbee also said that humans must live together with everything on the Earth, not just flora and fauna but also with forests, rivers, seas and all natural things.