Make a list of all the environmental and social problems that today afflict us and our poor battered planet. – not just the extinction of species and animals and plants, that fifty years ago was the first signs of impending global disaster, but traffic congestion, oil prices, pressure on the health service, the growth of mega-cities, migration patterns, immigration policies, unemployment, the loss of arable land, desertification, famine, increasingly violent weather, the acidification of the oceans, the collapse of fish stocks, rising sea temperatures, the loss of rain forest. The list goes on and on. But they all share an underlying cause. Every one of these global problems, environmental as well as social becomes more difficult – and ultimately impossible - to solve with ever more people.

There are some who look on our global problems here on Earth — at our vast national antagonisms, our nuclear arsenals, our growing populations, the disparity between the poor and the affluent, shortages of food and resources, and our inadvertent alterations of the natural environment — and conclude that we live in a system that has suddenly become unstable, a system that is destined soon to collapse. There are others who believe that our problems are soluble, that humanity is still in its childhood, that one day soon we will grow up.

We also have a world facing multiple crises: a wave of brutal armed conflict,the negative effect of climate change , increasing polarized societies , inequalities discrimination and rising cost of living.

I used to think the top global environmental problems were biodiversity loss, ecosystem collapse and climate change. I thought that with 30 years of good science we could address these problems. But I was wrong. The top environmental problems are selfishness, greed and apathy, and to deal with these we need a spiritual and cultural transformation, and we scientists don't know how to do that.

Thus, because we are rapidly advancing along this non-sustainable course, the world's environmental problems will get resolved, in one way or another, within the lifetimes of the children and young adults alive today The only question is whether they will become resolved in pleasant ways of our own choice, or in unpleasant ways not of our choice, such as warfare, genocide, starvation, disease epidemics, and collapses of societies. While all of those grim phenomena have been endemic to humanity throughout our history, their frequency increases with environmental degradation, population pressure, and the resulting poverty and political instability.

More and more, men are beginning to understand the severity of the problems which face them today. On all fronts — political, economic and social — these problems multiply and cause much heartache and sad shaking of heads. Add to these the environmental problems which man’s cavalier attitude to nature and its resources has engendered, and the future for mankind looks bleaker still. The realization is dawning that mankind’s life is in crisis and that something radical must be done before it is too late.

The major challenges facing humanity today are global – climate change, accessible fresh water, ever decreasing bio-diversity and over population. These problems call for global solutions and these solutions will require co-operation on a global scale unparalleled in history. Peace is the essential prerequisite to create the environment to achieve the levels of co-operation necessary.

The world's biggest problem is not sexism, racism, political polarization, war, or income inequality. The key never-ending crisis is that most people can't or won't think. Poor thinking skills cut cross all the usual lines to drag down societies like nothing else. Thinking well could alleviate or solve virtually all our problems.

People often ask, "What is the single most important environmental/population problem facing the world today?" A flip answer would be, "The single most important problem is our misguided focus on identifying the single most important problem!"

The real problem of humanity is the following: We have Paleolithic emotions, medieval institutions and godlike technology. And it is terrifically dangerous, and it is now approaching a point of crisis overall.

At the beginning of the 21st century peace has become pivotal to the survival of society as we know it. The major challenges facing humanity today are global – climate change, lack of fresh water, ever-decreasing biodiversity and over-population. It is hard to over-state the devastating effects that these problems will have on business unless global actions are taken that have the agreement of most nations. No nations or individuals will be untouched.

Back then (in 1985) the issue of the day was nuclear testing, now we are faced with problems such as climate change, overfishing, deforestation, shipments of radioactive materials through Pacific waters and nuclear proliferation. We need to remain vigilant so that we won't become victims again.

The world's problems are pressing in on us all. The scale and impact of human activities now affects a great portion of the global resources important to human welfare. These activities are putting growing, often destructive pressure on the global environment, pressure that appears likely to increase as human numbers swell toward the doubling of the world's population that evidently lies ahead. These pressures can spawn or aggravate conflict that. in a world with so much destructive weaponry, generates important national security problems. Great changes are necessary to help ensure a humane future for the generations to come. Most of the world's scientific community and many people in the environmental movement are aware of the gravity of the problems. Yet despite sober warnings from these and other groups, in both the industrial and the developing world, re- medial efforts frequently appear powerless and ineffectual. The scientific community has not taken a sustained, powerful role in the public arena where this great cluster of issues is debated and where the problems must be resolved. There is much more that our community can contribute to assessment, warning, and proposals for new patterns of behavior.

All the problems that disturb us today—the cutting down of forests and the erosion of the soil; the emancipation of woman and the limitation of the family; the conservatism of the established, and the experimentalism of the unplaced, in morals, music, and government; the corruptions of politics and the perversions of conduct; the conflict of religion and science, and the weakening of the supernatural supports of morality; the war of the classes, the nations, and the continents; the revolutions of the poor against the economically powerful rich, and of the rich against the politically powerful poor; the struggle between democracy and dictatorship, between individualism and communism, between the East and the West—all these agitated, as if for our instruction, the brilliant and turbulent life of ancient Hellas. There is nothing in Greek civilization that does not illuminate our own.