The reason is that we must do it or civilization will degenerate into chaos, conflict and continued degradation of the environment. Pessimism would be self-fulfilling. As long as there is the slightest chance that we can make the transition to a more secure and sustainable way of life on our planet, we must continue to strive for it. We can draw some encouragement in this respect from the evidence in our history that necessity drives change. What may seem totally unrealistic today becomes inevitable tomorrow.
European unity is a case in point.
In the first half of this century it would have seemed totally unrealistic to envisage traditional enemies that have been antagonists in two world wars would come together in a united Europe. Yet, despite the problems being experienced today, western Europe is united to an extent that would have seemed totally implausible a few decades ago. Throughout history, nations have demonstrated their willingness to devote the resources, establish the alliances and make the sacrifices required to confront risks to their security. Today the people and nations of the world are joined as never before in facing the greatest ever threat to their common security the threat to the capacity of our planet to sustain life as we know it and the accompanying risks, of economic, political and social breakdown. Only by forging a new global alliance, embracing north, south, east, west, rich and poor, can this challenge be met effectively.