The term
"Ethics" is defined by the dictionary as a "system of moral principles" that act as the "rules of conduct recognized in respect to a particular class of human actions or a particular group, culture, etc" (
http://dictionary.reference.com/browse/ethics). This definition begs the question, what should be (and is) considered moral. Without an agreed upon definition of morality, one cannot discuss properly whether ethics should be applied in the short or long-term. Is it that of Western Society? Of a specific religion? Of a specific philosophy?
Two major views about what makes an action moral or immoral are Teleological/Consequential views and Deontological views.
Teleological Philosophy believs that an act is considered moral or immoral (good/bad) based upon the consequences of the action. (Whether it creates good outcomes/avoids bad outcomes, etc).
Deontological views, on the other hand, consider an act to be moral or immoral as an inherent quality of the act itself. This is partly influenced by the acting person's purpose and motivation to act in such a way (See Kant).
A Teleological view is impossible to follow through to it's end; the consequences of an action reach far beyond what can easily be predicted or thought of, especially since we are relegated to a linear timeline and cannot see how our actions will affect "humanity's future as a whole." (For example, if a man slams on his brakes to avoid hitting a pedestrian, he may well cause a collision with the driver behind him [a repercussion he did not expect] but further, he may miss the next green light, causing him to miss his dinner date, marry a different woman, and birth the next Hitler). This concept is similar to the butterfly effect.
Deontological views make more sense to apply practically in society, helping individuals and societies by encouraging self-reflection (on one's motivations and intents) and adherence to a code of conduct that is others-centered. Morality in the present should not be compromised to serve some far-distant, hypothetical "greater good" for humanity.