Since 1900, the level of the ocean has risen 17 centimeters, causing erosion of up to 20 meters of coastland on the eastern shore of the United States. However, this is insignificant compared to the projected rise of the oceans due to global warming. The rising temperatures cause melting of the polar ice caps, and experts speak of a full 1-meter rise in ocean level by the end of this century.

If the polar ice caps should melt in their entirety (which is highly unlikely), enough water will be released to raise the ocean level by at least 65 meters -- but we have no desire to speculate further on what might be, in this worst-case scenario.

The phenomenon of the earth being covered with water is mentioned in Torah sources as part of the prophecy of Redemption. Maimonides, at the conclusion of his monumental work of Jewish law, Mishneh Torah, describes the era of Redemption using this quote from Isaiah: "And the world will be filled with knowledge of G-d like water covers the ocean bed."

This knowledge of G-d spoken of by the prophets does not refer to mere information or scholarship. It is not the type of knowledge that comes through the usual channels of study and exploration. As the verse says, "No man will teach his friend, for they will all know Me, from the smallest to the greatest." We will not know G-d through lectures or books. We will have a direct, personal experience of G-d, as real as life itself.

Chassidic teachings explain that water is a metaphor for unity. Water molecules tend to stick together closely, which contributes to water’s high boiling point and high temperature of evaporation. Normally, as individuals we have a strong sense of ourselves, distinct from the people around us. However, as knowledge of G-d covers the earth “as water covers the oceans,” we will lose the illusion of separateness, and see ourselves as part of a unified whole. Our identification with G-d will cause us to sense our essential unity. The joy of others will give us joy; our fears and burdens will be shared.

And, perhaps, the global unity we will feel in the times of Moshiach will give us the impetus to find a solution to rising global temperatures, not motivated by self-interest but out of concern for the welfare of everyone.

Prof. Yirmiyahu Branover is chairman of the Center of Magnetohydrodynamic Studies and Training at Ben-Gurion University.