Ten Teachings on Judaism and the Environment by Rabbi Lawrence Troster - Teaching Six

6. The Torah prohibits the wasteful consumption of anything. In Judaism, the halakhah (Jewish law) prohibits wasteful consumption. When we waste resources we are violating the mitzvah (commandment) of Bal Tashchit (“Do not destroy”). It is based on Deuteronomy 20:19-20: “When in your war against a city you have to besiege it a long time in order to capture it, you must not destroy its trees, wielding the ax against them. You may eat of them, but you must not cut them down. Are trees of the field human to withdraw before you into the besieged city? Only trees that you know do no yield food may be destroyed; you may cut them down for constructing siege works against the city that is waging war on you, until it has been reduced.” This law was expanded in later Jewish legal sources to include the prohibition of the wanton destruction of household goods, clothes, buildings, springs, food or the wasteful consumption of anything (see Rambam, Mishneh Torah, Laws of Kings and Wars 6:8, 10; Samson Raphael Hirsch, Horeb, 279-80). The underlying idea of this law is the recognition that everything we own belongs to God. When we consume in a wasteful manner, we damage Creation and violate our mandate to use Creation only for our legitimate benefit. Modesty in consumption is a value that Jews have held for centuries. For example one is not supposed to be excessive in eating and drinking or in the kind of clothes that one wears (Rambam, Mishneh Torah, Laws of Discernment, chapter 5). Jews are obligated to consider carefully our real needs whenever we purchase anything. We are obligated when we have a simchah (a celebration) to consider whether we need to have elaborate meals and wasteful decorations. We are obligated to consider our energy use and the sources from which it comes.

Time Period: Contemporary (The Yom Kippur War until the present-day)