Not only does the way we treat the environment affect human health, but it also has drastic affects on other living creatures that require sustenance and safe habitats to survive. Our environment is continually changing, causing habitats to be altered and modified. Natural changes tend to occur at a gradual pace, usually causing only a slight impact on individual species. However, when changes occur at a fast pace, there is little or no time for individual species to adapt and adjust to new circumstances, which can create disastrous results. Rapid loss of habitat, predominantly caused by human beings, is the primary cause of species endangerment. Nearly every region of the earth has been affected negatively by human activity, particularly during this past century. The loss of microbes in soils that formerly supported tropical forests, the extinction of fish and various aquatic species in polluted waterways, and changes in global climate brought about by the release of greenhouse gases are all results of human activity.
It is difficult to identify or predict human effects on individual species and habitats, especially during a human lifetime. But it is quite apparent that human activity has greatly contributed to species endangerment. For example, although tropical forests may look as though they are lush, they are actually highly susceptible to destruction. This is because the soils in which they grow are lacking in nutrients. It may take centuries to re-grow a forest that was cut down by humans or destroyed by fire, and many of the world's severely threatened animals and plants live in these forests. If the current rate of deforestation continues, huge quantities of plant and animal species will disappear.
In addition to the indirect impact of human behavior on the animal world, Judaism decrees moral treatment of animals over which we exercise direct control. There are moral and legal rules concerning the treatment of animals, which are based on the principle that animals are part of God’s creation towards which humanity bears responsibility. Scripture makes it clear that not only is cruelty to animals forbidden, but also that compassion and mercy are demanded towards them.
Jewish tradition teaches us to care for “the Earth and all its inhabitants” -- to preserve that which God created. After the Great Flood described in Genesis, God declares that the Covenant established is between God and all the creatures on the planet. (Genesis 9:9). In the midrash we learn: “Even things that you may regard as completely superfluous to the creation of the world, such as fleas, gnats and flies, even they are included in the creation of the world and the Holy One carries out the Divine purpose through everything – even a snake, a scorpion, a gnat or a frog” (Midrash, Genesis Rabbah 10:7).
In later rabbinic literature, the laws regarding treatment of animals are referred to as tzaar baalei chayim, prevention of cruelty to animals. Under Jewish law, animals have some of the rights humans do. Animals rest on Shabbat, just as humans do. We are forbidden to muzzle an ox while it is working in the field, just as we must allow human workers to eat from the produce they are harvesting. We are permitted to violate Shabbat to some extent to rescue an animal in pain or at risk of death, just as we are prescribed to do for humans under the ordinance of pikuach nefesh, the obligation to save a life in jeopardy. Our Rabbis also further dictated in Talmudic times that a person may not purchase an animal unless they have made provisions to feed them, and a person must feed their animals before they feed themselves.
It has become customary to recite Psalms on Tu B’Shevat, among them Psalm 104. This Psalm speaks of God's concern and care extended to all creatures, and illustrates that God created the entire earth as a unity, in ecological balance: "You make springs gush forth in torrents;; they make their way between the hills, giving drink to all the wild beasts; the wild asses slake their thirst. The birds of the sky dwell beside them and sing among the foliage. You water the mountains from Your lofts; the earth is sated from the fruit of Your work. You make the grass grow for the cattle, and herbage for man's labor, that he may get food out of the earth, wine that cheers the hearts of men, oil that makes the face shine, and bread that sustains man's life" (Psalms 104:10-16).