By Jim Leonard

Global climate change has become a hot political topic. Do you remember the first Earth Day? Yes, it might have been a political statement also, but much of the passion was about how to save the earth from its human inhabitants.

Is the planet better off today than it was in 1970? Like most things, it depends on what you’re talking about.

Acid Rain. Based on the destruction of forests from acid rain, there were regulations placed on sulfur dioxide and other emissions. As a result, the acidity in rainfall has decreased 77 percent in the White Mountains of New Hampshire. While the acid in rain is still higher that many scientists would like, it has improved significantly.

Air Pollution. During the 1970’s, Los Angeles had 100 smog alerts because of the declining quality of air. The Clean Air Act in 1970 helped to reduce air pollution in the country. For example, Los Angeles hasn’t had one smog alert since 2003, even though traffic has increased dramatically. Emissions have decreased 60 percent in the country since the Clean Air Act.

The Ozone Layer. The ozone depleting gases more than doubled between 1970 and the 1990’s. Thanks to a global treaty, the ozone is starting to recover and should return to its pre 1980 state by midcentury.

Toxic Substances. There is little regulation of about 85 percent of the thousands of chemicals that are in use in the US. Of those that are regulated, the EPA estimates that the disposal and emissions have decreased by 65 percent since 1988.

Solid Waste. While recycling has increased fivefold since 1970, Americans still generate a lot of trash. In 2008, Americans were responsible for 250 million tons of trash about 47 percent more than in 1970.

Energy Use. Americans use about twice as much energy as people in France and Germany. Despite the improved energy efficiency in homes and businesses, Americans still use about the same as we did in 1970.

Endangered Species. With awareness of endangered species, the list has more than quadrupled since 1970. While seven species have gone extinct, 15 have recovered, including the bald eagle and the grizzly bear.

Many retirement age baby boomers remember the first earth day. Living green is often more cost effective. What are your thoughts about the state of the planet?