Responding to Mr. Hunter’s comment that the ozone crisis just went away. On the contrary, here are some facts. There was enough scientific evidence regarding the causes and the dangerous medical effects of ozone depletion that the Montreal Protocol, the first of several comprehensive international agreements, was enacted in 1987. These agreements halted the production and use of ozone-depleting chemicals, such as chlorofluorocarbons used as propellants in aerosol cans. As a result, the ozone layer has been increasing rather than being depleted. That is why we don’t see increases in the rates of skin cancer, eye cataracts and immune system damage. Sunglasses and lotions alone cannot protect us sufficiently.

Using Mr. Hunter’s theory, we would not have needed to do anything about many other crises due at least in part to human activities. For example, many rivers were contaminated by toxic chemicals, such as PCBs; they did not simply clean themselves up. It took humans changing their activities.

The effects of climate change are obvious. Ocean levels are rising, droughts, massive floods and many other climate problems are increasing, which will affect all life on earth. Increasing global temperatures are affecting our global food supply and reducing the nutritional values of foods, such as rice and wheat. Mr. Hunter insists climate crises will just “pass,” yet he writes that we can find solutions to this crisis. That’s a basic contradiction. Only if we acknowledge that climate change is a crisis will solutions be sought.

Joe and Ann Delmastro

Idaho Falls