when scientists predict calamity, politicians plug their ears...,

LATimes | If life were a movie, the president of the United States (probably played by Will Smith) would be leaping into action to save humankind from the calamity that a new scientific report says is about to befall the Earth.

A paper prepared by 22 international scientists and just published in the journal Nature warns that overpopulation, environmental destruction and climate change have pushed the world toward a tipping point beyond which lie irreversible, frightening alterations in the biosphere that supports life on this lonely planet.

Of course, since this is not a movie and is, instead, just another surreal election year, the scientists’ alarming analysis will go unheeded. If the report is addressed at all by Republicans, it will be dismissed as another attempt by fiendish environmentalists to destroy the American economy by reining in polluting industries. If Democrats take note, they will tout their green jobs program as a panacea and quickly move on to a different, less disturbing, subject.

The fact is the scope of the problem as described by the scientists is so immense and so intractable that denial is a natural response. Here is what is happening as we cling to our ignorant bliss and bicker about the president’s birth certificate:

• The world population has passed 7 billion and will hit 9 billion before the middle of the century. To make room for all these people, 40% of the Earth’s surface will be cleared for farms and cities.

• Continued burning of fossil fuels will spew more carbon dioxide into the atmosphere, and that will make the oceans more and more acidic and literally lethal for sea life.

• All that CO2 will continue to push up global temperatures at a rate too quick for species to adapt. That, combined with the loss of habitat, will result in a massive extermination of bugs and birds and plants and fish and other links in the chain of life that humans depend on.

In an interview for a story by Los Angeles Times reporter Bettina Boxall, the report’s lead author, Anthony Barnosky, a professor of integrative biology at UC Berkeley, seemed to resist sounding too alarmist, but it was obviously hard for him to hold back.