Earth Is at the Tipping Point

Hot enough for you?

The East and Midwest are being hit by record temperatures day after day, week after week as heat wave follows heat wave.

Here are some recent headlines from The Drudge Report, the lively conservative news aggregator that has regularly featured the views of climate-change deniers:


AGAIN: Extreme heat warning for Midwest, Southeast…

High Heat, No Power

DC to Be Dark for Days

Gas Stations Packed, Run Dry

This all has revived talk of the crisis everyone forgot–climate change, or as they used to call it, global warming.

Here’s Seth Borenstein of the AP:

If you want a glimpse of some of the worst of global warming, scientists suggest taking a look at U.S. weather in recent weeks.

These are the kinds of extremes climate scientists have predicted will come with climate change, although it’s far too early to say that is the cause.

Borenstein quickly threw in a host of caveats—you can’t link individual weather events to massive climate changes, which occur over much longer periods of time, and sometimes extreme weather is just a freak event. Still, he cited some striking data:

Through most of last century, the U.S. used to set cold and hot records evenly, but in the first decade of this century America set two hot records for every cold one, said Jerry Meehl, a climate extreme expert at the National Center for Atmospheric Research. This year the ratio is about 7 hot to 1 cold.

Borenstein’s report was immediately trashed by climate change skeptics. He is a favorite target of Newsbusters and other conservative groups that have led the counterattack on scientists who believe in man-made climate change.

And there is some disagreement about the issue among scientists, but not much: A 2010 study found that “97–98% of the climate researchers most actively publishing in the field support the tenets of [anthropogenic climate change].” (See NASA’s website, for instance.)

Planet Earth from Space. Photo: Shutterstock.

Now a sober, exhaustive study in the prestigious journal Nature by 22 scientists from top universities in five different countries concludes that because of human actions in a variety of areas, earth may be approaching a “state shift,” a fundamental transformation in how the environment operates.

State shifts occur infrequently and when they do, they have massive impacts. Examples the scientists cite include rapid fluctuations in temperature 11,000 to 14,000 years ago that led to the extinction of half “the species of large-bodied mammals” and the “Big Five” mass extinctions in the far more distant past. The scientists write:

Humans are now forcing another such transition, with the potential to transform Earth rapidly and irreversibly into a state unknown in human experience…Once a critical transition occurs, it is extremely difficult or even impossible for the system to return to its previous state.

The scientists write that the previous transitions “coincided with global-scale forcings that modified the atmosphere, oceans and climate.” They continue:

Global-scale forcing mechanisms today are human population growth with attendant resource consumption, habitat transformation and fragmentation, energy production and consumption, and climate change. All of these far exceed, in both rate and magnitude, the forcings evident at the most recent global-scale state shift…

The Nature article has 100 citations. It’s behind a subscription wall and costs $32 to download. (You can find a good free summary here and here.) The editors are acting with an abundance of caution, and nobody is trying to sensationalize this.

Here’s the bottom line, according to lead author Anthony Barnosky of UC Berkeley:

It really will be a new world, biologically, at that point…The data suggests that there will be a reduction in biodiversity and severe impacts on much of what we depend on to sustain our quality of life, including, for example, fisheries, agriculture, forest products and clean water. This could happen within just a few generations.

I have been unable to find attacks on this month-old study’s credibility by the usual skeptics, which means it’s either beyond their comprehension or very, very solid.

So, climate change deniers, what is your answer to this? And more importantly, what is ours?

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