Global Warming: What We Don’t Know

global warmingI just read a long exchange among scientists about global warming, in which they, sometimes harshly, argued against each other from opposite sides of what seems to be a great divide. Most of us know so little about how a climate works and how it might change that we must rely on distant experts to tell us what is going on and what might happen in the future.

I was struck by the agreement among these arguing scientists that significant warming had occurred across the earth, and that it could have major effects on human life. The scientists disagreed about the past and the future: what caused the warming and how much further warming is likely?

We don’t know the answers to these questions. Each model of climate change predicts a slightly different future.

We do know that global warming has occurred. 2010 was the hottest year on record, tied with 2005. Each year since 2001 has been hotter than any year before 2001, except for 1998. Last month was the hottest March on record in the US.

A warming climate could mean the end of maple syrup production and the proliferation of tree-killing insects, just to name two of many inevitable changes. If the trend of warming continues for the next 20 years, the odds of catastrophic floods in our coastal cities rise to dangerous levels.

Some things about global warming are uncertain. But one thing is not – if we do nothing, we will face enormous problems which could have been avoided.

We don’t know exactly how humans evolved from apes. Very recently another fossil find in Africa added a new species, not yet named, to the now long list of almost humans. We do know that evolution, working incrementally over millions of years, has allowed humans to develop larger brains, which in turn permitted us to make tools, create language, and build civilizations which lower animals could never dream of.

We don’t know exactly how the many chemicals which we have synthesized and then used all over the earth affect our health. An article on WebMD says, “How much hormone is in a hamburger, and could it hurt you? The answer is, no one really knows.” But we do know that pesticides can cause cancer, as do some of the additives fed to the animals we eat. The Food and Drug Administration has known for decades that putting antibiotics into animal feed to make them put on weight can cause more resistant strains of human diseases to develop.

We know that human inventions, created to make life better, can make life worse in unpredicted ways. Asbestos, lead, and mercury were employed in a wide variety of materials in our homes, because they appeared to be useful, until scientists realized that they were also toxic to humans. Then it took years to get them out of our daily lives.

A major uncertainty today is how much the process known as fracking, the injection of chemicals under high pressure into rock to release natural gas, could harm our health. Scientists in many states have documented that fracking contaminates water supplies, causes small earthquakes, and pollutes the air. But exactly how and how much is not certain, because the studies are scattered, and the oil and gas industry vociferously denies any dangers from fracking.

Although the vast majority of scientists in every nation agree that global warming caused by human activity will continue to levels dangerous to our society, the media and some politicians in the US continue to stress uncertainty. Americans are so confused by the claims of public figures that global warming is a “hoax” that a Rasmussen poll last year showed the majority distrusted science: 40% thought it was very likely and 29% thought it was likely that scientists have falsified global warming research.

There is no evidence for such falsification, just the wishful thinking of those who don’t want to face uncomfortable reality.

Here’s one thing we do know. Science works.

Tornado prediction is an even less certain science than global warming. Yet weather scientists were able to broadcast the earliest tornado warning in years and save lives across the Midwest earlier this month. Despite the uncertainties of such forecasts, weather science was on target.

Steve HochstadtGreat and powerful people have argued against accepting the basic findings of science since well before Galileo. They have always lost, after a long, tiring, and wasteful battle. Their political unwillingness to accept science squanders society’s precious time, which it needs to face the real question: what does the science mean for us?

That question is devilishly difficult to answer. It’s the main thing we don’t know.

Steve Hochstadt
Taking Back Our Lives

Posted: Monday, 23 April 2012

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Comments

  1. JoeWeinstein says

    What IS known is that man-caused greenhouse gas (GHG)  emissions of recent centuries – and continuing right now at the fastest clip ever – have pushed up the GHG content of the lower atmosphere far beyond anything seen in the carefully retrieved ice-core records of at least 3/4 million years – many cycles of ice ages and thaws. 

    If the oceans continue to dissolve a lot of the GHG, we will get unprecedented ocean acidification.  The start of that is now being observed.  Whatever extra GHG does NOT get dissolved will keep raising the heat content of the planetary surface and air.  That means some combination of all the following effects:  more wet-atmospheric warmth and capacity to carry storms – which seems to be happening; overall hotter dry air – which also seems to be happening;  and melting or floating off large land-based ice sheets and thereby raising sea level and flooding coasts – which also seems to have started.   

    What is not known is the precise mix – i.e. relative strength – of these separate consequences:  which ones will be strongest – and when. 

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