Wednesday, May 30, 2012

Climate, weather and history

The next few post are going to be recycled from my other blog. I don't have time to maintain two blogs, and I don't have the time, or really, the interest, to go dashing about chasing new readers. Serious bloggers are probably gasping at this point.

I'm serious about what I write about, and I want to share it with interested readers. But I'm 51 years old, I'm in a most-likely losing battle with b-cell lymphoma, and I don't feel like I have unlimited time to become a perfect, trendy blogger.

So what you see here is what you get here. To borrow a phrase from my nephew, "'s how I roll." If you haven't been here before, I'm a cow-calf operator from Nebraska -- that is, I'm an agricultural producer.

Climate hasn't been in the major media, at least not in a big way, for a while now. I think it's critical to understand that there's a difference between climate reality and climate politics. This, and the next few posts, represent my attempt to illustrate climate reality. I refuse to argue with cliches or sloganeering, however, feel free to comment and if you have a reasoned and objective argument to make, perhaps we can discuss it.

In a scientific paper published Oct. 20 in Nature, ‘Solutions for a cultivated planet’, researchers laid out an argument that agriculture is destroying the planet through land clearing, pollution, and the generation of greenhouse gasses, and will therefore be unable to feed a growing human population. In this series we’ve looked at a number of the assumptions the research team based their conclusions on, and offered a number of science-based refutations.

Like any human enterprise, modern production agriculture is not perfect. Unlike some (perhaps many) human enterprises, modern agriculture, with the invaluable assistance of land grant university and food industry research, has vigorously sought solutions whenever problems have surfaced. The proof of this is in the unprecedented quality, quantity and safety of the food supply as well as in the vast improvements in conservation and ecology practiced by farmers and ranchers in the U.S., and increasingly, in other countries.
Perhaps part of the reason agriculture has been under attack over the last few decades is fear. Most people in the developed world (about 99 percent in this country) are at least two generations removed from working with or in agriculture. Yet it is on agriculture that they rely utterly for their sustenance. Biased and sensationalistic news reporting of flawed science tends to enhance this fear. We’ll look at biased and misguided news about agriculture in a future article.

This time we’ll define climate and weather, take a close look at climate history around the globe, and explore some ideas about modern agriculture’s ability to feed the world under a warming climate and under a cooling climate.

One of the difficulties many of us have in thinking about and trying to understand the ongoing climate debate is that we tend to think that present conditions represent a sharp change from those of the near past, and that conditions of the near past were ideal and reasonably permanent. For instance, the American history taught nearly universally in this country is that Europeans essentially invaded the Americas, displaced the indigenous population, and denuded the landscape to make way for farms, destroying “old growth” forests and driving many native plants and animals to extinction.

This narrative is in some sense true, but heavily pejorative, and lacking essential context. Human populations have waxed and waned for more than 100,000 years, and whenever populations have grown, humans have pushed out into new territories. This scenario has played out countless times in every corner of the globe – including the pre-European Americas, where several civilizations were built by Asian and Pacific settlers, crested in good times, and eventually succumbed to the encroachment of new settlers arriving from the west.
Changing the landscape by farming is very different than “denuding” the landscape. Farming did bring environmental challenges, but most of these have been more than adequately addressed and those remaining are being mastered. It’s unrealistic in the extreme to think that the U.S. population can grow to 311 million without providing a food supply for those millions. Growing food alters the landscape, but it does not destroy the land or the ecology of the region, or of the planet. The planet is dynamic; landscapes and bio-populations change over time naturally. Humans are a natural bio-population and alter the landscape, as so do beavers with their dams, termites with their mounds, CO2 and CH4(methane) production, and a host of other organisms such as bacteria and fungi. In fact, no natural bio-population leaves the landscape untouched; rather, they live in symbiosis with the land.

What every crest and trough of human population, and every expansion and contraction of humankind into and out of territories has in common is a very tight correlation with climate change. Most of us tend to think the climate is essentially stable for very long periods of time. Most of us have lived through year after year climate conditions which seem unendingly similar and ordinary. Remember, though, our lives are short in geologic time scales. We’ve all heard of ice ages and tropical ages, extremes which happened long ago and may happen again in the distant future, but we imagine that they will never visit our present world or the world of the foreseeable future.

The best scientific evidence we have shows that ice ages, or glaciations, and warm periods, or interglacials, have been common on Earth for at least 2.67 million years. Science has a hard time finding climate evidence earlier than that due to the ever-changing geology of the planet. In the last 730,000 years, there is solid evidence of 10 glacial periods separated by interglacial periods. We are presently in an interglacial period which began about 13,000 years ago.

The causes of these warming and cooling cycles are immensely complex, but major factors appear to be solar activity, variations in the Earth’s orbit, nuclear and thermal activity deep within the planet, and the active geology of the planet’s crust (plate tectonics, etc.). The atmosphere and the oceans certainly contribute to climate, but react to climate driving forces. They do not in themselves drive climate. It is fair to say that Sun, orbit, internal structure and crust drive climate, while the oceans and atmosphere make weather.

Over the last 20-25 years, a small but vocal group of self-appointed experts, politicians, and news reporters have continued to sound the “human-caused climate disaster” alarm, claiming that man-made carbon dioxide will set off an irreversible “runaway greenhouse effect.” Their science, which relies heavily on computer modeling, makes little if any sense. Their predictions stubbornly refuse to come true. After not falling for more than 30 years, the sky continues not to fall. Yet somehow, governments continue to pour hundreds of billions of dollars into an effort to mitigate human influence on the climate. This is perhaps the epitome of hubris, that some believe man more powerful than the Earth or the Sun.

We humans tend to think we perform mighty deeds, and some of them are indeed remarkable, such as the ability of a tiny fraction of the population to feed all mankind. Nevertheless, our power and our abilities are as nothing when it comes to changing the climate.

But that doesn’t mean that climate won’t change. If history and geology tell us anything, it’s that climate often changes quickly – over only a few years – and those changes profoundly impact all forms of life on the planet.

Climate and weather are not the same thing. Weather is the state of the atmosphere at a particular place and time, hence the old saying that “all weather is local.” Weather can mean a blizzard here, sunshine and warmth there, a hurricane on one coast and cool rain on another. Climate, on the other hand, is the conditions which prevail over time. For instance, the Earth is presently emerging from the Pleistocene Ice Age, which ended about 13,000 years ago. Since that time the climate has been generally warming, though there have been prolonged periods which were sharply cooler and periods which were considerably warmer.

In our everyday perspective, 13,000 years seems a very long time ago. In fact, little recorded human history exists from before that time. Yet the Pleistocene Ice Age lasted for nearly 100,000 years. During that time, Homo sapiens – modern man – walked the Earth, though usually in the more temperate regions of the planet and along the edges of the glaciers. The earliest known recorded human history exists as cave paintings dating back about 35,000 years. Before that, little more than bones and primitive tools exist to tell the story of early man.

In the 13,000 years since the last ice age, there have been periods of warming and periods of cooling – times during which the planet was much warmer than it is today and life, including human life, rapidly expanded – and times when the planet was much cooler than it is today and when cold, disease, famine, starvation and extinction events drove life savagely back. Using a plethora of techniques, including ice-core sampling, geologic study, advanced chemistry and physics, scientists have identified 14 such periods.
The last warming, called the Medieval Warming Period, lasted from about 900 A.D. to 1,300 A.D. and brought the world out of the Dark Ages. Global temperature averages  were about 1.5-2.0 degrees Celsius (C) warmer than they are today. Human populations more than doubled, food was plentiful, wealth grew. This was the time in which most cathedrals were built in Europe and the Vikings colonized Greenland and Vinland, present day Newfoundland.

The Little Ice Age began about 1,300 A.D. and lasted until 1850 A.D. Though this was a cooling period, Europeans settled the Americas and the United States was born. Global temperatures fell overall, to an average of about 3.0 degrees C colder than today. While there were exceedingly harsh winters, there were also hot summers and drought. Though America was growing, it grew at a slow rate as outbreaks of famine and disease took their toll. The “starving time” of 1609-1610 which killed more than 80 percent of the residents of Jamestown Colony coincided with one of the coldest winters of the period. The Little Ice Age was a global ice age, and despite exploration of the New World and other reaches of the globe, it was an exceedingly tough time to be alive. Global human populations fell off, famine and disease was common, life spans fell and infant mortality soared.

In 1850 the Earth entered what is today called the Late Twentieth Century Warming. As with most warming and cooling periods, this period was characterized by fluctuations in warming and cooling, rather than a steady rise in global temperatures. There was warming from 1850-1940, cooling from 1940-1976, and warming from 1976 to 1998. Nevertheless, it was on balance a warming period. During this time there was remarkable growth in the human population and wealth, relatively little famine, a marked decrease in disease, amazing gains in technology, and unfortunately, remarkable gains in the lethality of warfare. Climate-wise, this period was on balance a time of very easy living.

In 1998 the global climate began to cool once again, and has fallen about 0.1-0.3 degrees C over the past dozen or so years. Thus far the cooling has caused no major disruption for life on the planet. There is no way to know whether the present cooling will continue or whether it is merely a blip in a generally warming interglacial period. Only time will tell.

As climate changes, will modern agriculture be able to feed a growing population? This is an interesting question.

If the present cooling trend eases and global climate continues to warm or stay stable for several thousand years, the answer is almost certainly yes. The real threat most humans will face will be war, rather than hunger.

It is possible that warfare or even over-zealous governmental control could spell the end of modern agriculture, at which point starvation would ensue. But it’s at least as likely that agriculture will continue to imperfectly improve, and that the human population will reach sustainable equilibrium.

But if the climate begins to cool, and Earth begins once again to slide into a glacial period, the answer is no. Crops, livestock, and humans need sunshine, liquid water and micronutrients to grow. Although some equatorial populations would survive, just as in the last ice age, technology, and most of the human population, would not.

The Earth, the climate – they will do what they are going to do regardless of our wishes. For now, perhaps it’s better to set aside silly notions about our capacity to destroy the planet and concentrate on being better neighbors, and continue to improve the lot of both humanity and the planet.

Next time: The trouble with carbon

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