Wednesday, June 6, 2018

Regional Solutions to our Global Problem?

The art shown to the right is "borrowed" from Energy and Environmental Chemistry, a journal of The Royal Society of Chemistry.  When I saw it I thought, Wow! What an artful, fully-packed summary of so many ways in which humankind is responding to the challenge of Global Warming.
Bear with me for a bit while I touch upon some features of this graphic. Notice first that carbon dioxide, CO2, the most important greenhouse gas, is featured in a big way. Greenland is up front, to remind us of the prospects of sea level rise and climate changes resulting from melting of the glaciers. The array of orbiting satellites at the top is a reminder that we have powerful and reliable means of keeping track of many aspects of the planet’s condition.  Notice also the prominence accorded to solar panels and wind generators. And, very importantly the trees and other vegetation, and what I take to be subterranean activity, are highlighted as essential components of efforts to restore the planet to a natural, sustainable balance.
The mathematical expressions represent the modeling of air, oceans and land mass usage to ascertain what policies and actions would be most efficacious for mitigating climate change.  The figures at lower left represent the cooperative actions of scientific and governmental entities to address the challenges ahead.   
But will the governments of the world continue to fund this and a host of other scientific activities devoted to eventually mitigating global warming?  The man who currently holds the title President of the United States, a position until recently spoken of in terms of “world leader”, doesn’t show much interest in this topic. Dana Nuccitelli, writing recently in the Guardian, pointed out that he failed to mention it his 2018 State of the Union address. However, he did pick up on withdrawing from the Paris Accords, which he was apparently told was a good idea because it would help American businesses and workers. Actually, I don’t know that he was told that—it was surely what his base and the likes of Senator “snowball” James Inhofe want to hear.
Despite all the political noise, and other distractions, the work of saving humanity from colossal disruption goes on.  The issue of Energy and Environmental Science that features the cover above has an important paper by a group of authors from the UK and the US, on how COemitting power plants at the level of states or regions could cooperate to produce massive reductions in emissions.  The idea is to take advantage of situations in which parties can work together.  The authors use the example of the Clean Power Plan, enacted during the Obama administration by the EPA in August, 2015.  It ran until March 2017, when the Trump administration issued an Executive Order to review the rule so as to suspend, revise or rescind the program.  The CPP had been the Obama administration’s flagship program in climate change mitigation.
The authors have come up with what they refer to as an “emissions reduction cooperation model”.  There’s not space here to go into details; it assumes that the parties will engage in interregional cooperation by following a sophisticated optimization model, with fair sharing of dividends from cost savings. The authors predict that if the plan were enacted in the US, and if at least half of the states cooperated, the cost of electricity generation could be reduced by $41 billion per year, while CO2 emissions would drop by 68% as compared with 2012 levels. It does not appear to require a lot of governmental participation, though individual states would need to take actions.
We know we have a global problem: the earth is warming because of an increasing atmospheric concentration of greenhouse gases. But humans have only recently taken charge of the planet.  We started only about 60,000 years ago, so we’ve not had much practice at solving problems at a global level. In fact, consider how recently we came upon the realization that the planet is a globe!  There doesn’t seem to be a reliable way to keep track of relative advantage in global-scale action plans.  But the “emissions reduction cooperation model” assumes that one important element in the global warming picture could be addressed on a regional level in the here and now to the mutual benefit of all participants.  From what I’ve been reading, I gather that there are other sectors where big benefits could come from taking actions at the regional or national levels that shake up the present system of allocating profits and other benefits—major shifts in agricultural practices toward regenerative methods, for example, or reforestation.  Much can be accomplished with cooperative actions that would save money and conserve the environment—to the benefit of all, except those who’ve profited inordinately from past policies and practices tailored to the wishes of just a few. 
Studying the figure at the top has caused me to feel once again a sense of pride in being a scientist. We will not work our way through the challenge of climate change without science as a guide to action.  I felt so good about being a scientist that I went to the online store of the Union of Concerned Scientists and bought a T shirt that says, "Stand up for Science".  I don't really need another T shirt.

Tuesday, May 29, 2018

The rising and falling of the seas

The figure to the left shows the ordering of Earth’s geological periods, going back about four and half billion years.  Homo erectus, our ancestors, showed up during the Pleistocene epoch, which lasted about 2.6 million years, as evidenced by the geological record.  During the Pleistocene the climate underwent a series of dramatic swings, producing alternate periods of glaciation and warming periods that led to major retreats of the glaciers.  Homo sapiens—the first humans, you might say—showed up about 200,000 years ago. The little boxes denoting the different epochs in the figure are not to scale.  If they were, the Pleistocene would be a very narrow box, and the Holocene would be just a line. We humans are very recent entrants onto the stage of Earth’s evolution. 
The Holocene represents the major retreat of the last wave of glaciation.  The glaciers covered Canada, dipped down into what is now the Midwest, covered New York and all of New England.  It was only 11,700 years ago that the most recent major glaciers retreated.  The climate since then has been relatively stable, with no periods of dramatic change.  It is this stability that enabled humans to expand from the tropical regions toward the poles, especially in the northern hemisphere.  In their retreats, those massive glaciers gouged out the Great Lakes, and their movements ground rocks to a fine powder that, along with sand, covered land surfaces and formed the base for seeds to germinate and form the vegetation that eventually covered much of the land.
During this time Earth’s climate was determined in large measure by the amount of carbon dioxide, CO2,  in the atmosphere. Climatologists and geologists have developed powerful means to measure CO2 levels in the past several million years, and have also been able to reliably estimate atmospheric temperatures over this same period. The two are strongly correlated.  On the basis of this and much corroborating evidence, we can be quite sure that an increase in atmospheric CO2 level produces warming, which in turn results in melting of glacial ice and an increase in sea level.
The table above should bring home the fact that we’re such newcomers to the planet!  Humans have no real experience with major climate change.  The Holocene is regarded as a period of quite stable climate as compared with earlier epochs, long before humans made their debut.  The geological record and ocean sediments, provide evidence that there were periods in Earth’s history that were truly overpowering, that changed nearly everything.  The Russian scientist, Mikhail Budyko, was one of the pioneers of studies on global climate.  He produced a simple physical model of equilibrium in which the incoming solar radiation absorbed by the Earth's system is balanced by the energy re-radiated to space as thermal energy. The results of his calculations were startling.  In 1972, he calculated that a 50% increase in atmospheric CO2 would melt all the polar ice, whereas reducing the CO2 level by half could lead to a complete glaciation of the Earth.  Budyko was not the first to advance these ideas.  For example, the Swedish scientist, Svante Arrhenius, had come to similar conclusions much earlier.  But Budyko had a quantitative model.   He predicted that if ice sheets advanced far enough out of the polar regions, a reinforcement could occur whereby the increased reflectiveness of the ice led to more cooling and the formation of more ice, until the entire Earth was covered in ice.
His prediction regarding loss of the polar ice is being borne out; as the CO2 the arctic ice is diminishing year by year, and is likely to be completely melted in the summer months in 20 to 30 years. But what about that other prediction? Was there ever a time when the CO2 level was so low that the planet was covered with ice? It’s hard to imagine, but evidence that Earth was once completely glaciated, the so-called Snowball Earth hypothesis, has been accumulating.  The American climatologist Joseph Kirschvink published a paper in 1992 in which he argued that the presence of banded iron formations in certain geological deposits is consistent with such a global glacial episode. It happened very long ago, 650 million years back, in the Proterozoic Eon (see the figure). But once such a frozen landscape is formed, what could break the planet out of such a frozen state?  Several mechanisms might have been at work.  One candidate is that CO2 began to accumulate from volcanic outgassing. There could have been plenty of that going on during those long-ago times.
I recently ran across a paper in Science, entitled: “Rapid sea level rise in the aftermath of a Neoproterozoic snowball Earth”.  It was my introduction to the idea of “Snowball Earth”.  Naturally, I had to read it. If Earth’s surface were covered with ice, what was the sea level under all that ice? The gist of the paper is that, with so much water being tied up as ice, the level of the liquid ocean underneath it had to be much lower than it is today.  Scientists can only guess, but they estimate that the water level would have been from about 0.7 to 1 mile lower than today.  So when conditions suddenly changed, and the glaciers began melting at a furious rate, sea levels rose, scientists estimate, about 100 times faster than at present—on the order of a foot a year.
We humans seem to have been programmed by evolution to think short term.  That characteristic is coming to haunt us in dealing with global climate change today.  We have trouble focusing on events likely to ensue in the future, even if they’re only a century away.  We should be thinking about the possibility that glacial melting could come more rapidly than scientists now estimate. There’s a lot we could be doing to head off some of projected global warming, but we seem content to put it off.  It may be tempting to buy a pricey home or condo near the water, but future rates of sea level rise could make that an even poorer investment than it now seems to be.


Tuesday, May 8, 2018

What about China?

Those of us who live in the United States or a European country, and who fret about the future of the global climate, have an understandable tendency to focus on what’s going on in the so called western region of the world.  We might be upset with the Trump administration’s policies regarding the uses made of federal lands, or with rollbacks of legislation having to do with emissions from coal fired power plants.  We of course should be concerned—dismayed at the undoing of laws and regulations that affect our well-being in the here and now, or failures to join with other nations of the world in setting goals for drawdowns of CO2 emissions in the years ahead. But if we are to be effective advocates for policies and practices of global significance we need to keep in mind our place in the global picture.  There’s no better way to put this into perspective than to think about China.  I recently ran across a paper published in the Proceedings of the National Academy of Science, entitled Climate Change, human impacts and carbon sequestration in China.  China is now the world’s second largest economic entity, next to the United States.  That’s impressive, but even more important is the fact that China is changing more rapidly than any other major national socioeconomic system except possibly India. These changes are inexorable, and the implications for the planetary climate are profound. China is a large and powerful entity in its own right, and it exerts immense influence on a surrounding region that embraces a substantial fraction of the world’s population.  As China goes, so also will a good bit of the rest of the world.
Let’s look at this graph, lifted from the PNAS research paper I alluded to above.  It reveals some important facts and projections:

The upper part of the figure is easy to follow.  The blue line shows the growth of China’s Gross Domestic Product (GDP).  You can see that it’s shot up like mad in the past decade, and it continues to climb at a furious rate.  Then look at the green line, which shows population over time. Two important things:  China’s population is not increasing, and in all likelihood it will not do so in the future.  But it’s already huge. At 1.37 billion people, its population is about 4.3 and 2.7 times greater than that of the United States and the European Union, respectively.   The third line on the graph shows the rate of CO2 emissions.  These have been increasing rapidly as China looks for the energy to propel its social and economic development.  The major fuel for this is coal.  In 2013 China accounted for about 27% of global CO2 emissions.
The timeline below the graph tells a powerful story. Mao Zedong, the founder of the People's Republic of China was responsible for the disastrous policies of the 'Great Leap Forward'.  Between 1958 and 1962, a third of all homes in China were destroyed to produce fertilizer and the nation descended into famine and starvation.  In his misplaced monomania about producing an agricultural revolution, Mao mandated vast deforestation and conversion of natural ecosystems to cropland. By the time reforms were enacted, huge damage had been done to China’s ecosystems.  Then the economic growth that came with reform drove massive increases in coal burning, with accompanying pollution.  To quote from the PNAS paper:
“Fast economic development can be detrimental to the environment through land-use change, consumption of resources, and pollution. For example, land conversion to agriculture in northern China resulted in a drastic decline of the groundwater table and associated water shortage. China’s application of chemical fertilizers and pesticides accounted for about 36% and 25%, respectively, of the global usage. Fast economic development, along with the lack of strong environmental regulation, has resulted in severe and widespread air, water, and soil pollution in China: a quarter of the nation’s cities are affected by acid rain; soil erosion affects 19% of its land area; about 75% of lakes are polluted; and 15–20% of the country’s species are endangered. CO2 emission reduction in China is thus not only essential for achieving the global emission-reduction target but also critical for its own environmental protection and sustainable development.”
China is making strong efforts to reverse the policies of the past and to restore ecosystems, even in the face of enormous pressures to maintain its economic gains. C emissions per unit of GDP will be reduced by 60–65% from the 2005 level; the share of nonfossil fuels in the energy mix will be increased to 20%; forest volume will increase by 31.6% relative to the 2005 level. 
Consider the percentages of energy production that are renewable, as of 2015:  China 25%; Germany 32%; United Kingdom, 27 %; United States, 14%.  Just to keep us a bit more humble humble about all this, Denmark comes in at 69%. We in the US have a long way to go, and every reason to try to do better.  
Bottom line for me is that Drawdown must be a global movement if it is to succeed.  We have a lot to do at home, but we should be active in responding to actions our government and large corporations take all over the globe.

Tuesday, May 1, 2018

Regenerative Agriculture

Regenerative soil practice
Image result for google images of regenerative agriculture
I’m very heartened by what I’m picking up on the web regarding activity related to regeneration of soil.  This might seem to the uninitiated as a very ho-hum subject, but it’s not.  Regeneration of soils that have been degraded over time by agricultural practices and restoration of prairies that have lain fallow and unproductive of plant growth, has the capacity to sequester huge quantities of carbon dioxide from the atmosphere.  The soil C pool (I’ll use C to indicate carbon sequestered in the soil, directly equivalent to atmospheric CO2) is estimated to be about 3.3 times the CO2 in the atmosphere.  In pre-agricultural times the organic carbon sequestered in soil was much greater than it is today.  It’s estimated that conversion of natural to agricultural ecosystems has caused depletion of the stored carbon in soils by as much as 60% in the temperate regions and 75% in cultivated tropical soils.  Worldwide, these losses have translated into a substantial enrichment of atmospheric CO2.  One way to reverse this process would be to transfer CO2 into long-lived pools of organic plant matter, by judicious use of arable land and environmentally sound maintenance of plant ecosystems generally.  In other words, we need to return soil to something like its pre-human conditions.  How can this be done?  A great place to start learning about this subject is an article entitled “Can Dirt Save the Earth?” in a recent issue of the Sunday New York Times.  In general, the restoration of the soil carbon pool includes woodland regeneration, no-till farming (see the figure at top), use of cover crops, nutrient management, agroforestry practices, and growing energy crops on spare lands. The largest potential for applying regenerative soil methods is in conventional agriculture.  Ben Dobson has a nice YouTube presentation on how this works. 
Regenerative agriculture practices can be scaled up, but it will mean changing the mindsets of big agricultural interests.  In  the book Drawdown, which I’ve mentioned in an earlier blog, regenerative agriculture is 11th out of the 100 individual initiatives in terms of the total amount of CO2 each can remove or potentially avoid.  The economics estimates by the Drawdown team, thoroughly reviewed by a large and distinguished Advisory Board, are impressive.  It would cost on the order of $57 billion net to convert 1 billion acres of land to regenerative agriculture by 2050.  That’s relatively little to spend over 30+ years period.  On the other hand, the savings would be on the order of $ 1.9 Trillion!  There is space here for me only to suggest where those savings come from—less water, reduced use of insecticides, pesticides and synthetic fertilizers, less utilization of heavy machinery; the list goes on.
In the transition to agricultural societies about 10,000 years ago, human dependence on soils became more direct.  Cultivation of virgin soils exposed them to loss of topsoil during seasonal rains The loess plateau of north China, for example, began to erode more quickly under human management, earning the Yellow River its name. We humans have had a long history of despoiling land, breaking the sods of steppes and prairies.   We have come to the point where we must retrace our steps, and not just because of rising CO2 levels.  We are once again coming to a hard won realization that nature is a deeply connected web of existence.  Grossly disturb one part of an important ecosystem, and see the effects ripple outward.  Planet Earth is becoming increasingly crowded.  Land available for producing food will become increasingly dear. It never was a good idea to allow topsoil to blow away in dust storms or wash down streams and rivers into the oceans, losses caused largely by repeated tilling.  We will have to work our way back to something resembling the natural state of the land, with the complexity of life forms able to sequester CO2, produce needed nitrogen, and sustain a vigorous agriculture. 

Friday, April 20, 2018

Little trash, big trash

                We’ve learned all too well that the fruits of modern science and technology have a way of turning into trash—replaced by improved versions, just worn out or made obsolete by new inventions. We’ve also become used to clever disposable devices such as medical inhalers and men’s shavers, that involve complex packaging not easily recycled.  Some discarded stuff, pitched from car windows or blown off the tops of garbage trucks, is an affront to the senses, but it can be picked up eventually.  More insidiously, huge quantities of plastic waste pass through water treatment plants and trash burners, and in various ways get mismanaged.  They are eventually ground into tiny pieces, referred to as microplastics. They’re everywhere: in the oceans, freshwater and terrestrial environments.  In the oceans they are found in every marine species at every level of the food chain, from the ocean’s surface to its floor, pole to pole.  Most water systems are also contaminated with medications and industrial chemicals that zip right through municipal water treatment plants.  So there’s room for a lot of worry about the world of what we might call “little trash”, and not so many bright ideas for how to deal with the problem.
“Little trash” is a collection of serious challenges. In this blog, though, I want to talk about “big trash”: TV sets, laptop computers, cell phones and the like. All such devices contain a lot of metals: lead, cadmium, gold. It would be nice if all such devices were recycled, to recover metals that are actually valuable in their own right, but that could someday find their way into our environment as toxins if simply pitched into landfills. Separating the valuable components from one another and from the metallic chasses and plastic frames is not easy. Many companies accept old products and do the work of separation, but sadly, only about 10 percent of the gold in such devices is actually recovered.  Landfilling is easier—let’s get that new laptop out of the box!
Then there's "big trash", the flood of waste disposal of old renewable energy devices, such as solar panels, batteries from hybrid and electric cars, and old wind energy machines. Renewable energy devices have a limited lifetime. If we can’t recycle them, or if it’s too energy-demanding to do so, we will not have advanced toward truly carbon-free energy production.  Consider the wind turbines seen in increasing numbers across the landscape. Wind energy is a rapidly growing segment of the world’s energy mix. The European Union projects that wind will provide about 14% of total energy by 2020. Let's look at what one of these wind machines involves.  GE has a model that generates up to 1.5 megawatt of electricity.  As you can see from the opening photo, the blades on this monster are big: 116 ft in length, they weigh several tons each.  With each new model they’re getting bigger.  The blades of the current GE model are composed of a glass fiber and polymer blend, with perhaps other materials included, designed to give maximum strength and durability.  The blades are expected to last for 20 to 25 years.  Taking down and putting up, transportation across distances and assembly into a working whole, are major projects.  (There’s also the matter of the gigantic base needed to support a single wind tower.  Fortunately, that should not wear out, so it doesn’t present a recycling challenge.)
Disposal of the old, turbine blades will in time become a big problem. The wind power industry added more than 8,200 megawatts (MW) of capacity in 2016.  It now supplies more than 6 percent of U.S. electricity. Various means might be employed to recycle turbine blades as they wear out.  There are no easy solutions, and all of the possibilities require energy.  But the problem is being worked on.  As so often happens in such situations, inventive people turn challenges into new possibilities.  Let’s hope that creative solutions are found for recycling solar panels and electronics.
 Because recycling has such profound consequences for the health of living systems, governments of the industrialized nations should be concerned about all of this. Where is the US EPA on this topic?  Judging from what I’ve been reading lately, the director of the EPA is likely to be sitting in a sound-proof booth, the better not to hear of such vexing matters.  Burning more coal or natural gas is, of course, no solution, but it goes down well with the base.  Ironically, those folks are the ones who stand to suffer most from inaction on the environmental front.

Monday, April 16, 2018

A new Start

This blog has gone quiet for a long time.  Life put too many things on my plate, and I just had to let some things go adrift for a time.   In the meantime, environmental politics have turned worse at the national level, and there’s no sign of slowdown in the rate at which CO2 is being added to the atmosphere. I believe it’s time for me to restart the blog.  I have no illusions about the importance of any pushback I might generate, but there are new things to say, new dragons to go after, perhaps new readers to attract.  We’re told that there are many hopeful signs for the world’s environment if we just look for them and lean into the future.  Renewable energy technologies have been making substantial progress.  And of late there’s new interest in taking assertive actions to actively draw down the levels of atmospheric CO2, and address social factors that bear upon the rates of CO2 emissions.  
Realistically, even with the best efforts of all those on the right side of conserving this planet in a livable state, our progeny are in for difficult times.  But we can get going on doing remedial important work.  I’m enthused about Drawdown, a comprehensive plan to actually reverse global warming through an array of initiatives extending over energy, food, the status of women and girls, land use, transport and materials.  The book, Drawdown, edited by Paul Hawken is exciting in its ambition and comprehensiveness. The Drawdown team proposes 80 “solutions”, steps that are cost-effective and doable, each of which can reverse or mitigate the rate of increase in atmospheric CO2.
Presently we’re faced with the likes of Scott Pruitt and his fellow cabinet member, Ryan Zinke, to name the two most villainous critters in the Trump cabinet cage. They seem bent on reversing as much as possible of the progress made since the inception of the E.P.A. and other legislation protecting the nation’s treasured wild places.  We can and should keep pressure on our congressional representatives to do what they can to block these political hacks’ attacks on the budgets and scientific frameworks of the agencies they control. But Margaret Talbot’s excellent piece in The New Yorker tells us how tough it will be.  It’s easy to get discouraged.
 My spirits were recently boosted by re-watching Kens Burns’s wonderful series on The Roosevelts. From Teddy Roosevelt through FDR’s New Deal programs such as the Civilian Conservation Corps the legitimacy of government’s role in maintaining the commonweal was established.  We have history on our side, in terms of admiration for past accomplishments and determination to continue the fight.  Those of us who treasure a sustainable and beautiful world must not give up—we’ve got to keep pushing back, keep working for change.
Consider trees, just one aspect of the environment. Deforestation has led to loss of a significant fraction of the planet’s forests.  In the early stages of human culture, wood was used as a fuel, to provide warmth, and for cooking.  Then forests were stripped to provide land for agriculture, a process that continues to this day.  But this must not continue, not only because we need trees to contribute to the carbon dioxide balance.  Their destruction leads to loss of habitat for many of the earth’s species, and destabilization of the land, with resultant erosion and flooding. 
And who would want to be without trees?  Richard Powers, one of finest novelists writing today, has just published a new novel, The Overstory, that explores the essential conflict between humans and all the nonhuman living rest, while at the same time revealing the deeply complex webs woven in the natural world.  A lyrical, inventive and heartfelt tale worth reading.   
So now I’m motivated to write regularly, mostly about energy, the environment, food and the politics surrounding energy and the environment.  By way of introducing the topic of my next blog, let me ask a question:  What eventually happens to all the machinery, all the technological wizardry, that makes renewable energy possible?  Everything we make use of eventually wears out, right?  Cell phones, Solar panels, electric car batteries, those monumental wind towers.  If you think recycling now is difficult and complex (it is), just wait. 

Saturday, December 10, 2011

Yep, it's getting warmer

In a recent issue of Science a trio of scientists who are experts on climate modeling and interpretations of data related to global climate summarize the best available information on variation in Earth’s surface temperature over the past half century or so. Their work addresses a controversial subject that those resisting the idea of global warming love to talk about.
Doubts about the reality of 20th century warming have been fueled by a veritable blizzard of misinformation and outright denial by politicians such as Senator James Inhofe and talk show hosts such as Rush Limbaugh and Glenn Beck. The political winds from the extreme right have been blowing so mightily against the notion of global warming that the front-runners in the race for the Republican nomination in 2012 seem to be obliged to join in the denialist chant. The American people are being deluged with misinformation and outright lies on this topic. It is thus worth thinking about the significance of this recent work by Santer, Wigley and Taylor.
One of the most difficult challenges in the entire business of drawing conclusions about Earth’s surface temperature is that there really is no single literal measurement that gives us the temperature of the planet. I wrote about this in Chapter 9 of my 2003 book, Making Truth: Metaphor in Science. When we want to measure our own body temperature, we insert a measurement device such as a thermometer, or one of the fancier digital probes, under our tongue, in our ear or up our rectum, as the case may be. The temperature we record in this way we take to be representative of our body as a whole. This works because our bodies are designed to maintain, as closely as possible, a single temperature throughout. But planet Earth is not like that. As I write this in Estero Florida the temperature is about 80 degrees Farenheit. At the same time, my daughter living in mid-central Illinois reports that the temperature there is about 11 degrees Farenheit. It is far colder still in Antarctica. No single value represents the surface temperature of the planet . For this reason, when we talk about the surface temperature of the planet we are using metaphorical language and thought. We talk aboutEarth’s surface temperature as though the planet were a small, temperature-controlled thing like a human body or a refrigerator.
To get to something that resembles a single value for the surface temperature, scientists began with simply averaging the temperatures measured at as many places as possible at the same time, and averaging over time as well. Before the modern age of satellite measurements the estimates were pretty crude. Consider that something like 70 percent of Earth’s surface is covered with water. How do we get sufficient measurements of the vast and varied seas to produce reliable numbers? And what about remote places that are not readily accessible, or crowded urban areas where human activity generates a good deal of local heat? With satellite measurements it has become possible to collect data over a short period of time that reflects surface temperatures
over most of earth’s surface. By averaging these in a suitable way, one ends up with a single number that we call the surface temperature of the planet. It’s a metaphorical entity, not a real single temperature, but its value over time can serve as a reliable measure of the change at Earth’s surface. However, the interpretation of satellite data is not entirely straightforward. A group of scientists at the University of Alabama at Huntsville concluded in 2005 from satellite data that the planet’s surface temperature had declined since 1979. This unexpected result was used to cast doubt on the reality of surface warming.
One of the hallmarks of good science is that controversial results are subject to reevaluation and continued exploration. The satellite measurements were a new technology, and many factors needed to be taken into account in interpreting the data. Climate scientists at a California laboratory identified two serious errors made by the Huntsville group in their analyses. These were acknowledged by the Huntsville scientists, who redid their recalculations. The corrected results showed a warming trend over the entire period 1979 to present. The revised estimate, following from critical scrutiny by other scientists, represents another step forward in our ability to measure and understand the evolution of the global climate.
Modeling the terrifically complicated global climate system is difficult. The challenge is to find a model that reproduces the historical record as well as possible, considering all the uncertainties,and then to use that model to forecast the future course of climate change, assuming various scenarios regarding levels of greenhouse warming gases, energy consumption, population growth and so on. The media are filled with confident pronouncements, for the most part self-serving, about climate change from political, ideological and financial interests. When we hear what people like Rush Limbaugh, James Inhofe or Newt Gingrich are saying or are ready to get behind, we need to ask what motivates them and what is their competence to speak on the issue at hand. We should also do that with respect to scientists, whatever the issue might be. Citizens need to go behind the one-liners of politicians and talk show personalities to learn what scientists think and the evidence that supports their views. There is no scientific conspiracy to deceive the public into believing that global warming is real, and that it has the potential to cause a great deal of human suffering. Scientists are just doing their work, trying to learn more about the way the world is.
An incredible amount of research across many scientific disciplines leads to an unambiguous result: the planet is warming, mostly because of increased concentrations of so-called greenhouse gases in the atmosphere. Denying this may be politically or financially expedient, but global warming is underway and it will gain strength with each passing year. How much adverse change occurs over the next 50 years and beyond will depend on whether humanity collectively decides to do something about continued generation of greenhouse gases. There is little hope for significant action in the near future. The 2011 Climate Change Conference in Durban, South Africa, just concluded with essentially no progress in setting mandatory goals for reductions of greenhouse gases. This should not surprise anyone. We humans have evolved to possess a strong consciousness of the future, but we still live very much in the present. Our proclivity to discount the future, particularly one so distant that we will not be there to live in it, prompts us to choose present needs and desires over future consequences of our actions. That seems to be the way it is with respect to climate change. As Kurt Vonnegut was fond of saying, “So it goes…”.