Climate Change – Part III – What can be done?

With the veritable amount of evidence that has been laid out before us, why is it that people aren’t concerned about global warming? Despite scientific consensus on the subject, some people think global warming isn’t happening at all. There are several reasons for this, and they cover various overlying and conflicting themes on global communication, and an incentive towards environmental action.

Beginning with the common lay-person, a popular speculation is formulated in the form of this question: If simple forecasts can’t get next week’s weather right, how is it that we can trust the predictions that have been made on the basis for decades or centuries from now?

The answer to this is quite simple, and once again highlights the necessity towards scientific communication, and public education. Weather and climate are not the same. Weather relates to individual, and day-to-day changes in the atmosphere; climate is the statistical average of such changes. Weather is short-term, and of a chaotic nature, thus making it inherently unpredictable beyond a few days. Meanwhile, climate is long-term average weather, controlled by the composition of the atmosphere, and is thus more predictable on the time-scales considered.  A simple analogy is provided at the Climate Communication website,

While it is impossible to predict the age at which any particular man will die, we can say with high confidence that the average age of death for men in industrialized countries is about 75. The individual is analogous to weather, whereas the statistical average is analogous to climate.

Stepping beyond the individual, we encroach upon a global dialogue between, and within political and scientific institutions. While most scientists recognize the phenomenon that is global warming, there still remain a few who believe that there is nothing to be worried about. The latter argue that the Earth is more resistant to climate change than proposed. Many of the consequential changes are, in their opinion, not disastrous, and that cutting down the emission of greenhouse gases may result in economic damage far more potent than any of the effects of global warming.

The uncertainty that exists within the scientific community has been carried over to the political realm. Skeptics use it to argue for postponing action, while contenders point out that there are various other facets of life that require action in the face of uncertainty, such as buying health insurance. The IPCC has also pointed out that confronting a large-scale task such as climate change will not occur in an economic dissolution. As quoted from the 2014 report by the IPCC’s Working Group III,

Climate policy intersects with other societal goals, creating the possibility of co-benefits or adverse side effects. These intersections, if well-managed, can strengthen the basis for undertaking climate action.

Ultimately, what can we do about it? It isn’t possible to simply “stop” climate change. Even if we turned off every fuel-burning machine on Earth, the planet would warm at least another 0.5 degrees Celsius as the climate adjusts to the greenhouse gases that already have been emitted. Nevertheless, progressing toward the future, we can still make efforts in decreasing activities that may help propagate and positively reinforce global warming.

On a local level, we can do this basically by not using as much of the stuff that creates greenhouse gases as well as using less energy. Electricity governs much of the modern world, and much of the electricity that operates many of the devices in our homes comes from a power plant, which most likely burns fossil fuels to generate that power. The simple action of turning off lights when they are not in use, and using a fan or an air-conditions only when necessary can help. Similar initiatives can be taken in the view of using public transportation, efficient recycling and waste management, reforestation etc. Beyond all of this, we need to develop non-fossil fuel energy sources. Hydro-electric power, solar power, hydrogen engines, and fuel cells could help in this initiative towards a global change in energy sources.

In conclusion, much of this is easier said than done but that doesn’t mean we should give up. Given the global nature of the climate problem, we all have a hand in contributing to the solution, and in confronting the necessary alternatives and options we must also be willing to face agreements and disagreements in faith of positive communication. The real power to enact significant change rests in the hands of those who devise national and global policies. International and scientific collaboration on technology sharing, effective communication and education of the public supplemented by an efficient transition toward alternative, and green-energy initiatives would help make a difference in the long run.

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The environment’s role in our survival, and the importance of its preservation is common sense. There is nothing wrong in creating a better world. We have a moral responsibility in protecting and handing the planet over to the next generation. 

Climate Change – Part I – The Basics

Introduction

Climate change is a global issue that has wedded science to politics while simultaneously transcending the social responsibilities held by both institutions. A polarizing subject in many ways, climate change is considered as one of the most daunting challenges humanity currently faces; at its crux is an initiative towards global communication, and environmental responsibility.

To this day, there remains a schism between the public, and the scientific community when it comes to understanding climate change, and what it essentially means for our world. In a manner that follows the development of various other issues over the course of history, climate change highlights a certain measure of conflict in science, and ignorance.

Investing the time to learn the basics can prove the difference in being knowledgeable and informed or confused and manipulated. This is particularly crucial as climate change is a phenomenon that has wide implications to civilization, and overtly emphasizes the need for humanity to collaborate with each other in tackling the problem.

In this three-part series, we will address various facets of this issue ranging from the basics of the science behind the phenomenon as well as the consequential symptoms  or effects of climate change for the present, and the future. We will conclude by discussing the options that we must consider in our transition to achieve progress.

Let’s begin!

Dissecting Weather and Climate

Le’ts review the difference between weather, and climate. Simply, weather is local, and short-term while climate is long-term, and doesn’t relate to one single location. More precisely, the climate of an area defines the average weather conditions in the given region over a long period of time. The time period being considered generally involves changes taking place over tens of thousands of years. So, whenever we pass by a few winters that aren’t as cold as usual, it does not necessitate a change in climate. Such events are rather anomalies that don’t represent any long-term change.

Moving forward in our discussion, it is also imperative that we don’t underestimate the effects of small changes in climate. To put in perspective, the “Ice Age,” often talked about by scientists involved a world where the Earth’s average temperature was only 5 degrees Celsius cooler than modern day temperature averages. Small changes in climate can equate to major effects around the world. 

Climate Change or Global Warming

We often hear the phrases climate change, and global warming used interchangeably in describing climate transitions but there is a subtle difference. In the early 20th century, scientists used the term climate change when writing about events such as ice ages. But once scientists recognized the specific risks posed by human-produced greenhouse gases on the Earth’s climate, they needed a term to describe it.

Wallace Broecker’s paper in the journal Science, in 1975, entitled “Climate change: Are we on the brink of a pronounced global warming?” introduced the word global warming into the public lexicon.

Soon enough, the phrase global warming gained currency, and the term global change emerged as a way to describe all modes of large-scale impact on the planet, including issues such as the Antarctic ozone hole.

The planet as a whole is warming, but scientists prefer the term global change or global climate change. The reasoning behind this is that global warming can be interpreted as a uniform effect (warming everywhere on Earth), while a few regions may in fact cool slightly even if the planet were to warm up. In fact, it is a popular opinion that climate change sounds less frightening to the ear than global warming; the latter though catches more attention in the public eye. A few scientists, and activists also prefer to use global warming to imply human involvement in the process of describing climate transitions.

So, is the planet really warming up?

The short answer: YES! After laboriously working through a century’s worth of temperature records, various independent teams of scientists have converged on a rise of 0.8 degrees Celsius in the average surface air temperature of Earth when comparing the periods from 2003 – 2012 to 1850 – 1900. While this degree of warming may not sound like a big deal, it does make a big difference when it is in place everyday. Small changes can become amplified into bigger ones. Any warming can serve as a base from which heat waves can become worse. The effects are particularly pronounced in certain locations like the Arctic which has experienced an overall warming. Apart from the numbers, there’s a wealth of environmental evidence to bolster the case in favor of the Earth’s warming up. Without going too much into detail,

(1) Ice on land, and at sea has melted dramatically in many areas outside of interior Antarctica and Greenland.

(2) A lengthening of the growing season around much of the Northern Hemisphere.

(3) The migration of various forms of life, including mosquitoes, birds, and other creatures to higher altitudes, and latitudes due to the increasing warmth. Likewise, the migration of many forms of marine life moving poleward (the shift in ranges is 10 times the average for land-based species).

Other observations from the Intergovernmental Panel on Climate Change (IPCC) highlight the warming trend of the last 50 years being nearly the double of the last 100 years; a vast increase in ocean temperature to greater depths (the oceans absorb 80% of the heat of Earth’s climate system); increasing droughts; increased precipitation in eastern regions of the Americas, and northern regions of Europe, and Asia; drying trends in Africa, and the Mediterranean etc.

How Global Warming Works? 

Global warming is caused by an increase in the greenhouse effect. The greenhouse effect is not bad on its own, and is in fact a natural circumstance of the Earth’s atmosphere. It is also the reason why the Earth is warm enough for life to survive.

The greenhouse effect, in essence, involves a play of energy balance on the Earth’s. When sunlight reaches our planet, 30% of its gets reflected or scattered back to space by clouds, dust, or the Earth’s surface. More than 20% of the sunlight is absorbed in the atmosphere, mainly by clouds, and water vapor. Lastly, almost 50% is absorbed by the Earth’s surface including land, forests, pavement, oceans etc.

Now, all this energy doesn’t stay permanently on the Earth. If it did, the Earth would literally be on fire. In fact, the Earth’s oceans, and land masses re-radiate the heat, some of which makes it into space. Most of it though is absorbed by clouds, and greenhouse gases which in turn radiate the heat back to the surface, and some out to space. Since the heat doesn’t make it out through the Earth’s atmosphere, the planet becomes warmer. It is basically an energy imbalance scenario where there is more energy coming through the atmosphere, than that leaving the Earth.

The two main components of air include nitrogen (78%), and oxygen (20%) gas, both of which aren’t efficient in absorbing radiation from the Earth due to their two-atom structure. On the other hand, other gases with three or more atoms can capture energy far out of their scant presence. These are the greenhouse gases, the ones that keep Earth inhabitable. That’s all well, and good, but the same gases also warm the Earth. The more greenhouse gases we add to the atmosphere, the more our planet warms. The major players involved include: Carbon dioxide, Nitrous oxide,  Methane, and to a lesser extent, Water vapor.

 Greenhouse Gases: What’s Happening? 

The greenhouse effect is driven by naturally occurring substances in the atmosphere. This is predicated by a necessity for balance referring to the radiation cycles of the Earth mentioned earlier. Unfortunately, since the Industrial Revolution, humans have been pouring huge amounts of greenhouse gases into the atmosphere thus tipping the balance toward an amplified warming of the planet.

Carbon dioxide makes up less than 0.04% of the Earth’s atmosphere, most of which is due to early volcanic activity in the planet. Today, we are pumping huge amounts of the gas into the atmosphere as the gas is produced when fossil fuels are burned, as well as when people, and animals breathe, and when plants decompose. Extra carbon dioxide results in more energy absorption, and an overall increase in the Earth’s atmosphere. In fact, the average surface temperature of the Earth has gone from 14.5 degrees Celsius in 1860 to 15.3 degrees Celsius in 1980.

Nitrous oxide is another important green house gas, and while we don’t release great amounts of this gas through human activity, nitrous oxide absorbs much more energy than carbon dioxide. For example, the use of nitrogen fertilizer on crops releases nitrous oxide in great quantities.

Methane is a combustible gas, and the main component of natural gas. It also occurs naturally through organic material decomposition. Other man-made processes that produce methane include: extraction from coal, digestive gases in large livestock, bacteria in rice paddies, and garbage decomposition etc. Like its fellow compatriot greenhouse gases, methane also absorbs infrared energy, and keeps up the heat on Earth.

Apart from their devastating effects, it takes a long time for the planet to naturally recycle these various gases. For example, a typical molecule of carbon dioxide can stay airborne for more than a century. Thus, greenhouse gases have both a potent, and a long-standing impact on the Earth’s ecosystems. A few other gases that make up for the rest of the greenhouse players include the Chlorofluorocarbons (CFCs), water vapor, ozone etc. Water vapor is particularly interesting, as it isn’t a very strong greenhouse gas, but makes up for this in sheer abundance. As global temperatures rise, oceans, and lakes release more water vapor, up to 7% more for every degree Celsius of warming, which adds to the warming cycle.

What’s next? 

In conclusion, the mechanisms involved in climate change, or global warming, are largely positive feedbacks that amplify the warming of the planet: the evaporation of water from the oceans doubles the impact of carbon dioxide increase, and melting sea ice reduces the amount of sunlight reflected to space etc. While not all feedbacks are certain, it is a grounded truth that the planet has to constantly readjust to the changes we make in our environment, in the case of global warming, the consistent addition of greenhouse gases into the atmosphere. So far, I have laid the  basic groundwork for the symptoms we can expect to see, as a consequence of global warming, in our environment. Moving on in Part II, we will consider those changes in greater detail, and what they entail for the future of our planet.

Why Is Snow So Bright?!

If one wishes to experience the full spectrum of the annual cycle of the four seasons, Edmonton is certainly the place to visit. Though it varies every year, you can expect an early start to spring around March, with summer setting the pace in June, autumn settling in with September, followed closely by winter arriving around October at the earliest. Winter, in fact, is the chief minstrel of Edmonton’s seasonal ballad (Figure 1), with Boreas providing for the brittle winds, and dense snowfall that sweep across the city during this season.

Figure 1. Edmonton’s winter skyline

Who doesn’t like snow? I myself have never denied an opportunity to jump into or wade my way through a dense pools of snow (just make sure you are wearing the appropriate gear for the occasion), or on some occasions push others into them (my partner, Leina, in particular, could relate to a few “sweet” memories). In fact, it was only after arriving in Edmonton, 19 years old to boot, that I first saw snow in my life. This was back in 2009, and now that 2016 has come to an end, I have rounded off seven years to my predominantly snow-filled life in Edmonton, Alberta, Canada. Despite all of this, if there is one thing that I could never get used to in all these years, it would have to be waking up in the early hours of the day to the bright, and mildly annoying  pure, ambient white light emanating from the snow outside my apartment, leading now to the subject of our post, “Why Is Snow So Bright?”

The answer is quite simple. Snow has the highest albedo of any naturally occurring substance on Earth. Albedo is the percentage of reflectance (of light) off the surface of an object. Snow is ~ 90% reflective, which is why it is so damn bright. This begs the question of how a reflective surface may appear brighter than its diffuse illuminant (the sky, in this case). Having done a little bit of back-reading, it is reported,

“Three factors are largely responsible for this visually striking effect: the law of darkening for the cloud cover, the reflectivity of the snow and the average landscape albedo, and the observer’s contrast sensitivity function.”

 J.J. Koenderink, and W.A. Richards, Why is snow so bright?, J. Opt. Soc. Am. A, Vol. 9, No. 5, May 1992. 

We find that the explanation for the brightness of snow is a mixed physical, and psychophysical phenomenon. While the paper provided by J.J. Koenderink, and W.A. Richards go into great detail on the scientific methods that support these observations, I will provide a summary covering some of the interesting facts found in the paper. The three factors, aforementioned, are examined in a sequential manner, and the necessary conclusions derived accordingly.

The Scattering of Light

We begin with the law of darkening for the cloud cover. This involves intuitive observations we often make about the radiance or illuminance of the sky. The sky is not uniformly illuminated. This is quite noticeable depending on the elevation of our line of sight with respect to the horizon. Two factors are largely responsibly for the darkening that is usually observed from the maximum brightness we find at the zenith (point in the sky directly above us) to the grayish haze that we identify as the horizon:

“The angular distribution of the forward scattering (average differential scattering cross section) and the backreflectance to the clouds off the surface of the Earth.”

Light, or electromagnetic radiation, from the sun is scattered by particles in the atmosphere. This is commonly known as Rayleigh Scattering named after the British physicist Lord Rayleigh (Figure 2), a principle that describes the scattering of light by particles much smaller than the wavelength of the radiation.

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Figure 2. Lord Rayleigh

These particles can be individual atoms or molecules. The light from the sun is a mixture of all colors of the rainbow. Using a prism one can separate the “white” light from the sun to its different colors forming a spectrum (Figure 3). These colors are distinguished by their different wavelengths. Our vision is limited to what is known as the visible part of the spectrum ranging between red light at wavelengths of 720 nm to violet with a wavelength of 380 nm.

Figure 3. The visible spectrum (ROYGBIV)

In between, we have orange, yellow, green, blue, and indigo. The retina of the human eye has three different types of color receptors that are most sensitive to red, green, and blue wavelengths providing us the colored vision of our environment. On a clear cloudless day, we observe that the sky is blue. This is because molecules in the air scatter blue light from the sun more than they scatter red light. Meanwhile, at sunset we see the familiar red, and orange haze because the blue light from earlier has been scattered out, and away from our line of sight (Figure 4).

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Figure 4. Why is the sky blue?

Similarly, forward scattering is a subset of radiation scattering which involves changes in direction of less than 90 degrees. In contrast, the effect of the backreflectance of the surface of the Earth is found to be largely independent of the visual angle of observation as the clouds of an overcast sky are roughly Lambertian. No matter from what angle the observer views a Lambertian surface, the brightness of the surface apparently is the same. Unfinished wood is known to roughly exhibit Lambertian reflectance, while a glossy/coated wooden surface does not. These two factors, forward scattering and backreflectance, contribute to the radiance of the sky, and the observed darkening of the sky from the bright zenith to the grayish horizon.

What about our eyes?

From here onwards, it is smooth sailing. The paper discusses the last two major factors including the reflectivity of snow and the average landscape albedo, and the observer’s contrast sensitivity function. It is found that the albedo of snow typically ranges from 80% to 95% across the spectrum with lower values for higher snow densities. Though snow is not a true Lambertian surface, the approximation is satisfactory. The landscape albedo figures into much of the calculations involved, and we find that it is only in extreme situations that the radiance of the snow is equal to the radiance of the horizon sky. In general, a whiteout (Figure 5),  is only possible if the reflectance of the landscape is above 50% which rules out most effective natural landscapes with the exception of snow itself.

Figure 5. Whiteout, a weather condition where visibility and contrast is severely reduced by snow (or sand). As can be observed, the horizon disappears completely.

Much of what is demonstrated in the paper shows that the contrast effect of snow can cause the sky at the horizon to appear darker than the zenith sky. But, the zenith sky is still found to be brighter than the snow, so why is it that we are not able to recognize this difference, and identify that the sky is indeed brighter than the snow? The answer is once again quite simple. The sky at the horizon is darker than at the zenith owing to the law of darkening described earlier. This results in a gradient over the circular dome above us, but one that is so shallow that the gradient is generally not noticeable to the comparative resolution of our eyes, thus leading us to believe that the snow is in fact brighter than the sky that illuminates it.

References

  •  J.J. Koenderink, and W.A. Richards, Why is snow so bright?, J. Opt. Soc. Am. A, Vol. 9, No. 5, May 1992.