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.
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.
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.