A press release from the World Meteorological Organization describes the global average temperature in 2015 as “likely to be the warmest on record and to reach the symbolic and significant milestone of 1° Celsius above the pre-industrial era”. The WMO also states that the years spanning 2011-2015 are bound to be the warmest five years in history and ascribes this to extreme weather and “human-induced global warming”.
Lake Powell at 42%, 2014 - Photo Credit: Flickr
This “extreme weather” encompasses an unusually strong El Niño in 2015, which led to a global coral bleaching event and below-average rainfall in countries across Central America, the Caribbean and Asia. The latter saw its opposite in the United States, Mexico and several South American countries, as well as Southeast Europe, Afghanistan and Pakistan, where instances of 24-hour totals exceeded normal monthly means. These unusual precipitation patterns caused severe drought in some countries and floods in others.
Other effects are the rise in ocean heat and sea level, as well as heatwaves and an increase in regional temperatures affecting South America, Eurasia, the west of North America and Africa. Tropical zones such as the Northwest Pacific, South Pacific and Northern Indian Ocean saw an exorbitant amount of cyclones, while there was a decrease in sea ice extent in the Artic. The opposite happened in Antarctica, where the daily maximum extent documented on the 6th of October was the 16th highest on record and the minimum extent (20th of February) was the 4th highest.
The World Meteorological Organization then goes on to say that anthropogenic (i.e. human-induced) climate change contributed to these events, especially those related to extreme high temperatures. In this, they are not alone. Cox et al (2000) say that “the continued increase of carbon dioxide concentrations due to anthropogenic emissions is predicted to lead to significant changes in climate” and Vitusek (1993) before them states that “there are a number of components of global environmental change of which we are certain ⎯certain that they are going on, and certain that they are human-caused”. In addition to them, the majority of scientists, both in and out of the climate field, believe that climate change is not only real, but greatly influenced by mankind.
But what exactly are men doing to cause and accelerate climate change?
THE ROLE OF MANKIND IN GLOBAL WARMING: GREENHOUSE EFFECT
According to Hardy (2003), mankind has changed the chemical composition of the atmosphere as a result of continuous deforestation and burning of fossil fuels ⎯coal, gas, and oil⎯ over the last century. Given the crucial nature of the atmosphere (particularly the troposphere layer) to the existence of life on Earth, it is safe to say that these changes have far-reaching consequences not only on climate, but in the ecosystems and all aspects of human life.
The reason why burning fossil fuels constitutes a hazard to the prevalence of life on Earth is the “anthropogenic emissions” (e.g. carbon dioxide, methane, ozone, nitrogen oxides, water vapor and chlorofluorocarbons) Cox et al mentioned in their study. These emissions, also called greenhouse gases, can be found as rare traces in the original composition of the atmosphere⎯which is mainly comprised of oxygen, nitrogen and argon⎯ but are also liberated to it as a byproduct of hydrocarbon combustion, thus altering said composition.
The greenhouse gases “influence the radiation balance or net heat balance of the Earth” (Hardy, 2003); in other words, these gases absorb energy which is then trapped in the atmosphere as heat (greenhouse effect), forming a blanket around Earth (NASA, W/D). This then causes global warming and therefore, climate change.
GLOBAL WARMING VS CLIMATE CHANGE
In the section above, a distinction was made between the terms “global warming” and “climate change”. This distinction is also found in scientific literature on the matter because global warming and climate change are not the same.
As defined by NASA, global warming is “the increase in Earth’s average surface temperature due to rising levels of greenhouse gases”, while climate change is “a long-term change in Earth’s climate, or of a region on Earth”. These definition are the ones used in scientific journals and there is an understanding that “global warming refers to surface temperature increases, while climate change includes global warming and everything else that increasing greenhouse gas amounts will affect”.
In fact, “climate change” was used long before Wallace Broker incorporated “global warming” to the scientific lingo in 1975. According to NASA, it was first coined as “inadvertent climate modification”, because although scientists acknowledged that human activities could potentially cause a climatic change, they were not sure if the global warming product of greenhouse gases would prevail over the cooling resulting from aerosol emissions or vice versa. It was then turned into “climate change” in the Charney Report ⎯the first decisive study of the National Academy of Science on the impact of carbon dioxide on climate⎯ and this term alongside “global warming” gained traction and became ingrained in the lingo of both the scientific community and the public at large.
There is, however, a difference in how the scientists use the terms in comparison to the general public. The former prefer using “climate change” because of it all-encompassing nature, while the latter largely prefer “global warming” and often use both terms interchangeably. This is confirmed in an article written by Time.com’s Bryan Walsh, in which he says:
“While the two terms are largely synonymous (…)’climate change’ has become the preferred term for scientists because it better describes the long-term changes in the planet’s climate (…)I simply rotate the two terms for variety’s sake.
But it turns out that global warming and climate change evoke very different reactions in ordinary Americans—and for those trying to motivate the public to act on greenhouse gas emissions, using ‘global warming’ could be more effective.”
Walsh then cites a study on gallup.com where a poll was conducted among several individuals, finding that although the response to both terms is similar to some extent, people are likely to be more concerned about “global warming” than “climate change”, as they associate the former to catastrophes and extreme events (melting sea ice, erratic precipitation patterns, rising sea levels) and the latter to normal weather patterns. Therefore, “global warming” elicits a more elevated sense of awareness in the current nature of this phenomenon and the role mankind plays on both causing it and impeding its progress, as well as the potential hazards the issues caused by global warming and climatic change represent to Earth as we know it.