Arctic sea ice melting: the lighter blue areas are ponds, while the darker ones are open sea - Photo Credit: Wikipedia
Despite the fact that global warming and climate change are not the same, people out of the global scientific community often use both terms interchangeably. This is often employed as an awareness strategy by mass media outlets, as studies have shown that people are more responsive to “global warming” than they are to “climate change”. The main reason behind this is that the laypeope associate global warming to impending catastrophe, while climate change is relegated to natural shifts in weather. This may be fundamentally wrong, but it makes information regarding the topic much easier to assimilate. Also, upon further inspection of the effects of climate change and global warming, it is evident that they are so deeply related that talking about one of them necessarily encompasses talking about the other.
In a previous article, the effects of global warming were discussed in detail. What is interesting is that those same problems are listed in several official websites, including the one of the World Meteorological Organization, as the effects of climate change. The reason behind this is that global warming and climate change act like a matryoshka doll. Global warming causes climate change, which in turn causes sea level rise, risk of extinction for certain species, extreme droughts and downpours, as well as flashfloods, erosion and the disappearance of glaciers.
As the article on the effects of global warming treated all recent and current consequences of this issue, this article will focus on the projections for a future in which global warming and climate change have not been harnessed.
What is projected by organizations like the American Institute of Physics and the United States Environmental Protection Agency is more or less what is happening now, only worse. The effects of climate change that are being felt now are product of a 0.8°C raise in the global temperature over the last 100 years. According to the EPA, the global temperature is expected to at least double in the next century, increasing by 1.5°C if humans drastically lower their greenhouse gas emissions. In the worst of cases, the prospected global temperature is of nearly 6°C above today’s values, if mankind does not make the move from the toxic practices it is implementing right now to cleaner, sustainable ways of supporting itself. In perspective, a drop of just 5°C was enough to send North America into an Ice Age 20,000 years ago (NASA, W/D).
A map of predicted global warming at the end of the 21st century accourding to the HADCM3 climate model with a business-as-usual emissions scenario (IS92a). This model has an average warming of 3.0°C - Photo Credit: Wikipedia
But what exactly are the consequences? According to Nature.org, one fourth of the world’s species could be extinct or nearly extinct by 2050. But this is not new —after all, extinction is one of the all-time effects of climate change. The same Nature.org article mentions that climate change caused the Golden Toad of Central America to become extinct in 1999. For those with very short memory, the disappearance or the abysmal reduction of some species is something that is happening right now. Polar bears are becoming skinnier with the melting of the ice they depend upon and the coral reefs are being deprived of the algae they need to live by increasing sea temperatures.
The Golden Toad of Central America was the first species to become extinct due to climate change in 1999 - Photo Credit: Wikipedia
Among the effects of climate change that directly affect mankind is the rise in sea level. Throughout history, men have built cities in coastal areas, which could be submerged within the next century, the American Institute of Physics says. This belief is anchored in that 125,000 years ago, during the last interglacial age, global sea levels were at least 6.6 meters higher than today. This is especially relevant when taking into consideration that during that time, global temperatures were only 3-5°C higher than today (Kopp, 2009). The possibility of this rise in sea levels being gradual is very high, however, a sudden rise cannot be discarded.
The oceans also face the prospect of further acidification, which would endanger many marine species. Moreover, the bleaching in coral reefs is expected to increase from 30% to 50% if the amount of carbon dioxide in the atmosphere continues to grow.
Projected change in annual average preipitation for the 21st century, based on the SRES A1B emissions scenario and simulated by the GFDL CM2 - Photo Credit: Wikipedia
The Environmental Protection Agency contemplates in its key projections on weather that average annual precipitation is likely to increase towards the end of the century. Extreme weather events will become increasingly common, with dry places being affected by severe droughts and humid locations with the bulk of the precipitations. The API refers to this as an “intensified water cycle”. In addition to the effects of climate change mentioned above, tropical storms are bound to become more violent as winds become faster and precipitations in them increase in intensity. Several locations will endure more snow storms while the mountain glaciers and ice sheets face depletion, jeopardizing key water supply sources.
These maps show projected losses of sea ice in the Arctic and Antarctica. The maps in a) show the average ice concentration (the relative area covered by sea ice) from 1986-2005. The maps in b) and c) show climate model simulations of sea ice thickness in February and September near the end of the 21st century under low (b) and high (c) emission scenarios. In the Arctic, February is projected to have less ice (more blue); September is projected to be nearly ice-free (almost all blue). The projected changes in Antarctic sea ice are more subtle -Photo Credit: IPCC, 2013.
The melting will also be experienced by the Arctic sea and Greenland, with the first facing a 15% decrease in the annual extent of ice and a 25% decrease in the extent of ice at the end of the summer per every 1.1°C increase in the global temperature.
As said by the American Institute of Physics, the possibility for the effects of climate change to be reverted exists, but so does the possibility of them becoming worse. The API goes on to say that: “If emissions continue to rise for a century — whether because we fail to rein them in, or because we set off an unstoppable feedback loop in which the warming itself causes ever more greenhouse gases to be evaporated into the air — then the gases will reach a level that the Earth has not seen since tens of millions of years ago”.
In short, if the human race fails in reverting the harm it has done, the effects of climate change will be such that Earth will not exist as it is known today. The long-term effects of climate change could then encompass the very extinction of mankind.