By Gabriel Andre – Art in Tanzania internship
What are the main consequences of climate change and the risks to our survival?
The first consequence of climate change is the rise in temperature, accompanied by the harmful effects of heat on biodiversity. But why do we keep hearing that we must not exceed the “2 degrees more” of the Paris Agreement by 2100?
Temperature rise and disruption of the water cycle
Source
Indeed, the storage capacity of water in the atmosphere varies according to its temperature. As the temperature increases, the storage capacity increases. As the temperature rises, evaporation is prevalent, and the amount of water stored as water vapour increases. As a result, rainfall is more abundant, and there is an increase in the frequency and intensity of heavy precipitation events (especially in mid-latitudes and humid tropics). Warmer air can also contain more water vapour, intensifying extreme phenomena such as cyclones, hurricanes, and typhoons. There is no need to recall the human tragedies caused by hurricanes Sandy (2012), Irma (2017) or Hurricane Harvey (2017).
Melting ice zones
Global warming leads to melting ice zones (glaciers, ice caps, ice packs) with different consequences. Melting glaciers impact freshwater reserves because by melting too quickly, they no longer fulfil their role as reservoirs that gradually release freshwater at steady intervals. Freshwater is drinkable and is a vital necessity for animals and humans daily. Today, water demand exceeds the available quantity, which is already a major geopolitical issue in many dry regions worldwide. Additionally, the melting of these glaciers releases freshwater, which then flows into rivers, seas, and oceans, causing water levels to rise. The melting of the ice sheets, vast areas of ice resting on land whose height can reach several thousand meters, would be devastating if they were to melt entirely.
On our planet, there are only two ice sheets:
- The northern part of Greenland, which has existed for 3 million years
- The southern part of Antarctica is the largest and has existed for 30 million years. Given the thousands of meters of thickness of the ice sheets, their complete melting would raise the sea level by 7 meters for Greenland and 54 meters for Antarctica, consequently causing the disappearance of many islands (such as the Maldives) and the relocation of a large part of the coastal population.
Our forests are dying
As we have seen with the carbon cycle, forests play a crucial role in sequestering carbon today. As a living matter, the flora is composed of carbon, and thanks to photosynthesis, it absorbs atmospheric CO₂ to transform it into oxygen. Conversely, when the forest dies, or in the event of deforestation, the decomposition of plants leads to the emission of CO₂. The same is true when fires ravage forests: combustion releases all the CO₂ that is then stored and stabilized into the atmosphere.
With climate change, we are witnessing:
- a warming of the air and soil temperature, destabilizing ecosystems and biodiversity,
- periods of drought and flooding that can deplete soils and kill the biosphere,
- a significant increase in the frequency and intensity of fire outbreaks.
These three phenomena, which are consequences of climate change, lead to the decline of plants. Those that survive will have a poorer capacity to absorb CO₂, and those that die will decompose, releasing CO₂. Thus, the concentration of GHGs in the atmosphere increases, fueling global warming, which in turn exacerbates the three causes listed above. We are not talking about a hypothetical situation, such as the Australian forests going up in smoke in the summer of 2019, and President Bolsonaro’s efforts to deforest the Amazon as quickly as possible. In opposition to pressure from European countries to act to slow the fires in the Amazon, the latter said, “Brazil owes no debt to the planet in terms of environmental preservation”, he said during a conference in Santiago, Chile, on May 23rd of 2019.
The two climate time bombs
Thawing permafrost
Permafrost refers to permanently frozen ground, i.e., at a temperature that has never been above 0 for at least two years. Permafrost is found on about 20% of the planet’s surface, notably in Greenland, Alaska, Canada and Russia. It is even found in France, in the Alps.
The massive problem with permafrost is that it contains elements that have been locked in the ice for thousands of years. To take an image, permafrost is like a giant freezer. If you leave the freezer door open, your pizza thaws, your ice cream melts, and microbes feed on these organic elements. Similarly, as the permafrost melts, it releases organic matte,r which, when subjected to the activity of microbes, produces CO₂ in the presence of oxygen or methane in an oxygen-free environment. These GHGs would then enter the atmosphere, accelerating global warming.
The potential for releasing GHGs from permafrost is colossal: we are talking about 1500 Gt, i.e., twice the amount of GHGs already in the atmosphere. This would triple the concentration! Just imagine the additional greenhouse effect that would be generated. In this sense, melting a large part of the permafrost constitutes one of the two “climate bombs” from which it would probably be impossible to recover. Another necessary consequence is that permafrost also contains diseases that have been dormant for hundreds or thousands of years. If the permafrost melts, it could release them and create significant health crises.
For example, in 2016, an Anthrax outbreak killed several humans and over 2,300 reindeer in Siberia. The disease had disappeared for more than 75 years in the region.
It reappeared with the melting of permafrost, which kept the corpse of reindeer that had died of the disease (and thus its deadly bacteria) frozen. Anthrax can be treated with antibiotics; however, this is not necessarily the case for all other viruses for which we do not have a cure or effective treatment. The risk of epidemics or disease outbreaks is very high. The risk of epidemics or pandemics is significantly worse than that of COVID-19 and is also a very real consequence of climate change.
Methane Hydrate
Another potential ‘climate bomb’ is methane hydrate. These are methane molecules trapped in ice. They are found in large quantities:
- Under permafrost
- At the bottom of the oceans, in ocean sediments.
For now, this methane is stored in these reservoirs. It isn’t easy to estimate the exact quantities, but we are talking about 10,000 Gt, which is seven times more than all the GHGs contained in the permafrost and, therefore, 21 times more than all the GHGs currently present in the atmosphere!
Unfortunately, these molecules could become unstable if current warming exceeds the famous 2-degree mark. As the permafrost melts or the oceans warm, methane hydrate will come into contact with higher temperatures. The unstable probability of these molecules becomes significant with a 2-degree rise in temperature. In this case, the molecules can dissociate, and the methane can escape directly into the atmosphere. Given the vast volume of methane we are talking about, it is easy to understand the devastating consequences of global warming and its impact on life on Earth.
There are many other devastating effects caused by global warming, such as the acidification of our oceans, possibly causing the disappearance of its aquatic fauna and flora; modified ocean currents, reducing the capture of CO2; or the Albedo effect, which is the mechanism of absorption and reflection of light energy that will be less and less effective because of the ice melting. Therefore, we understand that it is imperative to act quickly for our survival and avoid scenarios such as the melting of the permafrost or islands like the Maldives, which are being buried by the rising waters. As climate scientist and Nobel Peace Prize winner Jean Jouzel says, “Global warming, as it would be if nothing is done, is another world.” It is a world where, according to the UN, there will be at least 150 million climate refugees. It is a world where southern Europe would resemble the Sahara, with temperatures approaching 50 degrees in the summer in France. It is a world where by 2070, 1 billion people will be living in areas where, almost every day of the year, outdoor conditions will be lethal.
But suppose a country like France would be like the Sahara in the summer. What can a country like Tanzania, which already experiences temperatures of over 40 degrees from November to March, expect? How would global warming impact a population where more than 80% of the people live only in agriculture and depend on the climate?
