Global warming is a problem that seems complicated to understand:
- It is impalpable, unlike the threats to which our human brain is accustomed to reacting.
- It may seem distant, both geographically (we often speak of ice melting at the poles), or temporally (dates are often medium-term: 2030, 2050, even long-term: 2100 …)
- It is either anxiety-provoking or ignored, since we do not know exactly what its future intensity will be or its exact consequences
Except that global warming is, despite non-believers, already here and its potential impacts in terms of disruption (floods, droughts, heatwaves…) are devastating. But there is some good news:
- Our actions today have an impact on the climate of tomorrow. We still have room to move things in the right direction.
- Nature is resilient: if given the opportunity, Nature can reconstruct what man has destroyed. For example, plants have recently been found to adapt by becoming more efficient in their use of water under high carbon dioxide concentrations.
This does not mean that the game is won; for Nature to do its job, we must give it a chance. And so act today.
What is global warming?
Before we delve into the causes and consequences of global warming, we need to take the time to define what the term actually means.
- Simple definition of global warming
Global warming is a global phenomenon of climate change characterized by a general increase in average temperatures (particularly related to human activities), which modifies on the longterm weather balances and the ecosystems.
When we talk about global warming today, it is the phenomenon of temperature increase that has been occurring on Earth for 100 to 150 years. Since the beginning of the Industrial Revolution, average temperatures on earth have increased more or less regularly. In 2016, the average temperature on the planet earth was about 1 to 1.5 degrees above the average temperatures of the pre-industrial era (before 1850).
- Scientific definition of global warming
More precisely, when we talk about global warming, we are talking about the increase in temperatures linked to industrial activity and in particular to the greenhouse effect: we therefore sometimes speak of anthropogenic (Of human origin) global warming. It is therefore a form of global warming whose causes are not natural but economic and industrial.
Many scientists are studying this phenomenon and trying to understand how the activities of human societies cause this warming. These scientists are grouped together in the IPCC (International Group of Experts on Climate), and they regularly publish reports studying the evolution of global warming.
The causes of global warming
Over the last 200 years, the Industrial Revolution has one of the most drastic changes in human societies. For our economic and industrial activities, we have developed machines and technologies around the world that need energy to function. To produce this energy, we have used different energy sources such as wood, coal, then oil, gas… And by burning all these resources to produce energy, we have emitted into the atmosphere more and more greenhouse gases and especially CO2, carbon dioxide.
As a result, the usual atmospheric balance was disturbed and the greenhouse effect amplified. As a result, the climate is warming and today we are measuring average temperatures of almost 1 degree above pre-industrial temperatures (ie the temperatures of the beginning of the 19th century).
What is the greenhouse effect?
The first assumptions about the greenhouse effect were made by scientist Jacques Fourier in 1824. Several scientists after him have studied study and tried to quantify the phenomenon, as Claude Pouillet and John Tyndall. But the first experiment of precise validation and quantification of the greenhouse effect was done by the scientist Svante Arrhenius at the end of the 19th century.
In the 1890s, Arrhenius discovered that an air rich in carbon dioxide retains more heat from solar radiation, which leads to an increase in the temperature of the air. He concludes that if large quantities of carbon are released into the atmosphere (because of industrial activities that burn coal), the air will be charged with CO2 and retain more heat. The first estimates of the temperature increase made by Arrhenius or other scientists of the time, such as geologist Thomas Chamberlin, are as follows: if we double the amount of greenhouse gases in the atmosphere, the temperature average will increase by 5 degrees. In 1901, Gustaf Ekholm uses for the first time the term “greenhouse effect” to describe the phenomenon.
For decades, these discoveries have not been taken seriously in the scientific community. At the time, many experts believe that nature could self-regulate and that the impact of man was minimal. Notably, many scientists thought that the excess CO2 would be absorbed by the ocean anyway, which is true, but not totally.
However, the thesis of the possibility of global warming linked to greenhouse gases (including carbon dioxide) was finally validated in the 1940s by Gilbert Plass. Using modern technologies, he provided definitive evidence that the concentration of greenhouse gases in the atmosphere affects the ability of the air to retain infrared radiation and heat. These were the first definitions of global warming.
In the graph above, we see a clear acceleration after 1950 (after the Second World War) of CO2 emissions, and an acceleration even more spectacular since 2005. In 2016, CO2 emissions were 23 times those of 1950. The result? A concentration of CO2 in the atmosphere that had not been reached for millions of years on Earth (when the sea level was a few tens of meters above their current level).
Global sources of greenhouse gas (GHG) emissions, according to the IPCC, are broken down as follows:
- 25% comes from “agriculture, forestry and other land uses
- 6.4% to buildings
- 14% to the transport sector
- 21% to industry
- 9.6% to “other energies”
- 26% due to indirect CO2 emissions, via electricity and heat production. Of these 26%:
- 1.4% are related to electricity and heat production related to the energy sector
- 11% to electricity and heat production related to the Industry sector
- 0.3 to electricity and heat production related to the transport sector
- 12% to electricity and heat production related to buildings
- 0.87% to electricity and heat production related to agriculture, forestry and other land uses
The consequences of global warming
Experts predict that the ongoing climate change resulting from human activities will have some positive consequences, such as the discovery of new energy resources or the development of tourism in some parts of the world. But overall, the impacts of global warming should rather be negative.
Depending on the different climate models, the effects of warming will be very diverse and geographically unequal. But the global warming of the planet by the increase of the greenhouse effect should modify the major climatic mechanisms such as average temperature levels, oceanic and atmospheric circulations, the water cycle, etc.
Several possible consequences of these climate changes are the subject of scientific consensus. Some have already been observed.
Melting ice and permafrost (or permafrost) is expected to open up access to new arable land, new mineral and energy resources, and new shipping routes. In 2016, the Arctic sea ice recorded record fonts.
This melting ice will also cause ocean levels to rise, flooding areas of very low altitudes and altering coastal geography. Over the last 50 years, the ocean level has risen by about 10 centimeters. And Nasa estimates that in 100 to 200 years, it will rise again by at least one meter. The UN, for its part, provides that between 10 and 20,000 islands could be removed from the map.
The amplification of evaporation and precipitation phenomena and the disruption of jet streams – these huge high-altitude currents – are all factors that are already increasing the frequency and intensity of droughts – such as the California drought in 2016 – and floods.
Shifting ranges of organisms and diseases, and therefore large agricultural areas, would result in the disappearance of species and ecosystems and a transformation of landscapes. Thus, in 2016 and 2017, the Great Barrier Reef, a treasure of biodiversity inscribed on the World Heritage List, experienced two consecutive years of record bleaching (1,500 km out of 2,300 affected in 2017). And according to a US study, one in six animal species could be extinct. A threat that would vary according to the regions of the world. 23% of the species would be threatened in South America against 14% in Australia and New Zealand.
The planet could see an increase in frequency and intensity of extreme weather events (storms, torrential rains, etc.).
All of these changes in the environment will probably have a profound impact on human societies.
Agricultural and fisheries production will be affected as will water resources. Consequences, according to the Food Bank and the UN: more than 100 million people could fall into extreme poverty and nearly 600 million could suffer from malnutrition by 2080.
Territorial security and infrastructure should also be affected.
The health consequences of climate change could also be important. A warming of 2 to 3 °C would be enough to increase by 5% the number of inhabitants exposed to malaria. And by 2080, WHO estimates that two billion more people may be at risk of dengue transmission. Diarrheal diseases – resulting from water contamination – could increase by 10% in the next 15 years.
The consequences of these upheavals should therefore be reflected in the increasing number of climate refugees and the increase in geopolitical instability. Already the people of Bikini Atoll in the Pacific have sought asylum in the United States. And the Internally Displacement Monitoring Center counted some 83.5 million climate refugees between 2011 and 2014 while the UN predicts they will be 250 million by 2050.
Finally, in 2007, the economist Nicolas Stern estimated the economic cost induced by global warming between 1% and 10% of world GDP in 2100, or 6000 billion dollars.
What you can do to help
- Quantify our actions
Quantifying our actions makes it possible to know the impact of one act compared to another in terms of GHG emissions. It is therefore essential to learn about the carbon footprint of each of our actions.
As seen previously, global warming is due to greenhouse gases released into the atmosphere. In order to respect the objectives of the Paris agreement, we must limit to 2 tonnes our amount of CO2 emitted per year and per inhabitant.
- State reduction of greenhouse gas emissions
States have the power to impose standards, to force individuals and companies to limit their CO2 emissions. Aware of the stakes, the representatives of the different countries of the world have been meeting regularly in the form of COP for more than 20 years. But so far, no binding agreement has been signed.
However, given the figures seen above, the action is clearly not yet satisfactory because it produces almost no effect: emissions to greenhouse gases continue to increase.
- Reduction of greenhouse gas emissions at the individual level
To act oneself, on one’s own scale (and to become a model for others). Yes it is possible, and it is even desirable, in the face of the inertia of the political powers.
“Leading by example is not the best way to convince … it’s the only one” (Mahatma Gandhi)
There are many ways to act. The first being in one’s consumption behavior. We must be aware that every act we do has an impact. And this impact, although impalpable, does exist.
In addition, good reflexes are needed; do not overheat (even cover yourself a little more at home), reduce the thermostat at night, and happen as much as possible air conditioning, which is a disaster for the climate.
- Buy and eat less meat
While this gesture may seem trivial, and completely disconnected from global warming, it actually has a concrete and important impact on global warming. Indeed, to obtain meat you need:
- an animal
- vegetable proteins to feed it
- water to give it to drink
What interests us here are the vegetable proteins that we give it. Each animal, to grow, requires huge areas devoted to crops. And these surfaces are created at the expense of the forest. The forest is the most important terrestrial carbon reservoir. It sequesters 9.2 Gt of net CO2 emissions per year, equivalent to one third of global greenhouse gas (GHG) emissions.
On the following chart (FAO source, published in a report funded by the European Commission), you can see that more than half of the “imported deforestation” (ie the products that contribute to the destruction of the three large tropical forest basins of the world) are used for soybeans, which are mainly used for the production of animal feed, animals intended for… meat production.
Not only does deforestation decrease GHG storage capacity, but it also results in GHG emissions through the combustion and decomposition of organic matter. These gross emissions represent about 11% of the world’s annual anthropogenic GHG sources.
- Fight against deforestation!
Some labels guarantee sustainable forest management. By purchasing products (paper, furniture, etc.) bearing the Forest Stewardship Council (FSC) label or the European Certified Forest Program label (PEFC), we can contribute to the preservation of forests and thus limit anthropogenic GHG emissions.
- Preserve the oceans!
To fight climate change, we must preserve the oceans. For this, each of us can act on a daily basis. For example, we can buy environmentally friendly household products to avoid dumping polluting chemicals into the oceans.
- Consume clean energy!
To reduce our impact on climate change, we can choose clean energy from renewable resources. More and more energy suppliers and good manufacturers are encouraging their development: let’s promote them as soon as possible to reduce our daily GHG emissions.
- Reduce your energy consumption!
An energy label classifies products according to their energy consumption. This classification is symbolized by a letter. The most energy efficient and therefore the most respectful of the planet are classified A +, A ++ and even A +++! For example, a device rated A ++ consumes 45% less energy than a device rated A.
- Sort out your trash!
The best waste is the one we do not produce! For that, many solutions exist: we can avoid buying products made with non-degradable material. However, it’s hard to say that we could overall stop using certain products altogether. Thus, make sure that you recycle everything that can be recycled.
- Promote what is known as the circular economy!
We can scale our consumption patterns to combat global warming. Based on the 3Rs principle: Reduce, Reuse and Recycle we can significantly reduce our waste quantities and avoid unnecessary production of new objects. Furniture, textiles or home appliances, all our everyday consumer products can be repaired or find new life through recycling.
- Use soft modes of transport!
Using public transit, electric vehicles or carpooling is an effective way to reduce our greenhouse gas emissions when we travel. The best solutions obviously remain cycling and walking, both ecological, economical and good for health. Moreover, a survey by the ADEME reveals that half of the trips by car are less than 3 km, a perfectly calibrated distance for cycling and walking.
Since 2006, the Action Carbone Solidaire program of the GoodPlanet Foundation’s mission is to fight against global warming by developing sustainable and economically viable alternatives to polluting activities, for the benefit of the most disadvantaged populations. By supporting these voluntary carbon offset projects, we can all contribute to the fight against climate change.