Article 45: Last call of our astronomer – and of the international scientific consensus as well – this time about the shocking effects of (over-)population and (over-)consumption on the planet and the people.
The recent rapid increase in human population over the past three centuries – and especially over the last 70 years – has raised serious concern that the planet may not be able to sustain present or future numbers of inhabitants.
The 1993 InterAcademy Panel Statement on Population Growth – an international scientist consensus document, discussing and demanding a halt of the population expansion; the first worldwide joint statement of academies of sciences – stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming and pollution are aggravated by the population expansion.
According to the World Meteorology Organization, the years 2010, 2005 and 1998 ranked as the hottest on record and the ten warmest years on record have all occurred since 1998.
The human-induced greenhouse effect and global warming. Credit: WWF Australia
But raw numbers of people are only one factor in the effects of people. Their lifestyle, resulting in footprints, is equally important. The carbon footprint is one of the family of footprint indicators, which also includes the water footprint and the land footprint.
The water footprint of an individual, a community or a business, is defined as the total volume of freshwater used to produce the goods and services consumed by the individual or community or produced by the business.
The land footprint is a consumption-based indicator, i.e. it looks at the resources needed to create a final product, or by an organization or a country, wherever they are in the world.
For example, cows will require land to graze on within a country, but may also be fed by feed grown on land in another country.
National carbon dioxide (CO2) emissions per capita. Source: World Bank
A carbon footprint is the measure of the amount of greenhouse gases – measured in units of carbon dioxide – produced by human activities. A carbon footprint can be measured for an individual or an organization, and is typically given in tons of CO2-equivalent (CO2-eq) per year. For example, the average North American generates about 20 tons of CO2-eq each year. The global average carbon footprint is about 4 tons of CO2-eq per year.
An individual’s or organization’s carbon footprint can be broken down into primary and secondary footprints. The primary footprint is the sum of direct emissions of greenhouse gases from the burning of fossil fuels for energy consumption and transportation. More fuel-efficient cars have a smaller primary footprint, as do energy-efficient light bulbs in your home or office. Worldwide, 82% of anthropogenic greenhouse gas emissions are in the form of CO2 from fossil fuel combustion. The secondary footprint is the sum of indirect emissions of greenhouse gases during the lifecycle of products used by an individual or organization.
For example, the greenhouse gases emitted during the production of plastic for water bottles, as well as the energy used to transport the water, contribute to the secondary carbon footprint. Products with more packaging will generally have a larger secondary footprint than products with a minimal amount of packaging. An individual’s carbon footprint is the direct effect his/her actions have on the environment in terms of greenhouse gas emissions. In general, the biggest contributors to the carbon footprints of individuals in industrialized nations are transportation and household electricity use. An individual’s secondary carbon footprint is dominated by their diet, clothes and personal products.
Source: Maggie L. Walser, Carbon Footprint
Worldwide, the fossil fuels used for transportation contribute to over 13% of greenhouse gas emissions. In the U.S.A., 20% of greenhouse gas emissions come from home energy use. Worldwide, agriculture contributes to nearly 14% of total greenhouse gas emissions.
The three primary greenhouse gases in the Earth’s atmosphere are carbon dioxide, methane and ozone. Without greenhouse gases, the average temperature of Earth’s surface would be about – 18 C (0°F), colder than the present average of 14°C (57°F). But since the beginning of the Industrial Revolution (taken as the year 1750), human activities have produced a 40% increase in the atmospheric concentration of carbon dioxide, from 280 parts per million (ppm) in 1750 to 400 ppm in 2015. Anthropogenic carbon dioxide (CO2) emissions (i.e. emissions produced by human activities) come from combustion of carbon-based fuels, principally coal, oil and natural gas, along with deforestation.
In 2008 The New York Times stated that the inhabitants of the developed nations of the world consume resources like coal and oil at a rate almost 32 times greater than those of the developing world, who make up the majority of the human population.
Seven of these indicators would be expected to increase in a warming world and observations show that they are, in fact, increasing. Three would be expected to decrease and they are, in fact, decreasing. Credit: US National Oceanic and Atmospheric Administration – National Climatic Data Center
Credit: Down to Earth Climate Change
For the planet, 2015 was more than a full degree Celsius (1.8°F) warmer than temperatures in 1880, when consistent record-keeping began – according to scientists from NASA and the National Oceanic and Atmospheric Administration, who released their analyses together, but independently of one another, on January 20, 2016. The scientific opinion on climate change is the overall judgment among scientists regarding whether global warming is occurring, and (if so) its causes and probable consequences. The scientific consensus is that the Earth’s climate system is unequivocally warming and that it is extremely likely – meaning, of at least 95% probability or higher – that humans are causing most of it through activities that increase concentrations of greenhouse gases in the atmosphere, such as deforestation and burning fossil fuels, causing most of the rise in temperatures since 1950. No doubt, life on Earth has survived large climate changes in the past and extinctions and major redistribution of species have been associated with many of them.
But now it is different: now we are here and now we are one of the species threatened! Now we are living in coastal cities in danger of a rise in sea level, now we are living on land increasingly too dry or too wet and in societies under the pressure of human migration on a large scale. This time there will be humans hanging around, in great numbers, and we are those humans. This time global warming will affect us! We ourselves will see…
- more extreme weather and changes in the amount, intensity, frequency and type of precipitation
- Arctic sea ice extent declining, a widespread retreat of alpine glaciers and reduced snow cover in the Northern Hemisphere
- sea levels rising
- the ocean surface warming
- large-scale changes in ocean circulation
- ocean acidification
- a smaller amount of oxygen in the oceans, with adverse consequences for ocean life
- with a global average temperature increase of 1–4 °C (relative to the temperatures over the years 1990–2000), at least a partial deglaciation of the Greenland ice sheet and possibly of the West Antarctic ice sheets, contributing 4 to 6 meters (13 to 20 ft) or more to sea level rise
- changes of the Atlantic Meridional Overturning Circulation (AMOC), an important component of the Earth’s climate system, characterized by a northward flow of warm, salty water in the upper layers of the Atlantic and a southward flow of colder water in the deep Atlantic, resulting in reduced warming or (in the case of abrupt change) absolute cooling of northern high-latitude areas near Greenland and North-Western Europe, an increased warming of Southern Hemisphere high-latitudes, tropical drying, as well as changes to marine ecosystems, terrestrial vegetation and oceanic CO2 uptake
- impact on sectors sensitive to climate change, including water resources, coastal zones, human settlements and human health
- impact on industries sensitive to climate change
- impact on agriculture and food production around the world
- an increase in the number of people at risk of hunger, compared with reference scenarios with no climate change
- wetter coasts, drier mid-continent areas and further sea level rise, resulting in human migration: millions of people being displaced by shoreline erosions, river and coastal flooding, severe drought or loss of access to resources (e.g., water resources)
- human migration becoming a source of political or even military conflict
- global economic losses and rapidly rising costs
- biodiversity loss in cool conifer forests, savannas, Mediterranean-climate systems, tropical forests, in the Arctic tundra and in coral reefs
- physical, ecological and social systems responding in an abrupt, non-linear or irregular way to climate change…
Huge amounts of methane are stored around the world in the sea floor in the form of solid methane hydrates. Climate warming, however, could cause the hydrates to destabilize. The methane, a potent greenhouse gas, would escape into the atmosphere and could even accelerate climate change. The future warming of methane deposits may release more methane to the atmosphere, creating more global warming.
This cycle could repeat itself many times.
Image Source: Michael Pidwirny
To summarize this catastrophic scenario:
Source: A student’s guide to global climate change
And even now you haven’t seen yet all the bad news!
Apart from global warming and its consequences, over-population and over-consumption are the roots of other problems too.
We are watching them already and we may see increasingly…
- depletion of natural resources, especially fossil fuels
- increased levels of air pollution, water pollution, soil pollution and noise pollution
- deforestation and loss of ecosystems that valuably contribute to the global atmospheric oxygen and carbon dioxide balance
- loss of arable land and increase in desertification
- farming abroad
- loss of cropland to development and industry
- cars and people competing for crops
- mass species extinctions from reduced habitat in tropical forests due to slash-and-burn techniques that sometimes are practiced by shifting cultivators, especially in countries with rapidly expanding rural populations
- high infant and child mortality, associated with poverty
- intensive factory farming to support large populations, resulting in human threats, including the evolution and spread of antibiotic resistant bacteria diseases, excessive air and water pollution, and new viruses that infect humans
- increased chance of the emergence of new epidemics and pandemics
- for many environmental and social reasons, including overcrowded living conditions, malnutrition and inadequate, inaccessible or non-existent health care, the poor are more likely to be exposed to starvation, malnutrition or poor diet with ill health and diet-deficiency diseases (e.g. rickets)
- unhygienic living conditions for many, based upon inadequate fresh water, water resource depletion, discharge of raw sewage and solid waste disposal
- if melting continues at current rates, rivers like the Yellow River, Yangtze River, the Ganges and the Indus could become seasonal, causing wheat and rice harvests to plummet
- conflict over scarce resources and crowding, leading to increased levels of warfare
- rapidly growing populations, rising hunger and poverty, resource depletion and political stresses, pushing more countries such as Afghanistan, Haiti and Sudan toward state failure each year, decreasing stability…
David Attenborough described the level of human population as a multiplier of all other environmental problems.
A study by the United Nations Environment Program (UNEP), which involved 1400 scientists and took five years to prepare, found “that human consumption had far outstripped available resources: each person on Earth now requires a third more land to supply his or her needs than the planet can supply.”
Earthrise, December 24, 1986. Credit to astronaut Bill Anders, NASA
But my dear Earthling, how many Earths do you see rising?”
Thanks to Wikipedia, the free encyclopedia, for the postings of the Common heritage of mankind, Human overpopulation, the Effects of global warming and the Scientific opinion on climate change; to the Yearbooks of the Worldwatch Institute, to Maggie L. Walser for ‘Carbon footprint’, published in the Encyclopedia of Earth, and to Down to Earth Climate Change.