welcome to the sixth great mass extinction
By zteve t evans
Over the last 450,000, 000 years the Earth has gone through periods when up to 90% of life on the planet has perished in mass extinctions. Looking back over such great distances in time makes it difficult for humans to comprehend what happens with mass extinctions. All we really have is the fossil record, geology, and other sciences to help us understand what happened, by looking at what remains today. Now for the first time humans can experience at first hand what happens as a mass extinction event unfolds.
Does that sound interesting, fascinating and exciting? For the first time we can scientifically observe, record and chart the progress of this event as it happens, because it is happening in the here and now.
But wait a minute! if it is happening now doesn't that mean we are a part of it ? Yes it does, and if we are lucky humans just might survive as one of the few remaining species, but do not count on it.
Does that sound interesting, fascinating and exciting? For the first time we can scientifically observe, record and chart the progress of this event as it happens, because it is happening in the here and now.
But wait a minute! if it is happening now doesn't that mean we are a part of it ? Yes it does, and if we are lucky humans just might survive as one of the few remaining species, but do not count on it.
Disappearing biodiversity
Humans do not know for sure how many species of fauna and flora we share the planet with but it is known to be millions. Although there are about 2 million species known to science it is estimated that there could be 5 to 15 million but could be as much as 100 million species altogether. Clearly there is a huge gap in our knowledge. Nevertheless it does show there is great biodiversity of life on the planet which biologists believe to be essential to maintain a healthy environment for all living organisms.
Some of these like bacteria and spores we can only see with a microscope. Many of the larger ones we see, we interact with them, we can count and study them and of course there are the ones we like, the cuddly, cute funny ones and the one that taste good. We have learned how to breed and domesticate animals and plants and keep them in such numbers that they seem safe from any threat of extinction. For example, cattle, sheep and chickens do not appear to be in danger of extinction as we breed them in their millions, but their existence depends on us. Nevertheless, the situation for many wild species of flora and fauna in the wild is becoming increasingly desperate.
Humans do not know for sure how many species of fauna and flora we share the planet with but it is known to be millions. Although there are about 2 million species known to science it is estimated that there could be 5 to 15 million but could be as much as 100 million species altogether. Clearly there is a huge gap in our knowledge. Nevertheless it does show there is great biodiversity of life on the planet which biologists believe to be essential to maintain a healthy environment for all living organisms.
Some of these like bacteria and spores we can only see with a microscope. Many of the larger ones we see, we interact with them, we can count and study them and of course there are the ones we like, the cuddly, cute funny ones and the one that taste good. We have learned how to breed and domesticate animals and plants and keep them in such numbers that they seem safe from any threat of extinction. For example, cattle, sheep and chickens do not appear to be in danger of extinction as we breed them in their millions, but their existence depends on us. Nevertheless, the situation for many wild species of flora and fauna in the wild is becoming increasingly desperate.
No species lasts forever!
The golden rule of terrestrial biology seems to be that no species lasts forever. In the distant past the Earth has gone through five major mass extinction events. The first of these was the Ordovician-Silurian mass extinction around 350,000,000 years ago and the last was the Cretaceous-Palaeogene mass extinction about 65,000,000 years ago.
The causes of these mass extinction events varies, but includes volcanism, climate change, gamma ray bursts from sunspot activity, an asteroid strike in the Cretaceous-Palaeogene period that led to the dinosaurs being killed off and other calamities. It is often the case where one cause triggers another such as when an asteroid struck the Earth at the end of the Cretaceous Period which caused dust to accumulate in the atmosphere blocking out the sun.
The number of species of flora and fauna under threat globally is rising. Mammals make up a quarter of this figure. This time it cannot be blamed on a rogue asteroid. The cause lies directly with human activity that is causing global warming, contamination of the seas, pollution of the atmosphere, mass deforestation and the wanton killing of species for pleasure and profit and more besides. If a rogue asteroid does strike it will add to the destruction and perhaps speed up the process of mass extinction which has already underway.
The loss of species
The WWF say the 23% or about 1,130 species of mammal and 12% of birds, about 1,195 species, are threatened. Over the last 500 years alone there has been reduction in the populations of 25% in all known species over the last 500 years that can be attributed to human activity. Not all groups of species have been affected equally. Around a third of all vertebrate species are believed to be threatened. Of the vertebrates the amphibians have been hit hard, with about 41% struggling for survival, while 17% of birds are affected up till now.
The degree to which insect species are affected varies across species. Butterflies are beginning to decline, while the future of Orthoptera species such as crickets, katydids and grasshoppers looks dire.
The golden rule of terrestrial biology seems to be that no species lasts forever. In the distant past the Earth has gone through five major mass extinction events. The first of these was the Ordovician-Silurian mass extinction around 350,000,000 years ago and the last was the Cretaceous-Palaeogene mass extinction about 65,000,000 years ago.
The causes of these mass extinction events varies, but includes volcanism, climate change, gamma ray bursts from sunspot activity, an asteroid strike in the Cretaceous-Palaeogene period that led to the dinosaurs being killed off and other calamities. It is often the case where one cause triggers another such as when an asteroid struck the Earth at the end of the Cretaceous Period which caused dust to accumulate in the atmosphere blocking out the sun.
The number of species of flora and fauna under threat globally is rising. Mammals make up a quarter of this figure. This time it cannot be blamed on a rogue asteroid. The cause lies directly with human activity that is causing global warming, contamination of the seas, pollution of the atmosphere, mass deforestation and the wanton killing of species for pleasure and profit and more besides. If a rogue asteroid does strike it will add to the destruction and perhaps speed up the process of mass extinction which has already underway.
The loss of species
The WWF say the 23% or about 1,130 species of mammal and 12% of birds, about 1,195 species, are threatened. Over the last 500 years alone there has been reduction in the populations of 25% in all known species over the last 500 years that can be attributed to human activity. Not all groups of species have been affected equally. Around a third of all vertebrate species are believed to be threatened. Of the vertebrates the amphibians have been hit hard, with about 41% struggling for survival, while 17% of birds are affected up till now.
The degree to which insect species are affected varies across species. Butterflies are beginning to decline, while the future of Orthoptera species such as crickets, katydids and grasshoppers looks dire.
The root of the problem
There is no doubt that human activity is the cause of this problem. The overexploitation of animals and birds, in so many different ways, is taking a measurable toll. Killing animals for sheer pleasure or the resources they provide such as clothing, food, ivory, bone , body parts, pelts and hides is putting species such as tigers, elephants and rhinoceros to name just a few, into the endangered zone. But it is not just the cute, charismatic and famous animals that are disappearing
The destruction of habitat such as forests by logging, building roads, urbanization, farming and other human activities is destroying whole areas of plants and trees that were home to many different species of insects animals and birds continues at an alarming rate. Much of this flora and fauna are unknown or not as famous, cute or attractive as others but each has evolved its own unique place in the local ecosystem.
Their loss may seem trivial or unimportant and in the case of some such as reptiles and insects may at first seem welcoming. This is erroneous thinking because each and every species fulfils a role in the ecosystem. Losing one can slowly, or more dramatically unbalance the ecosystem affecting other species.
In the rainforests 25,000 square miles are destroyed each year, an area equivalent to the size of Panama. In some cases all it takes is a road or few building to be built in the wrong place, perhaps cutting off species from its food, water supply or breeding ground to begin a downward spiral that eventually affects other species. Unfortunately, so many human activities not mentioned also add to the problem.
Signs of ill omen
The Global Footprint Network was established in 2003 with the aim of enabling a sustainable future where humans live within the means of the Earth. The Global Footprint Network describes it self as
“… an international think tank working to advance sustainability through use of the Ecological Footprint, a resource accounting tool that measures how much nature we have, and how much we use. This tool is unique in making overshoot measurable – through detailed resource accounts for nations, cities and individuals. By working with governments, investors and opinion leaders we demonstrate the advantages of making ecological limits central to decision-making.”
One of the activities that the Global Footprint Network does is to estimate the natural resources humans are using against the natural resources that are available and then present their findings as a kind of budget for the year. Their latest estimates show that it takes humans less than 8 months to exhaust the annual budget. So in less than 8 months humans have spent the budget that is available for this year. The overshoot occurred on 19th of August of 2014, which they term Earth Overshoot Day 2014. They define global overshoot as,
“Global overshoot occurs when humanity's demand on nature exceeds the biosphere's supply, or regenerative capacity. Such overshoot leads to a depletion of Earth's life supporting natural capital and a build up of waste. At the global level, ecological deficit and overshoot are the same, since there is no net-import of resources to the planet. Local overshoot occurs when a local ecosystem is exploited more rapidly than it can renew itself.”
According to the Global Footprint Network estimates we are using more renewable resources and CO2 sequestration in 8 months than the Earth can supply for the whole year. In short, humans are using the Earth’s natural resources too fast for them to be replaced.
Disappearing bees
Global warming affects the weather changing whole ecosystems that were once thriving habitats supporting a wide variety of species. Sometimes what may seem a small insignificant species plays a key role in maintaining an ecosystem. Bees are becoming increasingly threatened but play a major role in the pollination of so many plant species.
Although they are not the only pollinators any loss of pollinators can spell trouble for an ecosystem, with around 75%of food crops relying on insects for their wellbeing. But it is not just with pollination that insects play a major part. They also help the nutrient cycle by breaking down dead organic matter that gives nutrients to the soil. These are mobile species but if they cannot travel from area to area and are not evenly spread as they live and die then the nutrient cycle breaks down.
Water quality
Water quality in streams, rivers, ponds and lakes depends on the interaction of a variety of organisms to prevent harmful algae blooms and to keep sufficient oxygen in the water. Poor water quality threatens many of the species that live within it, Invasive species of plant or other organisms to streams, rivers and lakes can takeover and threaten the life giving system because local organisms are not equipped to deal with the invaders.
Pest control
The removal of one species can have a profound effect on the population of another. The decline of the bat population in North America has encouraged an increase in insects that ruin crops. But it is not just the loss of bats and crops, farmers in North America are estimated to be losing $22 billion in lost harvest and on pesticide spending.
Invasive species
With the growth of world trade and the movement of goods many species are beginning to spread to new geographical regions. Some species get trapped in boxes and packaging and are sent out to new areas. Motor vehicles, trains, ships and aeroplanes all help the spread of species to regions where they have historically been absent. Sometimes they are imported as pets and escape or are brought in to fulfil a perceived role. Unfortunately these species can create havoc if they start breeding. Local traditional species may not be able to cope with them and die out as a result
But the life always bounces back!
Although life on Earth has bounced back from mass extinction events in the past at least five times and survived many lesser extinctions it does not necessarily mean humans are safe. Each time it has come back it has done so in different ways with different species evolving over long periods of time. Although humans like to think that we are at the centre of all things and in control nature does not necessarily agree. Nature does not necessarily work to suit humans so life may well bounce back but not necessarily human life.
There is no doubt that human activity is the cause of this problem. The overexploitation of animals and birds, in so many different ways, is taking a measurable toll. Killing animals for sheer pleasure or the resources they provide such as clothing, food, ivory, bone , body parts, pelts and hides is putting species such as tigers, elephants and rhinoceros to name just a few, into the endangered zone. But it is not just the cute, charismatic and famous animals that are disappearing
The destruction of habitat such as forests by logging, building roads, urbanization, farming and other human activities is destroying whole areas of plants and trees that were home to many different species of insects animals and birds continues at an alarming rate. Much of this flora and fauna are unknown or not as famous, cute or attractive as others but each has evolved its own unique place in the local ecosystem.
Their loss may seem trivial or unimportant and in the case of some such as reptiles and insects may at first seem welcoming. This is erroneous thinking because each and every species fulfils a role in the ecosystem. Losing one can slowly, or more dramatically unbalance the ecosystem affecting other species.
In the rainforests 25,000 square miles are destroyed each year, an area equivalent to the size of Panama. In some cases all it takes is a road or few building to be built in the wrong place, perhaps cutting off species from its food, water supply or breeding ground to begin a downward spiral that eventually affects other species. Unfortunately, so many human activities not mentioned also add to the problem.
Signs of ill omen
The Global Footprint Network was established in 2003 with the aim of enabling a sustainable future where humans live within the means of the Earth. The Global Footprint Network describes it self as
“… an international think tank working to advance sustainability through use of the Ecological Footprint, a resource accounting tool that measures how much nature we have, and how much we use. This tool is unique in making overshoot measurable – through detailed resource accounts for nations, cities and individuals. By working with governments, investors and opinion leaders we demonstrate the advantages of making ecological limits central to decision-making.”
One of the activities that the Global Footprint Network does is to estimate the natural resources humans are using against the natural resources that are available and then present their findings as a kind of budget for the year. Their latest estimates show that it takes humans less than 8 months to exhaust the annual budget. So in less than 8 months humans have spent the budget that is available for this year. The overshoot occurred on 19th of August of 2014, which they term Earth Overshoot Day 2014. They define global overshoot as,
“Global overshoot occurs when humanity's demand on nature exceeds the biosphere's supply, or regenerative capacity. Such overshoot leads to a depletion of Earth's life supporting natural capital and a build up of waste. At the global level, ecological deficit and overshoot are the same, since there is no net-import of resources to the planet. Local overshoot occurs when a local ecosystem is exploited more rapidly than it can renew itself.”
According to the Global Footprint Network estimates we are using more renewable resources and CO2 sequestration in 8 months than the Earth can supply for the whole year. In short, humans are using the Earth’s natural resources too fast for them to be replaced.
Disappearing bees
Global warming affects the weather changing whole ecosystems that were once thriving habitats supporting a wide variety of species. Sometimes what may seem a small insignificant species plays a key role in maintaining an ecosystem. Bees are becoming increasingly threatened but play a major role in the pollination of so many plant species.
Although they are not the only pollinators any loss of pollinators can spell trouble for an ecosystem, with around 75%of food crops relying on insects for their wellbeing. But it is not just with pollination that insects play a major part. They also help the nutrient cycle by breaking down dead organic matter that gives nutrients to the soil. These are mobile species but if they cannot travel from area to area and are not evenly spread as they live and die then the nutrient cycle breaks down.
Water quality
Water quality in streams, rivers, ponds and lakes depends on the interaction of a variety of organisms to prevent harmful algae blooms and to keep sufficient oxygen in the water. Poor water quality threatens many of the species that live within it, Invasive species of plant or other organisms to streams, rivers and lakes can takeover and threaten the life giving system because local organisms are not equipped to deal with the invaders.
Pest control
The removal of one species can have a profound effect on the population of another. The decline of the bat population in North America has encouraged an increase in insects that ruin crops. But it is not just the loss of bats and crops, farmers in North America are estimated to be losing $22 billion in lost harvest and on pesticide spending.
Invasive species
With the growth of world trade and the movement of goods many species are beginning to spread to new geographical regions. Some species get trapped in boxes and packaging and are sent out to new areas. Motor vehicles, trains, ships and aeroplanes all help the spread of species to regions where they have historically been absent. Sometimes they are imported as pets and escape or are brought in to fulfil a perceived role. Unfortunately these species can create havoc if they start breeding. Local traditional species may not be able to cope with them and die out as a result
But the life always bounces back!
Although life on Earth has bounced back from mass extinction events in the past at least five times and survived many lesser extinctions it does not necessarily mean humans are safe. Each time it has come back it has done so in different ways with different species evolving over long periods of time. Although humans like to think that we are at the centre of all things and in control nature does not necessarily agree. Nature does not necessarily work to suit humans so life may well bounce back but not necessarily human life.
Domesticating the Earth
Maybe we could preserve certain species of flora and fauna by domestication but how far can than this be taken? How will people respond to domesticated elephants and tigers being reared to supply human demands for ivory or body parts, or whales to supply flesh? After all, we have domesticated other animals such as pigs, cows, chickens and sheep. We have used selective breeding over hundreds of years to change them to what they are now purely to supply human demands. We could plant new forests with trees planted in perfectly straight lines all equally spaced. In fact we could domesticate the entire planet, but would that prevent the sixth great extinction event?
Even though humans are thriving like never before and we may think we are the dominant species today would that status remain? Mass extinctions usually take place over hundreds of thousand or even millions of years and humans living today may think it will not affect them. After the last five mass extinctions new dominant species emerged and even if we survive this sixth mass extinction, which we are busy creating, a whole new scenario may emerge which may not be one to our liking. It may not affect us so much now even though we can see the beginning, but it will affect future generations to come much more radically.
Maybe we could preserve certain species of flora and fauna by domestication but how far can than this be taken? How will people respond to domesticated elephants and tigers being reared to supply human demands for ivory or body parts, or whales to supply flesh? After all, we have domesticated other animals such as pigs, cows, chickens and sheep. We have used selective breeding over hundreds of years to change them to what they are now purely to supply human demands. We could plant new forests with trees planted in perfectly straight lines all equally spaced. In fact we could domesticate the entire planet, but would that prevent the sixth great extinction event?
Even though humans are thriving like never before and we may think we are the dominant species today would that status remain? Mass extinctions usually take place over hundreds of thousand or even millions of years and humans living today may think it will not affect them. After the last five mass extinctions new dominant species emerged and even if we survive this sixth mass extinction, which we are busy creating, a whole new scenario may emerge which may not be one to our liking. It may not affect us so much now even though we can see the beginning, but it will affect future generations to come much more radically.
References and Attributions
Copyright 23 August, 2014 zteve t evans
Copyright 23 August, 2014 zteve t evans
- WWF
- The Global Footprint Network
- Holocene extinction - Wikipedia, the free encyclopedia
- Earth is headed for its sixth mass extinction - study The Extinction Crisis - Center for Biological Diversity Has the Earth/'s sixth mass extinction already arrived? Sixth Great Extinction: We're to Blame - TIME