Category: Ecology

All of the organisms present on our planet interact in a balanced cycle with their environment. Using the energy from sunlight, the plants convert water, carbon dioxide, and minerals absorbed from the earth into food. The plants then become food for the herbivores and the carnivores prey on these creatures. When the plants and animals die, the micro-organisms consume them.

In recent times, this cycle has been under some serious threat. This is largely due to pollution and the uncontrolled use of natural resources by the humans. However, we humans can take some effective measures to ensure that the planet maintains the ecological balance. Here are some of them:

1. Population control

Human beings don’t have any natural predators that can keep their population under control. It is, therefore, extremely necessary that we take some urgent steps to control our population. Action needs to be taken at the individual as well as government level. The uncontrolled growth of population can severely upset the ecological balance in the days to come.

This is just like the scenario where too many fish spoil the quality of water in an aquarium. Earth’s overall population would reach 9 billion by the year 2050 according to the latest estimates. The only way to control such an increase in population is to reduce the birth rate. This can be done through family planning and contraception.

2. Careful management of resources

Fossil fuels, minerals, and other natural resources won’t be here forever. Their continued use by an ever-increasing population of humans places a heavy burden on the ecosystem. Besides this, over-fishing and habitat destruction causes a considerable loss of biodiversity.

This can negatively impact the ecosystem in the long term. An entire marine ecosystem can be under threat by the loss of a few species. It is the need of the hour to use all such natural resources in a sustainable way.

3. Preventing water pollution

Manufacturing units, agricultural runoffs, and sewage are some of the major sources of water pollution. Algae grow rapidly in lakes and streams owing to the run-offs of agricultural fertilizers and sewage. This leads to the blockage of sunlight and depletion of oxygen in the water bodies. As a result, the amount of natural plant life reduces in the marine ecosystem.

It causes a reduction in the population of marine beings feeding on these plants. The population of marine creatures consuming these plant-eating beings also reduces as a consequence. There’s an urgent need, therefore, to prevent the contamination of waters from various sources.

4. Recycling

Manufacturing of new products using recycled materials is a good way of lessening the demand for natural resources. It also reduces the need to over-harvest natural resources, thus maintaining the balance of ecosystems on the planet. Recycling the waste materials reduces pollution to a great extent. Since there are no new raw materials involved, there are no additional wastes generated.

We can understand this better from the example of paper. Recycling paper can help save many trees from being felled, thus conserving the forest areas. Aluminum cans, glass containers, and egg cartons are a few examples of materials that can be recycled.

In the mid-19th century, the best-selling book On the Origin of Species was published. Through this book, the English naturalist Charles Darwin brought the idea of natural selection to the world’s attention. He had developed this idea after his voyage to South America and the Pacific islands.

The purpose of his journey was to study various plants, fossils, and animals. The populations of living organisms adapt and change through a natural process. Charles Darwin popularized this process while also giving it the term ‘natural selection’.

In a population, all the individuals are variable in some ways. In this variation, some individuals have traits that are best suited to the environment than others in the population. These adaptive traits give them better chances of survival and reproduction. Such individuals then pass on these traits to their offspring.

Over a period of time, these adaptive traits become more common in the population of the species. Let’s take the population’s height as an example. It can be observed that the heights of individuals in the population vary. This happens without any selection pressures with regards to height.

While most of the individuals in the population would be of an average height, some can be extremely tall or extremely short. This distribution would be altered when selection pressures act on a trait such as height. Now, let’s take a look at the types of natural selection:

1. Stabilizing selection

A population experiences this type of natural selection when the selective pressures select against a trait’s two extremes. For instance, stabilizing selection might act on the height of a tree. One that is too short won’t be able to compete for sunlight with other trees. However, the taller ones may be more likely to suffer damages from the winds.

The combination of these selection pressures maintain a medium height of these trees. As a result, the numbers of taller and shorter trees would decrease. On the other hand, the numbers of trees with medium height would increase.

2. Directional selection

In this type, one extreme of the distribution of a trait is subject to selection against it. This results in a shift of trait distribution in the population towards the other extreme. The mean of the population graph shifts in directional selection. We can understand this from the example of giraffe necks.

In the population of giraffes, the individuals with short necks could not reach many leaves to feed themselves. So, there was a selection pressure against the ones with short necks. As a result, the distribution of neck length went in favor of the ones with long necks.

3. Disruptive selection

The pressures of selection act against those in the middle of the trait distribution in disruptive selection. This results in a two-peaked or bimodal curve. The two extremes of this curve form their own smaller curve. Let’s take a plant species as an example here, which is of extremely variable height. In these plants, the pollination happens through three different pollinators.

One has an attraction towards shorter plants, while the second prefer the ones with medium height. The third visits only the tallest plants. Now, let’s assume that the pollinator having a preference for plants with medium height disappears from an area. In this case, the selection would be towards the shorter and taller plants.

With the growth in global population, the world experiences an ecological overshoot. It’s a situation where a population’s demand exceeds an ecosystem’s capacity to regenerate the resources and absorb its wastes. The use of ecological footprint is often useful in calculating the global ecological overshoot.

An ecological overshoot is a serious threat to Earth’s biological capital. It leads to the depletion of the planet’s natural resources and results in an accumulation of waste materials. Humans continue to use the resources provided by nature in an uncontrolled manner. This would eventually exceed the planet’s regenerating abilities.

This is why there have been frequent calls for countries and their populations to reduce their ecological footprint. One of the greatest evidences of ecological overshoot is the rising water shortages in certain parts of the world. The other evidences include reduced agricultural productivity, desertification, loss of biodiversity, deforestation, and the build-up of carbon dioxide.

Efforts to reduce carbon emissions

Reducing the Earth’s carbon footprint is certainly the need of the hour. This would bring down the ecological footprint of the planet considerably. As the two have an inextricable association, decreasing the carbon footprint would have a positive effect on other components. Among them are lands that people need for timber and food production and forests that can absorb carbon.

In the year 2015, carbon sequestration was a top priority of the Earth Overshoot Day’s promoters. Carbon sequestration is the process of separating and storing carbon dioxide. Such initiatives can be effective in highlighting how important it is to reduce the planet’s carbon footprint.

The current levels of carbon emissions are quite significant. It would take twice the bio-capacity of global forests that currently exists to absorb all the carbon emissions. In recent times, the demand for carbon sequestration has been greater than ever before. In fact, it is greater than all the bio-capacity of the planet’s crop lands and grazing lands taken together.

Every year, the sustainable think tank of the world comes up with certain calculations. It estimates whether the planet’s biological resources are adequate for the world’s ecological footprint for that particular year. Until the early 1970s, Earth’s ecological footprint was below the planet’s biocapacity. The problems began showing up towards the end of the 20th century.

The current state of ecological overshoot

Today, the planet’s ecological footprint has increased drastically. If the world continues along this current trajectory, it would need the resources of two planets after a few years. The situation currently is such that it takes 1.6 Earths to support the demands of the existing population. It is absolutely necessary that the global community takes note of these facts.

There must be a consensus on the need to phase out fossil fuels as early as possible. A few other measures must be taken to maintain global warming within 2-degree Celsius. Along with this, a reduction in global carbon emissions by at least 30% is also necessary.

If this is done successfully, the ecological overshoot can be brought down significantly. Although there hasn’t been a major impact of these efforts until now, there’s still some hope. If more of such initiatives are taken globally, then things would improve to a great extent.