Negative impacts of humans on the environment

Without a doubt, humans have some harmful impacts on the environment.

Since we walked the Earth, we have changed our natural environment in one way or another. Certainly, it was not to harm it. Rather, we wanted to be more comfortable in it. We reshaped our surroundings for agriculture, travel and infrastructure.

Today, scientists believe that ‘original nature’ no longer exists.

Negative impacts of humans on the environment

Basically, the harmful effects of humans on the environment are:

• overpopulation,
• pollution,
• global warming,
• agriculture and
• deforestation.

1.      Overpopulation affects the environment

Currently, the worldwide population is around 7.7 billion people. By 2100, it will reach 11.2 billion people. With better medicine and lifestyles, mortality rates have substantially declined over the years.

In general, the number of births is decreasing in rich countries. But it is rising in vulnerable nations.

This makes the situation quite alarming for the environment. More humans mean more resources: food, space, fossil fuels.

Overconsumption

Basically, most resources that we use and consume come from finite sources. As consumption patterns change and we consume more, we put more pressure on our environment. And though rich countries may have lower populations, they consume more than vulnerable nations.

Right now, we are exceeding the Earth’s sustainable productivity by 60%. Socio-biologist, Wilson Edward further estimates that the Earth can support only around 9-10 billion people in a sustainable manner.

Waste production

At the same time, we also produce more waste. As a matter of fact, we now generate 10 times more waste than in the last century. But disposal abilities remain limited. Most of our landfills are filling up quickly. Many poor nations then burn their waste which further adds to air pollution and leads to health problems.

While we can recycle and reuse certain items like paper, there are others that stay in the environment for a long time. Plastic is such a deadly example. It can take between 100 to 500 years to decompose.

Plastic pollution

Today, we are facing many challenges because plastic clogs rivers and channels leading to flooding. Sea creatures also eat or get trapped in plastic thus killing them.

2.      Impacts of pollution on the environment

Pollution is when we add foreign material into the environment, which can eventually change it.

Unfortunately, pollution is now also a major problem. Through so many of our activities, we introduce alien materials into the air, water and land. When we drive vehicles, we release toxic gases. As we sail in boats, motor oil goes into the water. And when we change land uses, we affect other ecosystems.

In China alone, 1 million people die every year because of air pollution. Likewise, we are now heavily affecting marine habitats all over the world. Unregulated activities release sewage and trash into the oceans.

Excessive fertilizers that farmers use also run into the sea. Today, we have 500 dead zones globally over an area of 245,000 km² resulting from excess nutrients.

Acid rain

What’s more, we also release sulphur dioxide and nitrogen oxides into the atmosphere when we burn fossil fuels and use heavy vehicle equipment.

These gases mix with condensing clouds and fall down as acid rain. Acid rain can ruin solid materials on land like statues and change the pH of the soil.

In many developing countries in Asia, scientists noted a decrease in crop yields and tree growth due to acid rain.

Nevertheless, the effect of acid rain in water is even worse as it changes the pH of the water. This can cause entire marine populations to collapse.

Ocean acidification

In general, many human activities release carbon dioxide like burning fossil fuels. Ocean acidification occurs when carbon dioxide mixes with seawater to form a weak carbonic acid.

However, this acid can greatly reduce the pH of seawater leading to deadly effects.

In fact, the amount of carbon dioxide in our oceans today is higher than what we observe in the last 800,000 years. The pH of seawater has actually increased by 0.1 unit because of this.

Such changes can also affect the formation of calcium carbonate which is the main component of the shells of crustaceans.

3.   Global warming and climate change

One of the worst problems that exists today is global warming.

Global warming refers to the increase in temperature on Earth. Though the temperature of the planet rose and fell a number of times in the past, today, scientists believe that it is mostly due to human activities. Especially, the burning of fossil fuels that releases greenhouse gases like carbon dioxide.

This carbon dioxide stays in the atmosphere and absorbs heat thus increasing the temperature on Earth. Since the late 19^th century, the temperature has actually risen by 0.9°C.

As a matter of fact, before pre-industrial times, the level of carbon dioxide was less than 300 PPM. Right now, it is around 440 PPM.

Climate change

As the planet heats up, it also changes the global climate. We now have more recurrent storms, floods, droughts and epidemics because of climate change. Scientists estimate that these will only get worse in the future. For example, as glaciers melt, the sea level rises. This can cause many atoll nations to eventually disappear.

4.      Agriculture has serious consequences on our environment

As it turns out, agriculture itself has its load of harmful impacts on the environment such as

• point source pollution,
• excessive use of water for irrigation and stream modification,
• use of pesticides and herbicides that leak into water bodies,
• clearing forests and riparian zones to grow crops,
• grazing by cattle and the
• release of greenhouse gases into the atmosphere by cattle and the use of fossil fuels.

Gene modification

In addition to these, we also manipulate various plant and animal species for our own benefit. We call them Genetically Modified Organisms (GMO). We alter the genome of these organisms to get better and higher yields and to make them more resistant.

Over the years, gene modification advanced tremendously. We can now incorporate the genes from a different species into another organism to get the results we want. As it is, such advances help considerably in the food and medicinal sectors.

However, gene manipulation is a very risky process. The outcome may be unintended or a by-product of the process. Sometimes, organisms may even mutate and become resistant. Superweeds, for example, are now choking agricultural crops. Likewise, 249 species of weeds can presently resist 22 out of 25 known herbicides.

5.      Deforestation and forest degradation

Since the 1960s, we have destroyed more than half of the tropical forests. In Europe alone, cattle, diseases, fire and human activities damaged some 3.7 million hectares of forests.

Every year, we lose 18.7 million acres of forests due to agriculture and illegal logging. Strikingly, we cleared 17% of the rich Amazonian forest in the past 50 years to give way to cattle ranches.

As it is, forests are the lungs of the planet. They filter polluted air and take in carbon dioxide to produce oxygen for life to continue on Earth. When we cut down trees, carbon dioxide stays in the air. And the level of air pollution also increases.

Threaten biodiversity

Likewise, deforestation and forest degradation threaten biodiversity directly. Some plant and animal species may go extinct in the wild when we destroy their habitats. At the same time, other animals, such as elephants, may migrate towards human settlement and cause damages. As a result, frightened villagers may kill them.